OBJECTIVE

The rationale for using adjuvant chemotherapy in colorectal cancer is to achieve better disease control and thus reduce the high rates of tumor recurrence and mortality in patients who undergo curative surgery. The current literature, including relevant abstracts, on clinical trials of fluorouracil (5-FU) in combination with high-dose leucovorin as adjuvant chemotherapy for colorectal cancer is reviewed. The intent is not to present new data, but to present the reader with a broad perspective and larger patient experience on which to base well-reasoned treatment decisions.

METHODS

Published clinical trials and abstracts presented at the 1996 American Society of Clinical Oncology (ASCO) meeting that assessed 5-FU in combination with high-dose leucovorin as adjuvant chemotherapy for colorectal cancer were surveyed. End points of interest were disease-free survival (DFS), overall survival, and toxicity.

RESULTS

In randomized trials that used high-dose leucovorin at doses that ranged from daily-times-five 200 mg/m2 to weekly 500 mg/m2 in combination with 5-FU, significant improvements in both DFS and overall survival were observed over surgery alone (control). In patients treated with high-dose leucovorin/5-FU, DFS rates ranged from 71% to 77% compared with control (58% to 64%). A similar trend was seen in overall survival, with a range of 75% to 84% compared with control (63% to 77%). Toxicities observed for high-dose leucovorin administered on a weekly or daily-times-five schedule were diarrhea, stomatitis, myelosuppression, and nausea.

CONCLUSIONS

Overall, the results of these randomized trials support the use of high-dose leucovorin/5-FU as adjuvant therapy for colorectal cancer. Longer follow-up studies are needed to compare the benefits of these different regimens in terms of survival and to characterize adverse effects, especially those that may not be immediately evident. Adjuvant therapy with high-dose leucovorin/5-FU is an effective regimen that is well tolerated by many patients with colorectal cancer.

BACKGROUND

Somatic mutations in PIK3CA (phosphatidylinositol-4,5-bisphosphonate 3-kinase [PI3K], catalytic subunit alpha gene) activate the PI3K-AKT signaling pathway and contribute to pathogenesis of various malignancies, including colorectal cancer.

METHODS

We examined associations of PIK3CA oncogene mutation with relapse, survival, and treatment efficacy in 627 stage III colon carcinoma case subjects within a randomized adjuvant chemotherapy trial (5-fluorouracil and leucovorin [FU/LV] vs irinotecan [CPT11], fluorouracil and leucovorin [IFL]; Cancer and Leukemia Group B 89803 [Alliance]). We detected PIK3CA mutation in exons 9 and 20 by polymerase chain reaction and pyrosequencing. Cox proportional hazards model was used to assess prognostic and predictive role of PIK3CA mutation, adjusting for clinical features and status of routine standard molecular pathology features, including KRAS and BRAF mutations and microsatellite instability (mismatch repair deficiency). All statistical tests were two-sided.

RESULTS

Compared with PIK3CA wild-type cases, overall status of PIK3CA mutation positivity or the presence of PIK3CA mutation in either exon 9 or 20 alone was not statistically significantly associated with recurrence-free, disease-free, or overall survival (log-rank P>> .70; P>> .40 in multivariable regression models). There was no statistically significant interaction between PIK3CA and KRAS (or BRAF) mutation status in survival analysis (P(interaction)>> .18). PIK3CA mutation status did not appear to predict better or worse response to IFL therapy compared with FU/LV therapy (P(interaction)>> .16).

CONCLUSIONS

Overall tumor PIK3CA mutation status is not associated with stage III colon cancer prognosis. PIK3CA mutation does not appear to serve as a predictive tumor molecular biomarker for response to irinotecan-based adjuvant chemotherapy.

BACKGROUND

The high recurrence rate after surgery for colorectal cancer liver metastasis (CLM) remains a crucial problem. The aim of this trial was to evaluate the efficacy of adjuvant therapy with uracil-tegafur and leucovorin (UFT/LV).

METHODS

In the multicenter, open-label, phase III trial, patients undergoing curative resection of CLM were randomly assigned in a 1:1 ratio to either the UFT/LV group or surgery alone group. The UFT/LV group orally received 5 cycles of adjuvant UFT/LV (UFT 300mg/m2 and LV 75mg/day for 28 days followed by a 7-day rest per cycle). The primary endpoint was recurrence-free survival (RFS). Secondary endpoints included overall survival (OS).

