OBJECTIVE

The MOSAIC (Multicenter International Study of Oxaliplatin/Fluorouracil/Leucovorin in the Adjuvant Treatment of Colon Cancer) study has demonstrated 3-year disease-free survival (DFS) and 6-year overall survival (OS) benefit of adjuvant oxaliplatin in stage II to III resected colon cancer. This update presents 10-year OS and OS and DFS by mismatch repair (MMR) status and BRAF mutation.

METHODS

Survival actualization after 10-year follow-up was performed in 2,246 patients with resected stage II to III colon cancer. We assessed MMR status and BRAF mutation in 1,008 formalin-fixed paraffin-embedded specimens.

RESULTS

After a median follow-up of 9.5 years, 10-year OS rates in the bolus/infusional fluorouracil plus leucovorin (LV5FU2) and LV5FU2 plus oxaliplatin (FOLFOX4) arms were 67.1% versus 71.7% (hazard ratio [HR], 0.85; P = .043) in the whole population, 79.5% versus 78.4% for stage II (HR, 1.00; P = .980), and 59.0% versus 67.1% for stage III (HR, 0.80; P = .016) disease. Ninety-five patients (9.4%) had MMR-deficient (dMMR) tumors, and 94 (10.4%) had BRAF mutation. BRAF mutation was not prognostic for OS (P = .965), but dMMR was an independent prognostic factor (HR, 2.02; 95% CI, 1.15 to 3.55; P = .014). HRs for DFS and OS benefit in the FOLFOX4 arm were 0.48 (95% CI, 0.20 to 1.12) and 0.41 (95% CI, 0.16 to 1.07), respectively, in patients with stage II to III dMMR and 0.50 (95% CI, 0.25 to 1.00) and 0.66 (95% CI, 0.31 to 1.42), respectively, in those with BRAF mutation.

CONCLUSIONS

The OS benefit of oxaliplatin-based adjuvant chemotherapy, increasing over time and with the disease severity, was confirmed at 10 years in patients with stage II to III colon cancer. These updated results support the use of FOLFOX in patients with stage III disease, including those with dMMR or BRAF mutation.

A total of 343 patients with previously untreated metastatic measurable colorectal carcinoma were studied to evaluate the impact on toxicity, response, and survival of leucovorin-modulated fluorouracil (5-FU). A maximally tolerated intravenous bolus loading course regimen of 5-FU alone (500 mg/m2 x 5 days every 4 weeks with 25 mg/m2 escalation) was compared with a high-dose leucovorin regimen (600 mg/m2 of 5-FU with 500 mg/m2 of leucovorin weekly for 6 weeks with a 2-week rest) and with a similar low-dose leucovorin regimen (600 mg/m2 of 5-FU with 25 mg/m2 of leucovorin weekly for 6 weeks with a 2-week rest). The dose-limiting toxicity for the two 5-FU and leucovorin regimens was gastrointestinal, specifically diarrhea; severe diarrhea was seen frequently, and treatment-related toxicity was implicated in the demise of 11 of the patients (5%). Significant improvements in response rates were observed with a response rate of 33 of 109 (30.3%) on the high-dose leucovorin regimen (P less than .01 v control); 13 of 107 (12.1%) on the 5-FU control; and 21 of 112 (18.8%) on the low-dose leucovorin regimen. A trend toward longer survival in the 5-FU plus high-dose leucovorin regimen was observed. In this study, leucovorin was shown to significantly enhance the therapeutic effect of 5-FU in metastatic colorectal carcinoma.

BACKGROUND

The conviction that postoperative radiotherapy and chemotherapy represent an acceptable standard of care for patients with Dukes' B (stage II) and Dukes' C (stage III) carcinoma of the rectum evolved in the absence of data from clinical trials designed to determine whether the addition of radiotherapy results in improved disease-free survival and overall survival. This study was carried out to address this issue. An additional aim was to determine whether leucovorin (LV)-modulated 5-fluorouracil (5-FU) is superior to the combination of 5-FU, semustine, and vincristine (MOF) in men.

METHODS

Eligible patients (n = 694) with Dukes' B or C carcinoma of the rectum were enrolled in National Surgical Adjuvant Breast and Bowel Project (NSABP) Protocol R-02 from September 1987 through December 1992 and were followed. They were randomly assigned to receive either postoperative adjuvant chemotherapy alone (n = 348) or chemotherapy with postoperative radiotherapy (n = 346). All female patients (n = 287) received 5-FU plus LV chemotherapy; male patients received either MOF (n = 207) or 5-FU plus LV (n = 200). Primary analyses were carried out by use of a stratified log-rank statistic; P values are two-sided.

RESULTS

The average time on study for surviving patients is 93 months as of September 30, 1998. Postoperative radiotherapy resulted in no beneficial effect on disease-free survival (P =.90) or overall survival (P =.89), regardless of which chemotherapy was utilized, although it reduced the cumulative incidence of locoregional relapse from 13% to 8% at 5-year follow-up (P =.02). Male patients who received 5-FU plus LV demonstrated a statistically significant benefit in disease-free survival at 5 years compared with those who received MOF (55% versus 47%; P =.009) but not in 5-year overall survival (65% versus 62%; P =.17).

CONCLUSIONS

The addition of postoperative radiation therapy to chemotherapy in Dukes' B and C rectal cancer did not alter the subsequent incidence of distant disease, although there was a reduction in locoregional relapse when compared with chemotherapy alone.

Previous studies have identified high numbers of intraepithelial T lymphocytes to be associated with good prognosis in various types of cancer. Few studies addressing this issue have been published for colorectal cancer. In a simulated prospective approach ("phase II prognostic factor study"), all nonmetachronous International Union Against Cancer (UICC) stage III colorectal cancers that were accessioned in the years 1994 to 1999 were included in the study (152 cases). Follow-up information as to vital status and occurrence of metachronous metastases could be obtained for all patients in the years 2001 and 2002. CD8+ intratumoral lymphocytes were quantified after immunostaining and referred to tumor cell area (CD8+ densities). Microsatellite status was determined by using the Bethesda panel of microsatellite markers. CD8+ densities ranged from 0 per square millimeter to 1436 per square millimeter of tumor area in a nonnormal distribution that was skewed toward low values. Univariate survival analyses revealed the 66th percentile as a stringent cutoff (CD8+high versus CD8+low), with CD8+high cases taking a significantly better clinical course. This prognostic impact appeared even more pronounced in the subset of patients with colon carcinomas who were receiving 5-fluouracil/leucovorin as adjuvant treatment (79 patients). Seventeen patients had carcinomas with high microsatellite instability (MSI-H). MSI-H-CD8+high cases (n = 11) showed an excellent prognosis, with tumor-free survival for 9 of the 11 patients. The prognostic effect of CD8+high was retained in Cox regression analyses when including UICC substages (IIIA to IIIC). Our results identify CD8+ tumor-infiltrating lymphocytes as a promising candidate for further evaluation in the ongoing search for prognostic and predictive factors of colorectal cancer, particularly if combined with microsatellite status.

Since 2004, a regimen of 6 months of treatment with oxaliplatin plus a fluoropyrimidine has been standard adjuvant therapy in patients with stage III colon cancer. However, since oxaliplatin is associated with cumulative neurotoxicity, a shorter duration of therapy could spare toxic effects and health expenditures.

We performed a prospective, preplanned, pooled analysis of six randomized, phase 3 trials that were conducted concurrently to evaluate the noninferiority of adjuvant therapy with either FOLFOX (fluorouracil, leucovorin, and oxaliplatin) or CAPOX (capecitabine and oxaliplatin) administered for 3 months, as compared with 6 months. The primary end point was the rate of disease-free survival at 3 years. Noninferiority of 3 months versus 6 months of therapy could be claimed if the upper limit of the two-sided 95% confidence interval of the hazard ratio did not exceed 1.12.

After 3263 events of disease recurrence or death had been reported in 12,834 patients, the noninferiority of 3 months of treatment versus 6 months was not confirmed in the overall study population (hazard ratio, 1.07; 95% confidence interval [CI], 1.00 to 1.15). Noninferiority of the shorter regimen was seen for CAPOX (hazard ratio, 0.95; 95% CI, 0.85 to 1.06) but not for FOLFOX (hazard ratio, 1.16; 95% CI, 1.06 to 1.26). In an exploratory analysis of the combined regimens, among the patients with T1, T2, or T3 and N1 cancers, 3 months of therapy was noninferior to 6 months, with a 3-year rate of disease-free survival of 83.1% and 83.3%, respectively (hazard ratio, 1.01; 95% CI, 0.90 to 1.12). Among patients with cancers that were classified as T4, N2, or both, the disease-free survival rate for a 6-month duration of therapy was superior to that for a 3-month duration (64.4% vs. 62.7%) for the combined treatments (hazard ratio, 1.12; 95% CI, 1.03 to 1.23; P=0.01 for superiority).

Among patients with stage III colon cancer receiving adjuvant therapy with FOLFOX or CAPOX, noninferiority of 3 months of therapy, as compared with 6 months, was not confirmed in the overall population. However, in patients treated with CAPOX, 3 months of therapy was as effective as 6 months, particularly in the lower-risk subgroup. (Funded by the National Cancer Institute and others.).

OBJECTIVE

In the West, curative (R0) resection is achieved in approximately 50% of patients with localized gastric carcinoma, and more than 60% die of cancer following an R0 resection. A multi-institutional study of preoperative chemoradiotherapy was done to assess the R0 resection rate, pathologic complete response (pathCR) rate, safety, and survival in patients with resectable gastric carcinoma.

METHODS

Operable patients with localized gastric adenocarcinoma were eligible. Staging also included a laparoscopy and endoscopic ultrasonography (EUS). Patients received up to two 28-day cycles of induction chemotherapy of fluorouracil, leucovorin, and cisplatin, followed by 45 Gy of radiation plus concurrent fluorouracil. Patients were then staged and surgery was attempted.

RESULTS

Thirty-four patients were registered at three institutions. One ineligible patient was excluded. Most patients had a promixal cancer and EUST3N1 designation. Twenty-eight (85%) of 33 patients underwent surgery. The R0 resection rate was 70% and pathCR rate was 30%. A pathologic partial response (< 10% residual carcinoma in the primary) occurred in eight patients (24%). EUS T plus N and postsurgery T plus N correlation showed significant downstaging (P = <.01). The median survival time for 33 patients was 33.7 months. Patients achieving a pathCR or pathPR had a significantly longer median survival time (63.9 months) than those achieving less than pathPR (12.6 months; P =.03). There were two treatment-related deaths.

CONCLUSIONS

Our data suggest that the three-step strategy of preoperative induction chemotherapy followed by chemoradiotherapy resulted in substantial pathologic response that resulted in durable survival time. This strategy is worthy of a direct comparison with postoperative adjuvant chemoradiotherapy.

BACKGROUND

5-fluorouracil, leucovorin, irinotecan and oxaliplatin (FOLFIRINOX) is superior to gemcitabine in patients with metastatic pancreatic cancer who have a good performance status. We investigated this combination as neoadjuvant therapy for locally advanced pancreatic cancer (LAPC).