RESULTS

Between February 2004 and December 2010, 180 patients (90 in each group) were enrolled into the study. Of these, 3 patients (2 in the UFT/LV group and 1 in the surgery alone group) were excluded from the efficacy analysis. Median follow-up was 4.76 (range, 0.15-9.84) years. The RFS rate at 3 years was higher in the UFT/LV group (38.6%, n = 88) than in the surgery alone group (32.3%, n = 89). The median RFS in the UFT/LV and surgery alone groups were 1.45 years and 0.70 years, respectively. UFT/LV significantly prolonged the RFS compared with surgery alone with the hazard ratio of 0.56 (95% confidence interval, 0.38-0.83; P = 0.003). The hazard ratio for death of the UFT/LV group against the surgery alone group was not significant (0.80; 95% confidence interval, 0.48-1.35; P = 0.409).

CONCLUSIONS

Adjuvant therapy with UFT/LV effectively prolongs RFS after hepatic resection for CLM and can be recommended as an alternative choice.

BACKGROUND

UMIN Clinical Trials Registry C000000013.

BACKGROUND

This study evaluated the effectiveness and safety of preoperative chemoradiotherapy with capecitabine in patients with locally advanced resectable rectal cancer. This report summarizes the results of the phase II study together with long-term (5-year) follow-up.

METHODS

Between June 2004 and January 2005, 57 patients with operable, clinical stage II-III adenocarcinoma of the rectum entered the study. Radiation dose was 45 Gy delivered as 25 fractions of 1.8 Gy. Concurrent chemotherapy with oral capecitabine 825 mg/m² twice daily was administered during radiotherapy and at weekends. Surgery was scheduled 6 weeks after the completion of the chemoradiotherapy. Patients received four cycles of postoperative chemotherapy comprising either capecitabine 1250 mg/m² bid days 1-14 every 3 weeks or bolus i.v. 5-fluorouracil 425 mg/m²/day and leucovorin 20 mg/m²/day days 1-5 every 4 weeks (choice was at the oncologist's discretion). Study endpoints included complete pathological remission, proportion of R0 resections and sphincter-sparing procedures, toxicity, survival parameters and long-term (5-year) rectal and urogenital morbidity assessment.

RESULTS

One patient died after receiving 27 Gy because of a pulmonary embolism. Fifty-six patients completed radiochemotherapy and had surgery. Median follow-up time was 62 months. No patients were lost to follow-up. R0 resection was achieved in 55 patients. A complete pathological response was observed in 5 patients (9.1%); T-, N- and overall downstaging rates were 40%, 52.9% and 49.1%, respectively. The 5-year overall survival rate, recurrence-free survival, and local control was 61.4% (95% CI: 48.9-73.9%), 52.4% (95% CI: 39.3-65.5%), and 87.4% (95% CI: 75.0-99.8%), respectively. In 5 patients local relapse has occurred; dissemination was observed in 19 patients and secondary malignancies have occurred in 2 patients. The most frequent side-effect of the preoperative combined therapy was dermatitis (grade 3 in 19 patients). The proportion of patients with severe late (SOMA grade 3 and 4) rectal, bladder and sexual toxicity was 40%, 19.2% and 51.7%, respectively.

CONCLUSIONS

This study confirms data from other non-randomised studies that capecitabine-based preoperative chemoradiation is a feasible treatment option for locally advanced rectal cancer, with positive 5-year overall survival, recurrence-free survival, and local control rates.

BACKGROUND

Our current protocol for treatment of childhood acute lymphoblastic leukemia (ALL) was designed to assess the efficacy of methotrexate (MTX) plus L-asparaginase and of etopisode (VP-16) plus cytarabine (ARA-C) during intensive consolidation and continuation therapies and to determine the feasibility of intensifying MTX therapy by the use of divided oral doses of MTX. The protocol was associated with unexpected acute neurotoxicity. There are few reports of such toxic effects during therapy for ALL.

OBJECTIVE

This report describes these toxic effects and outlines our successful approach to the problem.

METHODS

The standard four-drug induction regimen consisted of vincristine, L-asparaginase, daunorubicin, and prednisone. In consolidation therapy, oral MTX was given in divided doses (dMTX) of 25 mg/m2 every 6 hours four times daily in four weekly courses concomitant with weekly triple intrathecal therapy--MTX, ARA-C, and hydrocortisone--plus one dose of leucovorin 24 hours after triple intrathecal therapy. Consolidation treatment ended with three daily doses of intravenous VP-16 and ARA-C. The first 16 months of continuation therapy included 6-week cycles of dMTX and L-asparaginase, both given every other week for 5 weeks, with 6-mercaptopurine nightly, and then two doses of VP-16 plus ARA-C and one dose of triple intrathecal therapy.