METHODS

In this retrospective series, we included patients with unresectable LAPC who received neoadjuvant FOLFIRINOX with growth factor support. The primary analysis endpoint was R0 resection rate.

RESULTS

Eighteen treatment-naïve patients with unresectable or borderline resectable LAPC were treated with neoadjuvant FOLFIRINOX. The median age was 57.5 years and all had ECOG PS of 0 or 1. Eleven (61 %) had tumors in the head of the pancreas and 9 (50 %) had biliary stents placed prior to chemotherapy. A total of 146 cycles were administered with a median of 8 cycles (range 3-17) per patient. At maximum response or tolerability, 7 (39 %) were converted to resectability by radiological criteria; 5 had R0 resections, 1 had an R1 resection, and 1 had unresectable disease. Among the 11 patients who remained unresectable after FOLFIRINOX, 3 went on to have R0 resections after combined chemoradiotherapy, giving an overall R0 resection rate of 44 % (95 % CI 22-69 %). After a median follow-up of 13.4 months, the 1-year progression-free survival was 83 % (95 % CI 59-96 %) and the 1-year overall survival was 100 % (95 % CI 85-100 %). Grade 3/4 chemotherapy-related toxicities were neutropenia (22 %), neutropenic fever (17 %), thrombocytopenia (11 %), fatigue (11 %), and diarrhea (11 %). Common grade 1/2 toxicities were neutropenia (33 %), anemia (72 %), thrombocytopenia (44 %), fatigue (78 %), nausea (50 %), diarrhea (33 %) and neuropathy (33 %).

CONCLUSIONS

FOLFIRINOX followed by chemoradiotherapy is feasible as neoadjuvant therapy in patients with unresectable LAPC. The R0 resection rate of 44 % in this population is promising. Further studies are warranted.

This study evaluates the efficacy of capecitabine using data from a large, well-characterised population of patients with metastatic colorectal cancer (mCRC) treated in two identically designed phase III studies. A total of 1207 patients with previously untreated mCRC were randomised to either oral capecitabine (1250 mg m(-2) twice daily, days 1-14 every 21 days; n=603) or intravenous (i.v.) bolus 5-fluorouracil/leucovorin (5-FU/LV; Mayo Clinic regimen; n=604). Capecitabine demonstrated a statistically significant superior response rate compared with 5-FU/LV (26 vs 17%; P<0.0002). Subgroup analysis demonstrated that capecitabine consistently resulted in superior response rates (P<0.05), even in patient subgroups with poor prognostic indicators. The median time to response and duration of response were similar and time to progression (TTP) was equivalent in the two arms (hazard ratio (HR) 0.997, 95% confidence interval (CI) 0.885-1.123, P=0.95; median 4.6 vs 4.7 months with capecitabine and 5-FU/LV, respectively). Multivariate Cox regression analysis identified younger age, liver metastases, multiple metastases and poor Karnofsky Performance Status as independent prognostic indicators for poor TTP. Overall survival was equivalent in the two arms (HR 0.95, 95% CI 0.84-1.06, P=0.48; median 12.9 vs 12.8 months, respectively). Capecitabine results in superior response rate, equivalent TTP and overall survival, an improved safety profile and improved convenience compared with i.v. 5-FU/LV as first-line treatment for MCRC. For patients in whom fluoropyrimidine monotherapy is indicated, capecitabine should be strongly considered. Following encouraging results from phase I and II trials, randomised trials are evaluating capecitabine in combination with irinotecan, oxaliplatin and radiotherapy. Capecitabine is a suitable replacement for i.v. 5-FU as the backbone of colorectal cancer therapy.

Twenty patients with osteogenic sarcoma of the distal portion of the femur and the proximal portion of the tibia received chemotherapy (vincristine sulfate, methotrexate with leucovorin calcium rescue, [citrovorum factor; folinade calcium], and doxorubicin hydrochloride [Adriamycin]), followed by radical en bloc resection and prosthetic bone replacement. Histologic examination of surgical specimens obtained after chemotherapy showed variable degrees of tumor destruction and, in some cases, massive tumor necrosis, attesting to the profound effects of vigorous chemotherapy. This new therapeutic regimen, when feasible, may prove to be the treatment of choice in osteogenic sarcoma.

ABCG2 is a plasma membrane efflux pump that is able to confer resistance to several anticancer agents, including mitoxantrone, camptothecins, anthracyclines, and flavopiridol. The antimetabolite methotrexate (MTX) was inferred recently to be an additional substrate of the pump based on the analysis of ABCG2-overexpressing cell lines. However, the transport characteristics of the pump with regard to this agent have not been determined. In addition, physiological substrates of ABCG2 have not been identified. Here we examine the in vitro transport properties of the pump using membrane vesicles prepared from HEK293 cells transfected with ABCG2 expression vector. In so doing it is shown that MTX is a high capacity low affinity substrate of the pump, with K(m) and V(max) values of 1.34 +/- 0.18 mM and 687 +/- 87 pmol/mg/min, respectively. Unlike previously characterized multidrug resistance protein family members, ABCG2 is also able to transport MTX diglutamate and MTX triglutamate. However, addition of even one more glutamyl residue is sufficient to completely abrogate ABCG2-mediated transport. By contrast with the wild-type protein (ABCG2-R482), two ABCG2 variants that have been identified in drug selected cell lines, R482T and R482G, were unable to transport MTX to any extent. Similarly, folic acid was subject to efflux by the wild-type protein but not by the two mutants. However, transport of the reduced folate leucovorin was not detected for either the wild-type or the mutant proteins. Finally, it is shown that ABCG2 is capable of transporting E(2)17betaG with K(m) and V(max) values of 44.2 +/- 4.3 micro M and 103 +/- 17 pmol/mg/min, respectively. These results indicate that ABCG2 is a component of the energy-dependent efflux system for certain folates and antifolates, but that its transport characteristics with respect to polyglutamates and reduced folates are not identical to those of multidrug resistance protein family members. In addition, it is demonstrated that R482 mutations observed in drug-resistant cell lines have profound effects on the in vitro transport properties of the pump.