RESULTS

Twenty-five of the 138 patients evaluated had acute neurotoxicity. Ten of the first 72 experienced a seizure or episode of transient neurological deficit 9-11 days following the administration of intravenous ARA-C, VP-16, and triple intrathecal therapy. Despite discontinuation of intrathecal ARA-C, which eliminated simultaneous intravenous and intrathecal treatment with ARA-C, acute neurotoxicity was observed in six previously unaffected patients and six of 42 patients treated after the elimination of intrathecal ARA-C. Therefore, as a second amendment, oral leucovorin was given 24 and 36 hours after dMTX and intrathecal MTX in continuation therapy. No acute neurotoxicity has been seen in 24 patients subsequently entered in the study.

CONCLUSIONS

These findings suggest that folate replacement due to administration of leucovorin modulated MTX toxicity and/or modified an interaction among VP-16, ARA-C, intrathecal therapy, and the central nervous system.

Chemotherapy for treatment of osteosarcoma was demonstrated to be effective in eradicating primary tumor and pulmonary metastases in the mid-twentieth century. The first agents that held promise were doxorubicin and high-dose methotrexate with leucovorin (citrovorin factor) in the mid-1970s. Since then, other agents that can eliminate or cause regression of tumor have been discovered: cis-diamminedichloroplatinum II (cisplatin) and the oxazaphosphorines ifosfamide and cyclophosphamide. Additional agents await further study to define their potential. The effective agents have been utilized in various combination regimens and have escalated the survival rate from <10 to 75 %. They have also enabled pulmonary metastectomy in patients with persistent and/or recurrent pulmonary metastases and tumor ablation and limb salvage in 80 % of newly diagnosed patients. Unfortunately, however, despite these impressive advances no change in survival expectancy of patients with osteosarcoma during the past 40 years has occurred. There have been no new chemotherapeutic agents effective in addressing disease that is resistant to current agents; the few that have been introduced await further study to substantiate their efficacy. This also includes attempts at alternate administration of chemotherapy (intra-arterial and inhalation therapy.) In this chapter, we provide an account of the sequential introduction of the chemotherapeutic agents, review the results of their application in selected regimens, and discuss the role of neoadjuvant chemotherapy.

Bevacizumab is an anti-VEGF human monoclonal antibody suitable for chemotherapy for patients with metastatic colorectal cancer (mCRC). This study investigated the efficacy and safety of using bevacizumab plus irinotecan, 5-fluorouracil, and leucovorin (FOLFIRI) as second-line chemotherapy option for patients with mCRC in China. Patients with mCRC, who had been previously treated with oxaliplatin-based chemotherapy, but not bevacizumab, were randomly assigned to two groups to receive bevacizumab plus FOLFIRI (FOLFIRI-B) or FOLFIRI alone. In FOLFIRI-B group, patients were given 10 mg/kg bevacizumab plus FOLFIRI every 2 weeks. The primary endpoints were response rates and survival rates. Between June 2010 and May 2014, 65 patients were assigned to FOLFIRI-B group and 77 to FOLFIRI alone group. The median progression-free survivals were 8.5 months (95 % CI 5.8-10.5 months) for FOLFIRI-B and 5.1 months (95 % CI 2.7-9.8 months) for FOLFIRI alone; median overall survivals were 15.2 months (95 % CI 11.8-19.4 months) for FOLFIRI-B and 11.3 months (95 % CI 6.7-16.5 months) for FOLFIRI alone. Incidence rates of grade 3 and 4 adverse events were observed and comparable between FOLFIRI-B and FOLFIRI alone groups. Chinese patients with mCRC treated with second-line chemotherapy of FOLFIRI-B had better survivals than those patients treated with FOLFIRI alone.

OBJECTIVE

To investigate the sequence effect of irinotecan and a 48-hour infusion of fluorouracil (5-FU) modulated by leucovorin (LV) on the plasma pharmacokinetics of irinotecan and its metabolites, the toxicity profile of this combination, and irinotecan's maximum-tolerated dose (MTD).

METHODS

Thirty-three metastatic colorectal cancer patients were randomized to receive a 60-minute infusion of irinotecan before or after a 48-hour infusion of 5-FU modulated by LV. The reverse sequence was used after 21 days for the second cycle. 5-FU 3,500 mg/m2 was preceded by l-LV 250 mg/m2. Irinotecan 150 mg/m2 (starting dose) was administered to the first three patients. The dose was escalated by 50 mg/m2 in subsequent groups of three to six patients to determine the MTD for both sequences. Pharmacokinetic analysis of irinotecan and its metabolites was performed after each cycle.

RESULTS

Toxicities were affected by the sequence of administration of irinotecan and 5-FU, with an improved tolerability for irinotecan followed by 5-FU. The irinotecan MTD was reached at 300 mg/m2 when irinotecan followed 5-FU and at 450 mg/m2 when it preceded 5-FU. In seven of 23 patients who received both sequences at identical irinotecan doses, the dose-limiting toxicity was observed only when irinotecan followed 5-FU. Pharmacokinetic analysis revealed that the administration sequence significantly affected the SN-38 area under the concentration-versus-time curve (AUC), which was 40.1% lower (P <.05) when irinotecan preceded 5-FU.

CONCLUSIONS

The sequence of treatment with irinotecan and infusional 5-FU affects the tolerability of this combination. This can be explained in part by a reduced SN-38 AUC when irinotecan preceded infusional 5-FU. Well-defined 5-FU/irinotecan regimens are needed because the administration sequence or the interval between the agents might affect treatment tolerance and perhaps also activity.

Colorectal cancer (CRC) is a highly prevalent malignant disease in industrialized nations. The annual incidence of invasive CRC in the U.S. is among the highest in the world, and the liver is the only metastatic site in approximately one third of patients. Without treatment, patients with metastatic disease have a poor prognosis; however, long-term survival benefits and even cure have been reported in patients undergoing surgical resection of metastases. In addition, advances in chemotherapy, imaging, and surgical techniques have increased the proportion of patients who are eligible for resection. Combination therapy with fluorouracil and leucovorin has been the mainstay of treatment for metastatic CRC; however, the introduction of newer agents, such as oxaliplatin and irinotecan, and targeted agents, such as cetuximab and bevacizumab, has yielded improvements in response rates (RRs) and survival. Maximizing the exposure of hepatic metastases to high target concentrations of cytotoxic drugs using hepatic arterial infusion (HAI) increases RRs further than with systemic chemotherapy; however, the impact of HAI on survival is unclear. As the goals of chemotherapeutic treatment for metastatic CRC increasingly shift from palliation to prolongation of survival, improvement in RRs, and downsizing of tumors in order to enable or optimize resection, treatment in a multidisciplinary environment involving a medical oncologist, radiologist, and surgical oncologist with hepatobiliary expertise will become central to deciding the best course of therapy and timing of surgery.

Pancreatic adenocarcinoma (PDAC) is one of the most deadly cancers because of a lack of early diagnostic markers and efficient therapeutics. The fluorinated analog of deoxycytidine, gemcitabine and emerging FOLFIRINOX protocol (5-fluorouracil (5-FU), irinotecan/SN-38, oxaliplatin and leucovorin) are the main chemotherapies to treat PDAC. The ErbB2/HER2 oncogenic receptor is commonly overexpressed in PDAC. In this context, we aimed to decipher the ErbB2-mediated mechanisms of chemoresistance to the two main chemotherapy protocols used to treat PDAC.ErbB2 knocking down (KD) in CAPAN-1 and CAPAN-2 cells led to an increased sensitivity to gemcitabine and an increased resistance to irinotecan/SN-38 both in vitro and in vivo (subcutaneous xenografts) This was correlated to an increase of hCNT1 and hCNT3 transporters and ABCG2, MRP1 and MRP2 ATP-binding cassette transporters expression and resistance to cell death. We also show that MRP2 is repressed following activation of JNK, Erk1/2 and NF-κB pathways by ErbB2. Finally, in datasets of human PDAC samples, ErbB2 and MRP2 expression was conversely correlated. Altogether, we propose that ErbB2 mediates several intracellular mechanisms linked to PDAC cell chemoresistance that may represent potential targets in order to ameliorate chemotherapy response and allow stratification of patients eligible for either gemcitabine or FOLFIRINOX treatment.

BACKGROUND

The impact of bevacizumab on functional recovery and histology of the liver was evaluated in patients undergoing hepatic resection for colorectal liver metastases (CLM) following bevacizumab treatment.

METHODS

Consecutive patients who had resection of CLM between July 2005 and July 2009 following preoperative chemotherapy were identified retrospectively from a prospectively collected database. Patients who had received bevacizumab before the last chemotherapy line were excluded. Postoperative liver function and histology were compared between patients with and without bevacizumab treatment. Recorded parameters included serum prothrombin time, total bilirubin concentration, and levels of aspartate and alanine aminotransferase and γ-glutamyltransferase.