BACKGROUND

Docetaxel-based chemotherapy is effective in metastatic gastric and gastro-oesophageal junction adenocarcinoma, but has not yet been evaluated in the context of resectable patients. Here we report findings from the phase 2 part of the phase 2/3 FLOT4 trial, which compared histopathological regression in patients treated with a docetaxel-based triplet chemotherapy versus an anthracycline-based triplet chemotherapy before surgical resection.

METHODS

In this randomised, open-label, phase 2/3 study, eligible participants were recruited from 28 German oncology centres. Patients with resectable gastric or gastro-oesophageal junction cancer who had clinical stage cT2 or higher, nodal positive (cN+) disease, or both were randomly assigned (1:1) to either three preoperative and three postoperative 3-week cycles of intravenous epirubicin 50 mg/m2 on day 1, intravenous cisplatin 60 mg/m2 on day 1, and either fluorouracil 200 mg/m2 as continuous intravenous infusion or capecitabine 1250 mg/m2 orally (two doses of 625 mg/m2 per day) on days 1 to 21 (ECF/ECX group) or four preoperative and four postoperative 2-week cycles of docetaxel 50 mg/m2, intravenous oxaliplatin 85 mg/m2, intravenous leucovorin 200 mg/m2, and fluorouracil 2600 mg/m2 as a 24 h infusion, all on day 1 (FLOT group). Randomisation was done centrally with an interactive web-response system based on a sequence generated with blocks (block size 2) stratified by Eastern Cooperative Oncology Group performance status, location of primary tumour, age, and nodal status. No masking was done. Central assessment of pathological regression was done according to the Becker criteria. The primary endpoint was pathological complete regression (tumour regression grade TRG1a) and was analysed in the modified intention-to-treat population, defined as all patients who were randomly assigned to treatment excluding patients who had surgery but did not provide resection specimens for central evaluation. The study (including the phase 3 part) has completed enrolment, but follow-up is ongoing and this is an interim analysis. The trial is registered with ClinicalTrials.gov, number NCT01216644.

RESULTS

Between Aug 18, 2010, and Aug 10, 2012, 300 patients (152 patients in the ECF/ECX group; 148 patients in the FLOT group) were enrolled into the phase 2 part of the study, 265 of whom (137 in the ECF/ECX group; 128 in the FLOT group) were assessable on a modified intention-to-treat basis. 119 (93%) of 128 patients in the FLOT group and 126 (92%) of 137 patients in the ECF/ECX group were given all planned preoperative cycles of treatment. FLOT was associated with significantly higher proportions of patients achieving pathological complete regression than was ECF/ECX (20 [16%; 95% CI 10-23] of 128 patients vs eight [6%; 3-11] of 137 patients; p=0·02). 44 (40%) of 111 patients in the ECF/ECX group and 30 (25%) of 119 patients in the FLOT group had at least one serious adverse event involving a perioperative medical or surgical complication. The most common non-surgical grade 3-4 adverse events were neutropenia (52 [38%] of 137 patients in the ECF/ECX group vs 67 [52%] of 128 patients in the FLOT group), leucopenia (28 [20%] vs 36 [28%]), nausea (23 [17%] vs 12 [9%]), infection (16 [12%] vs 15 [12%]), fatigue (19 [14%] vs 11 [9%]), and vomiting (13 [10%] vs four [3%]).

CONCLUSIONS

Perioperative FLOT was active and feasible to administer, and might represent an option for patients with locally advanced, resectable gastric or gastro-eosophageal junction adenocarcinoma.

BACKGROUND

None.

OBJECTIVE

To define the value of thymidylate synthase (TS), Ki-67, and p53 as prognostic markers in patients with stage II and III colon carcinoma.

METHODS

We retrospectively analyzed the prognostic value of TS, Ki-67, and p53 in 706 patients with Dukes' B (291 patients) or Dukes' C (415 patients) colon carcinoma who were treated with either surgery alone (275 patients) or surgery plus fluorouracil (FU)-leucovorin chemotherapy (431 patients) in National Surgical Adjuvant Breast and Bowel Project (NSABP) protocols C01-C04. All three markers were assayed using immunohistochemical techniques.

RESULTS

Using 5 years of follow-up data, our retrospective analysis demonstrated an association between TS intensity (relapse-free survival [RFS]: risk ratio [RR] = 1.46, P =.01; overall survival [OS]: RR = 1.54, P =.002), Ki-67 (RFS: RR = 0.76, P =.05; OS: RR = 0.62, P =.001), and p53 (RFS: RR = 1.49, P =.01; OS: RR = 1.21, P =.18) for RFS and OS. High TS intensity levels and positive p53 staining were associated with a worse outcome. Tumors containing a high percentage of Ki-67-positive cells enjoyed an improved outcome compared with those patients whose tumors contained relatively few positive cells. An interaction with treatment was not identified for any of the markers.