RESULTS

Of 208 patients identified, 67 had received last-line bevacizumab, 44 were excluded and 97 had not received bevacizumab. Most patients in the bevacizumab group (66 per cent) received a single line of chemotherapy. Bevacizumab was most often combined with 5-flurouracil/leucovorin and irinotecan (68 per cent). The median number of bevacizumab cycles was 8·6 (range 1-34). Bevacizumab administration was stopped a median of 8 (range 3-19) weeks before surgery. There were no deaths. Postoperative morbidity occurred in 43 and 36 per cent of patients in the bevacizumab and no-bevacizumab groups respectively (P = 0·353). The mean(s.d.) degree of tumour necrosis was significantly higher in the bevacizumab group (55(27) versus 32(29) per cent; P = 0·001). Complete pathological response rates were comparable (3 versus 8 per cent; P = 0·307). Postoperative changes in functional parameters and objective signs of hepatic toxicity were similar in both groups.

CONCLUSIONS

Preoperative administration of bevacizumab does not seem to affect functional recovery of the liver after resection of CLM. Tumour necrosis is increased following bevacizumab treatment.

BACKGROUND

Borderline resectable pancreatic cancers infiltrate into adjacent vascular structures to an extent that makes an R0 resection unlikely when pancreatectomy is performed de novo. In a pilot study, Alliance for Clinical Trials in Oncology Trial A021101, the median survival of patients who received chemotherapy and radiation prior to anticipated pancreatectomy was 22 months, and 64% of operations achieved an R0 resection. However, the individual contributions of preoperative chemotherapy and radiation therapy to therapeutic outcome remain poorly defined.

METHODS

In Alliance for Clinical Oncology Trial A021501, a recently activated randomized phase II trial, patients (N = 134) with a CT or MRI showing a biopsy-confirmed pancreatic ductal adenocarcinoma that meets centrally-reviewed anatomic criteria for borderline resectable disease will be randomized to receive either 8 cycles of modified FOLFIRINOX (oxaliplatin 85 mg/m2, irinotecan 180 mg/m2, leucovorin 400 mg/m2 and infusional 5-fluorouracil 2400 mg/m2 over 2 days for 4 cycles) or to 7 cycles of modified FOLFIRINOX followed by stereotactic body radiation therapy (33-40 Gy in 5 fractions). Patients without evidence of disease progression following preoperative therapy will undergo pancreatectomy and will subsequently receive 4 cycles of postoperative modified FOLFOX6 (oxaliplatin 85 mg/m2, leucovorin 400 mg/m2, bolus 5-fluorouracil 400 mg/m2, and infusional 5-fluorouracil 2400 mg/m2 over 2 days for 4 cycles). The primary endpoint is the 18-month overall survival rate of patients enrolled into each of the two treatment arms. An interim analysis of the R0 resection rate within each arm will be conducted to assess treatment futility after accrual of 30 patients. Secondary endpoints include rates of margin-negative resection and event-free survival. The primary analysis will compare the 18-month overall survival rate of each arm to a historical control rate of 50%. The trial is activated nationwide and eligible to be opened for accrual at any National Clinical Trials Network cooperative group member site.

CONCLUSIONS

This study will help define standard preoperative treatment regimens for borderline resectable pancreatic cancer and position the superior arm for further evaluation in future phase III trials.

BACKGROUND

ClinicalTrials.gov : NCT02839343 , registered July 14, 2016.

The safety profile in the patient groups who received FOLFIRI and simtuzumab did not differ from that in the FOLFIRI and placebo group.The addition of simtuzumab to chemotherapy with FOLFIRI does not improve clinical outcomes in patients with metastatic KRAS mutant colorectal carcinoma.

Simtuzumab, a humanized IgG4 monoclonal antibody to lysyl oxidase-like 2 (LOXL2), blocks desmoplastic reaction in colorectal carcinoma (CRC) cells in vitro.

Patients with metastatic Kirsten rat sarcoma viral oncogene homolog (KRAS) mutant CRC were randomized to receive second-line 5-fluorouracil, leucovorin, and irinotecan (FOLFIRI) with either 200 or 700 mg simtuzumab or placebo every 2 weeks in cycles of 28 days. Progression-free survival (PFS), overall survival (OS), objective response rate (ORR), and safety were assessed.

In total, 249 patients were randomized and treated with FOLFIRI/simtuzumab 700 mg (n = 84), FOLFIRI/simtuzumab 200 mg (n = 85), and FOLFIRI/placebo (n = 80). After a median follow-up of 5.1, 3.8, and 5.5 months, respectively, median PFS for each of the respective treatment groups was 5.5 months (adjusted HR [95% CI], p value versus placebo; 1.32 [0.92, 1.89]; p = .10), 5.4 months (1.45 [1.01, 2.06]; p = .04), and 5.8 months. Median OS was 11.4 months (1.23 [0.80, 1.91]; p = .25), 10.5 months (1.50 [0.98, 2.30]; p = .06), and 16.3 months, respectively. ORR was 11.9%, 5.9%, and 10%, respectively. Simtuzumab was tolerable in metastatic KRAS mutant CRC patients.

The addition of simtuzumab to FOLFIRI did not improve clinical outcomes in patients with metastatic KRAS mutant CRC. The Oncologist 2017;22:243-e8.

OBJECTIVE

Human DNA topoisomerases I and II (topo-I and -II) are essential for vital cellular processes such as DNA replication, transcription, translation, recombination, and repair. In the present study, we correlate topo-I and -II expression and outcome after chemotherapy in primary and relapsed colorectal cancer.

METHODS

Patients with colorectal cancer that had recurred, following surgery and adjuvant chemotherapy and underwent a second operation were included in the present study. All had undergone surgical resection of the primary tumor and received post-operatively 5-FU-based (5FU + Leucovorin, Mayo Clinic regimen) adjuvant chemotherapy. Tumor tissue was collected at the initial operation from the primary tumor and at the time of recurrence (during the second operation following chemotherapy). All tissue samples were analyzed for levels of expression of both topo-I and topo-IIa using standard three-step immunohistochemistry on paraffin sections.

RESULTS

Forty patients were included. Levels of expression of topo-I and topo-II were higher in malignant cells from tumor recurrences compared to primary tumors (P = 0.0001 for both). There was a statistically significant positive relationship between patients age and levels of topo-I (P = 0.011) and topo-II (P = 0.011) expression.

CONCLUSIONS

The study results reported here underscore the role of topoisomerase expression in colorectal cancer and suggest a potential role in tumor recurrence.

OBJECTIVE

To characterize the population pharmacokinetics of bevacizumab, its binding properties to VEGF165 and the effect of demographic data and VEGF-A polymorphisms on the interplay between bevacizumab serum pharmacokinetics and VEGF165 serum concentrations in patients with colorectal cancer stage IV.

METHODS

Bevacizumab and VEGF165 data were collected from 19 adult patients with metastatic colorectal cancer enrolled in an observational clinical study. Bevacizumab was administered with one of the following combinations: 5-FU/Leucovorin/Irinotecan, 5-FU/Leucovorin/Oxaliplatin, Capecitabine/Irinotecan at doses ranging from 5 to 10 mg/kg every 2 or 3 weeks. Data analysis was performed using nonlinear mixed-effects modeling implemented in NONMEM 7.3.

RESULTS

A target-mediated drug disposition model adequately described bevacizumab concentration changes over time and its binding characteristics to VEGF165. The estimated clearance of bevacizumab was 0.18 L/day, the free VEGF165 levels at baseline were 212 ng/L, and the elimination rate constant of free VEGF165 was 0.401 day(-1). Body weight was allometrically included in all PK parameters.

CONCLUSIONS

The final model adequately described the pre- and post-dose concentrations of total bevacizumab and free VEGF165 in patients with colorectal cancer. Model parameters were consistent with those previously reported for patients with solid tumors. Correlations between the binding affinity of bevacizumab and the VEGF-2578C/A and VEGF-634G/C polymorphisms were noticed.

The purpose of the study was to examine inter- and intrapatient variation in 5-fluorouracil (5-FU) plasma concentrations in adult cancer patients receiving a 3-day drug infusion. Fourteen patients received 1266 mg/m2 N-(phosphonacetyl)-L-aspartate (PALA) infused i.v. over 15 min on day 1, followed immediately by a loading dose of 500 mg/m2 calcium leucovorin over 30 min. Then a prolonged infusion of leucovorin at 500 mg/m2/day and 5-FU at 1750 mg/m2/day was administered as either a constant rate or as a circadian infusion over 72 h. During constant rate infusions, 5-FU concentrations within individuals varied by 1.7-fold, but no uniform time of peak or trough concentration was observed. Transformation of these data by setting the time of peak to 0 h and by expressing concentrations as the percentage of the 24-h mean value revealed a nonrandom distribution of the time from peak to trough with a median time of 12 h (P = 0.027). These transformed data were also successfully fit to a circadian cosinor function (P < 0.001). During multiple constant rate 5-FU infusions, the intrapatient variability was high; the times of peak 5-FU concentration occurred at the same approximate sampling time 43% of the time, and troughs coincided 17% of the time. No difference in clinical toxicity was observed when matched constant rate and circadian infusions of 5-FU were compared. High inter- and intrapatient variability exists in 5-FU plasma concentrations in adult cancer patients during constant rate infusions with no evidence of a consistent circadian rhythm in untransformed data.