CONCLUSIONS

This retrospective investigation demonstrated that TS, Ki-67, and p53 staining each had significant prognostic value for patients with Dukes' B and C colon carcinoma. However, none of the markers could be used to clearly discern groups of individuals who would be predicted to derive greater or lesser benefit from the use of adjuvant chemotherapy.

To compare the efficacy and toxicity of oxaliplatin (L-OHP) in combination with irinotecan (CPT-11), 5-fluorouracil (5-FU) and leucovorin (LV) (FOLFOXIRI) vs irinotecan and 5-FU/LV (FOLFIRI) as first-line treatment of patients with metastatic colorectal cancer (MCC). A total of 283 chemotherapy-naïve patients with MCC were enrolled (FOLFIRI arm: n=146; FOLFOXIRI arm: n=137). In the FOLFOXIRI arm, CPT-11 (150 mg m(-2)) was given on d1, L-OHP (65 mg m(-2)) on d2, LV (200 mg m(-2)) on days 2 and 3 and 5-FU (400 mg m(-2) as i.v. bolus and 600 mg m(-2) as 22 h i.v. continuous infusion) on days 2 and 3. In the FOLFIRI arm, CPT-11 (180 mg m(-2)) was given on d1 whereas LV and 5-FU were administered in the same way as in the FOLFOXIRI regimen. Both regimens were administered every 2 weeks. There was no difference in terms of overall survival (median OS: 19.5 and 21.5 months, for FOLFIRI and FOLFOXIRI, respectively; P=0.337), median time to disease progression (FOLFIRI: 6.9 and FOLFOXIRI: 8.4 months; P=0.17), response rates (33.6 and 43% for FOLFIRI and FOLFOXIRI, respectively; P=0.168). Patients treated with FOLFOXIRI had a significantly higher incidence of alopecia (P=0.0001), diarrhoea (P=0.0001) and neurosensory toxicity (P=0.001) compared with patients treated with FOLFIRI. The present study failed to demonstrate any superiority of the FOLFOXIRI combination compared with the FOLFIRI regimen, although the observed median OS is one of the best ever reported in the literature.

OBJECTIVE

Alterations in the RAS and RAF pathway relate to epigenetic and epigenomic aberrations, and are important in colorectal carcinogenesis. KRAS mutation in metastatic colorectal cancer predicts resistance to anti-epidermal growth factor receptor (EGFR)-targeted therapy (cetuximab or panitumumab). It remains uncertain, however, whether KRAS mutation predicts prognosis or clinical outcome of colon cancer patients independent of anti-EGFR therapy.

METHODS

We conducted a study of 508 cases identified among 1,264 patients with stage III colon cancer who enrolled in a randomized adjuvant chemotherapy trial (5-fluorouracil, leucovorin with or without irinotecan) in 1999-2001 (CALGB 89803). KRAS mutations were detected in 178 tumors (35%) by pyrosequencing. Kaplan-Meier and Cox proportional hazard models assessed the prognostic significance of KRAS mutation and adjusted for potential confounders including age, sex, tumor location, tumor/node stage, performance status, adjuvant chemotherapy arm, and microsatellite instability status.

RESULTS

Compared with patients with KRAS-wild-type tumors, patients with KRAS-mutated tumors did not experience any difference in disease-free, recurrence-free, or overall survival. The 5-year disease-free, recurrence-free, and overall survival rates (KRAS-mutated versus KRAS-wild-type patients) were 62% versus 63% (log-rank P = 0.89), 64% versus 66% (P = 0.84), and 75% versus 73% (P = 0.56), respectively. The effect of KRAS mutation on patient survival did not significantly differ according to clinical features, chemotherapy arm, or microsatellite instability status, and the effect of adjuvant chemotherapy assignment on outcome did not differ according to KRAS status.

CONCLUSIONS

In this large trial of chemotherapy in stage III colon cancer patients, KRAS mutational status was not associated with any significant influence on disease-free or overall survival.

OBJECTIVE

Standard treatments for neoplastic meningitis are only modestly effective and are associated with significant morbidity. Isolated reports suggest that concurrent systemic and intrathecal (i.t.) therapy may be more effective than i.t. therapy alone. We present our experience, which includes CSF and serum pharmacokinetic data, on the use of high-dose (HD) intravenous (i.v.) methotrexate (MTX) as the sole treatment for neoplastic meningitis.

METHODS

Sixteen patients with solid-tumor neoplastic meningitis received one to four courses (mean, 2.3 courses) of HD (8 g/m2 over 4 hours) i.v. MTX and leucovorin rescue. Serum and CSF MTX concentrations were measured daily. Toxicity, response, and survival were retrospectively compared with a reference group of 15 patients treated with standard i.t. MTX during the same time interval.

RESULTS

Peak methotrexate concentrations ranged from 3.7 to 55 micromol/L (mean, 17.1 micromol/L) in CSF and 178 to 1,700 micromol/L (mean, 779 micromol/L) in serum. Cytotoxic CSF and serum MTX concentrations were maintained much longer than with i.t. dosing. Toxicity was minimal. Cytologic clearing was seen in 81% of patients compared with 60% of patients treated intrathecally (P = .3). Median survival in the HD i.v. MTX group was 13.8 months versus 2.3 months in the i.t. MTX group (P = .003).

CONCLUSIONS

HD i.v. MTX is easily administered and well tolerated. This regimen achieves prolonged cytotoxic serum MTX concentrations and CSF concentrations at least comparable to those achieved with standard i.t. therapy. Cytologic clearing and survival may be superior in patients treated with HD i.v. MTX. Prospective studies and a reconsideration of the use of i.t. chemotherapy for patients with neoplastic meningitis are warranted.