OBJECTIVE

To determine if simultaneously administered low dose leucovorin interferes with the efficacy of methotrexate (MTX).

METHODS

An 8-week double blind placebo controlled study of leucovorin (1 mg) in 16 patients with rheumatoid arthritis receiving chronic MTX was performed at a single academic center.

RESULTS

A flare of disease activity was not observed. Clinical variables of arthritis activity did not change in the leucovorin treated population.

CONCLUSIONS

Low dose leucovorin when taken simultaneously with MTX did not interfere with the efficacy of MTX in a short term 8 week trial.

BACKGROUND

This open-label, phase IB study was undertaken to determine the safety/toxicity profile and recommended dose of oral once-daily PTK787/ZK 222584 (PTK/ZK) combined with oxaliplatin/5-fluorouracil (5-FU)/leucovorin (FOLFOX4) chemotherapy in patients with advanced colorectal cancer. Secondary objectives were to assess full pharmacokinetics and gather preliminary evidence of antitumor activity.

METHODS

Thirty-five patients received escalating doses of PTK/ZK (range 500-2000 mg daily) continuously. Concurrent FOLFOX4 chemotherapy was administered on days 1 and 2 and repeated every 14 days. Dose escalation of PTK/ZK was continued until maximum tolerated dose (MTD) was established and additional patients were then enrolled at MTD dosage.

RESULTS

Mean treatment duration of PTK/ZK was 9.5 months. The MTD was 1250 mg daily with dizziness being the most frequent dose-limiting toxicity (DLT). Hypertension (23%, grade 3) and neutropenia (37%, grades 3 + 4) were the most frequent grade 3 or 4 adverse events. Pharmacokinetic analyses found no evidence for interactions between PTK/ZK and the combination of 5-FU, leucovorin, and oxaliplatin during concomitant use. Median progression-free survival was 11.4 months.

CONCLUSIONS

The MTD of PTK/ZK in combination with FOLFOX4 in this patient population is 1250 mg daily. The combination is feasible and safe and is not associated with significant pharmacokinetic interactions.

OBJECTIVE

To evaluate, in a prospective multicentric study, the efficacy of a conventional salvage chemotherapy (dexamethasone, cisplatin, and cytarabine [DHAP]) versus high-dose chemotherapy (carmustine, etoposide, cytarabine, and cyclophosphamide [BEAC]) followed by autologous bone marrow transplantation (ABMT) in patients with aggressive non-Hodgkin's lymphoma (NHL) in clinical partial response (PR) after two thirds of a conventional front-line therapy.

METHODS

From August 1988 to August 1991, 286 patients with aggressive NHL were randomized in seven Italian institutions to receive fluorouracil, methotrexate, cytarabine, cyclophosphamide, doxorubicin, vincristine, and prednisone (F-MACHOP) or methotrexate with leucovorin, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin (MACOP-B) as front-line therapy. Of the 286 patients enrolled onto the trial, 77 (27%) were considered in PR after two thirds of the front-line therapy, and 49 of 77 (64%) were randomized: 27 to receive DHAP chemotherapy and 22 to receive BEAC followed by ABMT.

RESULTS

The response after second-line treatment was as follows: in the DHAP group, four patients (15%) achieved a complete remission (CR), 12 (44%) remained in stable PR, and 11 (41%) showed progressive disease; in the ABMT group, three patients (14%) obtained a CR, 18 (82%) obtained a stable PR, and one (4%) progressed, with an overall response (CR + stable PR) of 59% and 96% (P < .001) in the DHAP and ABMT groups, respectively. The overall survival was 59% versus 73% and the progression-free survival (PFS) was 52% versus 73% in the DHAP and ABMT groups, respectively (P, not significant). The toxicity was mild, particularly in the ABMT group, and no treatment-related deaths occurred in either group.