Herein we present a historical review of the development of systemic chemotherapy for colorectal cancer (CRC) in the metastatic and adjuvant treatment settings. We describe the discovery of 5-fluorouracil (5-FU) by Heidelberger and colleagues in 1957, the potentiation of 5-FU cytotoxicity by the reduced folate leucovorin, and the advent of novel cytotoxic agents, including the topoisomerase I inhibitor irinotecan, the platinum-containing agent oxaliplatin, and the 5-FU prodrug capecitabine. The combination therapies, FOLFOX (5-FU/leucovorin and oxaliplatin) and FOLFIRI (5-FU/leucovorin and irinotecan), have become established as efficacious cytotoxic regimens for the treatment of metastatic CRC, resulting in overall survival times of approximately 2 years. When used as adjuvant therapy, FOLFOX also improves survival and is now the gold standard of care in this setting. Biological agents have been discovered that enhance the effect of cytotoxic therapy, including bevacizumab (a humanized monoclonal antibody that targets vascular endothelial growth factor, a central regulator of angiogenesis) and cetuximab/panitumumab (monoclonal antibodies directed against the epidermal growth factor receptor). Despite the ongoing development of novel antitumor agents and therapeutic principles as we enter the era of personalized cancer medicine, systemic chemotherapy involving infusional 5-FU/leucovorin continues to be the cornerstone of treatment for patients with CRC.

BACKGROUND

Treatment of advanced colorectal cancer has progressed substantially. However, improvements in response rates have not always translated into significant survival benefits. Doubts have therefore been raised about the usefulness of tumour response as a clinical endpoint.

METHODS

This meta-analysis was done on individual data from 3791 patients enrolled in 25 randomised trials of first-line treatment with standard bolus intravenous fluoropyrimidines versus experimental treatments (fluorouracil plus leucovorin, fluorouracil plus methotrexate, fluorouracil continuous infusion, or hepatic-arterial infusion of floxuridine). Analyses were by intention to treat.

RESULTS

Compared with bolus fluoropyrimidines, experimental fluoropyrimidines led to significantly higher tumour response rates (454 responses among 2031 patients vs 209 among 1760; odds ratio 0.48 [95% CI 0.40-0.57], p<0.0001) and better survival (1808 deaths among 2031 vs 1580 among 1760; hazard ratio 0.90 [0.84-0.97], p=0.003). The survival benefits could be explained by the higher tumour response rates. However, a treatment that lowered the odds of failure to respond by 50% would be expected to decrease the odds of death by only 6%. In addition, less than half of the variability of the survival benefits in the 25 trials could be explained by the variability of the response benefits in these trials.

CONCLUSIONS

These analyses confirm that an increase in tumour response rate translates into an increase in overall survival for patients with advanced colorectal cancer. However, in the context of individual trials, knowledge that a treatment has benefits on tumour response does not allow accurate prediction of the ultimate benefit on survival.

OBJECTIVE

This article reports the pharmacokinetics (PK) of heated intra-operative intraperitoneal oxaliplatin and its tolerance profile. Oxaliplatin has demonstrated significant activity in advanced colorectal cancer, and this is the first publication concerning its intraperitoneal administration.

METHODS

Twenty consecutive patients with peritoneal carcinomatosis (PC) of either gastrointestinal or uniquely peritoneal origin underwent complete cytoreductive surgery followed by intra-operative intraperitoneal chemo-hyperthermia (IPCH) with increasing doses of oxaliplatin. We performed IPCH using an open procedure (skin pulled upwards), at an intraperitoneal temperature of 42-44 degrees C, with 2 l/m2 of 5% dextrose instillate in a closed circuit. The flow-rate was 2 l/min for 30 min. Patients received intravenous leucovorin (20 mg/m2) and 5-fluorouracil (400 mg/m2) just before the IPCH to maximize the effect of oxaliplatin. We treated at least three patients at each of the six intraperitoneal oxaliplatin dose levels (from 260 to 460 mg/m2) before progressing to the next. We analysed intraperitoneal, plasma and tissue samples with atomic absorption spectrophotometry.

RESULTS

The mean duration of the entire procedure was 8.4 +/- 2.7 h. Half the oxaliplatin dose was absorbed in 30 min at all dose levels. Area under the curve (AUC) and maximal plasma concentration (Cmax) increased with dose. At the highest dose level (460 mg/m2), peritoneal oxaliplatin concentration was 25-fold that in plasma. AUCs following intraperitoneal administration were consistently inferior to historical control AUCs after intravenous oxaliplatin (130 mg/m2). Intratumoral oxaliplatin penetration was high, similar to absorption at the peritoneal surface and 17.8-fold higher than that in non-bathed tissues. Increasing instillate volume to 2.5 l/m2 instead of 2 l/m2 dramatically decreased oxaliplatin concentration and absorption. There were no deaths, nor severe haematological, renal or neurological toxicity, but we observed two fistulas and three deep abscesses.

CONCLUSIONS

Heated intraperitoneal chemotherapy gives high peritoneal and tumour oxaliplatin concentrations with limited systemic absorption. We recommend an oxaliplatin dose of 460 mg/m2 in 2 l/m2 of 5% dextrose for intraperitoneal chemo-hyperthermia, at a temperature of 42-44 degrees C over 30 min. We may be able to improve these results by increasing the intraperitoneal perfusion duration or by modifying the instillate composition.

OBJECTIVE

The purpose of this study was to examine the prognostic and oxaliplatin predictive value of mismatch repair (MMR) status and common hot spot mutations, which we previously identified in stage II and III colon cancer.

METHODS

Mutations in BRAF, KRAS, NRAS, MET, and PIK3CA were profiled in 2,299 stage II and III colon tumors from National Surgical Adjuvant Breast and Bowel Project (NSABP) clinical trials C-07 (n = 1,836) and C-08 (n = 463) with Type Plex chemistry and mass spectrometry. C-07 tested the worth of adding oxaliplatin to 5-fluorouracil plus leucovorin, and C-08 tested the worth of adding bevacizumab to FOLFOX. Cox proportional hazard models were used to assess prognostic or oxaliplatin predictive value of mutations for tumor recurrence, overall survival (OS), and survival after recurrence (SAR).

RESULTS

BRAF mutations were associated with MMR-deficient tumors (P < 0.0001), poor OS [HR, 1.46; 95% confidence interval (CI), 1.20-1.79; P ≤ 0.0002], and poor SAR (HR, 2.31; 95% CI, 1.83-2.95; P < 0.0001). Mutations in KRAS, NRAS, MET, and PIK3CA were not associated with recurrence, OS, or SAR. MMR-deficient tumors were associated with an improved prognosis based on recurrence (HR, 0.48; 95% CI, 0.33-0.70; P < 0.0001). Mutations and MMR status were not predictive for oxaliplatin benefit.

CONCLUSIONS

This study shows that BRAF mutations profiled from stage II and III colon cancer tumors were associated with poor SAR and validates and explains, at least in part, previous observations associating it with poor OS. Profiling of all of these mutations is warranted for future clinical trials testing new targeted therapies that block relevant signaling pathways. Such clinical trials are under development at NSABP.

Seventy-four previously untreated patients with metastatic colorectal adenocarcinoma were prospectively randomized into one of three treatment regimens: (1) 5-fluorouracil (5-FU) 450 mg/m2 as an intravenous (IV) bolus daily for five days or toxicity, then 200 mg/m2 IV bolus every other day for six doses; (2) methotrexate (MTX) 50 mg/m2 in normal saline by IV infusion over four hours followed by an IV bolus of 5-FU 600 mg/m2. This was administered weekly for 4 weeks and then every 2 weeks. (3) Leucovorin 500 mg/m2 in a two-hour IV infusion of normal saline with 5-FU 600 mg/m2 as an IV bolus one hour after the Leucovorin began every week for 6 weeks. The combined complete and partial response rates in the three regimens were 11%, 5%, and 48%, respectively (P = .0009). The median duration of response in the 5-FU and Leucovorin regimen was 10 months. There was no statistically significant difference between the treatment regimens with respect to survival time (P = .6). Toxicity in the 5-FU and Leucovorin regimen was predominantly diarrhea (13 of 30 patients, 40%). In this regimen, eight of 13 patients (52%) who developed diarrhea not only required a dose reduction of 5-FU, but also hospitalization for IV hydration. The predominant toxicity in the 5-FU alone regimen and the 5-FU and MTX regimen was leukopenia. One drug-related death occurred in each regimen.

High-dose methotrexate (500 to 33,600 mg per square meter of body-surface area) with leucovorin rescue is a common component of therapy for acute lymphocytic leukemia. To increase understanding of the relation between the serum concentration and the effect of methotrexate, we conducted a randomized, prospective study of 108 children with "standard-risk" acute lymphocytic leukemia who were treated with 15 doses of methotrexate (1000 mg per square meter) that were infused over 24 hours. The median length of follow-up was 3.5 years from diagnosis for patients still in remission. Variability between patients in methotrexate clearance produced steady-state serum concentrations that ranged from 9.3 to 25.4 microM. Patients with median methotrexate concentrations of less than 16 microM (n = 59) had a lower probability of remaining in remission (P less than 0.05) than patients with concentrations of 16 microM or more (n = 49). Multivariate analyses indicated that patients with methotrexate concentrations of less than 16 microM were 3 times more likely to have any kind of relapse during therapy (P = 0.01) and 7 times more likely to have a hematologic relapse during therapy (P = 0.001). Stepwise Cox's regression identified leukemic-cell DNA content, methotrexate concentration, and hemoglobin as significant prognostic variables for hematologic relapse (P = 0.0005). We conclude that there is a concentration-effect relation for high-dose methotrexate in acute lymphocytic leukemia and that 1000 mg per square meter infused over a period of 24 hours may not be optimal for patients with relatively fast drug clearance.

The aim of this study was to determine the patient's preference for oral UFT/leucovorin (LV) or intravenous (i.v.) 5-fluorouracil (5-FU)/LV chemotherapy in metastatic colorectal cancer and to compare 5-FU exposure with these two treatment options. A total of 37 previously untreated patients with advanced colorectal cancer were randomised to start treatment with either oral UFT 300 mg/m2/day plus oral LV 90 mg/day for 28 days every 5 weeks or i.v. 5-FU 425 mg/m2/day plus LV 20 mg/m2/day for 5 days every 4 weeks. For the second treatment cycle, patients were crossed-over to the alternative treatment regimen. Prior to the first and after the second therapy cycle, patients were required to complete a therapy preference questionnaire (TPQ). The pharmacokinetics of 5-FU were determined by taking blood samples on days 8, 15 or 22 and 28 for UFT and on days 1 and 5 for i.v. 5-FU. 36 patients were eligible. 84% of the patients preferred oral UFT over i.v. 5-FU. After having experienced both treatment modalities, patients indicated taking the medication at home, less stomatitis and diarrhoea, and pill over injection as the most important reasons for their preference. The area under the plasma concentration curve (AUC) for 5-FU after UFT administration was 113 microM x min on day 8, 114 on day 15 and 98 on day 28; the peak levels (Cmax) were 1.2, 1.3 and 1.0 microM, respectively. The AUC for the 5-FU/LV courses was 3083 microM x min for day 1 and 3809 for day 5 (P=0.002). The Cmax was 170.1 and 196.2 microM (P=0.06) and the clearance 2.6 and 1.9 l/min, respectively (P=0.002). Patients with metastatic colorectal cancer clearly preferred oral over i.v. chemotherapy treatment. This choice was most importantly influenced by convenience and toxicity considerations. Although i.v. bolus 5-FU leads to higher peak 5-FU concentrations and AUC values compared with oral UFT, this pharmacokinetic advantage of i.v. 5-FU seems to translate mainly into higher toxicity as seen in large randomised studies comparing oral UFT/LV with i.v. 5-FU/LV. Oral UFT/LV compares favourably with i.v. 5-FU/LV in terms of toxicity and patient's preference and leads to prolonged 5-FU exposure, which is comparable to continuous i.v. 5-FU treatment.

CPT-11 (irinotecan) has shown activity in patients with advanced colorectal cancer resistant to leucovorin (LV) and 5-fluorouracil (5-FU). In this study, the simplified bimonthly LV-5-FU regimen was combined with CPT-11 (FOLFIRI) as third-line therapy for patients with advanced colorectal cancer. Continuous infusion of 5-FU was administered with disposable pumps as outpatient therapy. FOLFIRI consisted of CPT-11 180 mg/m2 as a 90-min infusion day 1; LV 400 mg/m2 as a 2-h infusion during CPT-11, immediately followed by 5-FU bolus 400 mg/m2 and 46-h continuous infusion of 2.4-3 g/m2 every 2 weeks. Among the 33 patients treated, 2 had partial responses for an overall response rate of 6%; 20 patients were stabilised (61%) and 11 had disease progression (33%). From the start of FOLFIRI, median progression-free survival was 18 weeks and median survival was 43 weeks. For the 242 cycles analysed, NCI-CTC toxicities grade 3-4 per patient were nausea 15%, diarrhoea 12% and neutropenia 15%. Overall, 10 patients (30%) experienced grade 3-4 toxicity. 7 patients (21%) had grade 2 alopecia. FOLFIRI generated activity and acceptable toxicity, in heavily pretreated patients, with limited diarrhoea, mostly asymptomatic neutropenia and manageable nausea and relatively uncommon alopecia. This regimen is suitable for studies in chemotherapy-naïve patients.

BACKGROUND

Patients with locally advanced rectal cancer who achieve a pathological complete response to neoadjuvant chemoradiation have an improved prognosis. The need for surgery in these patients has been questioned, but the proportion of patients achieving a pathological complete response is small. We aimed to assess whether adding cycles of mFOLFOX6 between chemoradiation and surgery increased the proportion of patients achieving a pathological complete response.

METHODS

We did a phase 2, non-randomised trial consisting of four sequential study groups of patients with stage II-III locally advanced rectal cancer at 17 institutions in the USA and Canada. All patients received chemoradiation (fluorouracil 225 mg/m(2) per day by continuous infusion throughout radiotherapy, and 45·0 Gy in 25 fractions, 5 days per week for 5 weeks, followed by a minimum boost of 5·4 Gy). Patients in group 1 had total mesorectal excision 6-8 weeks after chemoradiation. Patients in groups 2-4 received two, four, or six cycles of mFOLFOX6, respectively, between chemoradiation and total mesorectal excision. Each cycle of mFOLFOX6 consisted of racemic leucovorin 200 mg/m(2) or 400 mg/m(2), according to the discretion of the treating investigator, oxaliplatin 85 mg/m(2) in a 2-h infusion, bolus fluorouracil 400 mg/m(2) on day 1, and a 46-h infusion of fluorouracil 2400 mg/m(2). The primary endpoint was the proportion of patients who achieved a pathological complete response, analysed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00335816.

RESULTS

Between March 24, 2004, and Nov 16, 2012, 292 patients were registered, 259 of whom (60 in group 1, 67 in group 2, 67 in group 3, and 65 in group 4) met criteria for analysis. 11 (18%, 95% CI 10-30) of 60 patients in group 1, 17 (25%, 16-37) of 67 in group 2, 20 (30%, 19-42) of 67 in group 3, and 25 (38%, 27-51) of 65 in group 4 achieved a pathological complete response (p=0·0036). Study group was independently associated with pathological complete response (group 4 compared with group 1 odds ratio 3·49, 95% CI 1·39-8·75; p=0·011). In group 2, two (3%) of 67 patients had grade 3 adverse events associated with the neoadjuvant administration of mFOLFOX6 and one (1%) had a grade 4 adverse event; in group 3, 12 (18%) of 67 patients had grade 3 adverse events; in group 4, 18 (28%) of 65 patients had grade 3 adverse events and five (8%) had grade 4 adverse events. The most common grade 3 or higher adverse events associated with the neoadjuvant administration of mFOLFOX6 across groups 2-4 were neutropenia (five in group 3 and six in group 4) and lymphopenia (three in group 3 and four in group 4). Across all study groups, 25 grade 3 or worse surgery-related complications occurred (ten in group 1, five in group 2, three in group 3, and seven in group 4); the most common were pelvic abscesses (seven patients) and anastomotic leaks (seven patients).

CONCLUSIONS

Delivery of mFOLFOX6 after chemoradiation and before total mesorectal excision has the potential to increase the proportion of patients eligible for less invasive treatment strategies; this strategy is being tested in phase 3 clinical trials.

BACKGROUND

National Institutes of Health National Cancer Institute.