CONCLUSIONS

Because of the small number of patients randomized, we were unable to determine whether ABMT or a standard salvage regimen (DHAP) is superior for PR patients. However, we confirmed that myeloablative treatment is a safe and well-tolerated procedure in this category of patients and this may enable us to evaluate its role as part of a front-line treatment in poor-risk NHL patients.

We designed a phase II study to determine whether induction chemotherapy (CT) consisting of leucovorin, vincristine, methotrexate, doxorubicin, and cyclophosphamide (LOMAC) followed by high-dose intensification chemotherapy (ICT) with cyclophosphamide, thiotepa, and autologous stem cell rescue (ASCR) could increase the complete response (CR) rate and survival in women with stage IV breast cancer. Twenty-nine women were enrolled on study; 16 patients had received prior adjuvant chemotherapy and no patient had received chemotherapy for stage IV disease. Two patients were found to be ineligible and excluded from further analysis. Of the 27 patients treated, four (15%) obtained a CR and 15 (56%) a partial response (PR) after LOMAC induction, for an overall response rate of 70%. Of the 22 patients treated with ICT, 12 patients had a CR, and nine were in PR after induction and converted to CR after ICT. The toxicities included nausea/vomiting, mucositis, diarrhea, dermatitis, alopecia, and infections secondary to neutropenia. The 1-year survival is 60%; the median has not yet been reached. The time to treatment failure for patients on study is 10 months. The treatment approach of ICT and ASCR following induction chemotherapy can lead to an improved CR rate in stage IV breast cancer. How this increased CR rate leads to a prolonged disease-free survival requires further follow-up.

OBJECTIVE

By using data from North Central Cancer Treatment Group Phase III Trial N0147, a randomized adjuvant trial of patients with stage III colon cancer, we assessed the relationship between smoking and cancer outcomes, disease-free survival (DFS), and time to recurrence (TTR), accounting for heterogeneity by patient and tumor characteristics. PATIENTS AND METHODS Before random assignment to infusional fluorouracil, leucovorin, and oxaliplatin (FOLFOX) or FOLFOX plus cetuximab, 1,968 participants completed a questionnaire on smoking history and other risk factors. Cox models assessed the association between smoking history and the primary trial outcome of DFS (ie, time to recurrence or death), as well as TTR, adjusting for other clinical and patient factors. The median follow-up was 3.5 years among patients who did not experience events.

RESULTS

Compared with never-smokers, ever smokers experienced significantly shorter DFS (3-year DFS proportion: 70% v 74%; hazard ratio [HR], 1.21; 95% CI, 1.02 to 1.42). This association persisted after multivariate adjustment (HR, 1.23; 95% CI, 1.02 to 1.49). There was significant interaction in this association by BRAF mutation status (P = .03): smoking was associated with shorter DFS in patients with BRAF wild-type (HR, 1.36; 95% CI, 1.11 to 1.66) but not BRAF mutated (HR, 0.80; 95% CI, 0.50 to 1.29) colon cancer. Smoking was more strongly associated with poorer DFS in those with KRAS mutated versus KRAS wild-type colon cancer (HR, 1.50 [95% CI, 1.12 to 2.00] v HR, 1.09 [95% CI, 0.85 to 1.39]), although interaction by KRAS mutation status was not statistically significant (P = .07). Associations were comparable in analyses of TTR.

CONCLUSIONS

Overall, smoking was significantly associated with shorter DFS and TTR in patients with colon cancer. These adverse relationships were most evident in patients with BRAF wild-type or KRAS mutated colon cancer.

OBJECTIVE

FOLFOX (a combination of leucovorin, fluorouracil and oxaliplatin) has achieved substantial success in the treatment of colorectal cancer (CRC) patients. However, about half of all patients show resistance to this regimen and some develop adverse symptoms such as neurotoxicity. In order to select patients who would benefit most from this therapy, we aimed to build a predictor for the response to FOLFOX using microarray gene expression profiles of primary CRC samples.

METHODS

Forty patients who underwent surgery for primary lesions were examined. All patients had metastatic or recurrent CRC and received modified FOLFOX6. Responders and nonresponders were determined according to the best observed response at the end of the first-line treatment. Gene-expression profiles of primary CRC were determined using Human Genome GeneChip arrays U133. We identified discriminating genes whose expression differed significantly between responders and nonresponders and then carried out supervised class prediction using the k-nearest-neighbour method.

RESULTS

We identified 27 probes that were differentially expressed between responders and nonresponders at significant levels. Based on the expression of these genes, we constructed a FOLFOX response predictor with an overall accuracy of 92.5%. The sensitivity, specificity, positive and negative predictive values were 78.6%, 100%, 100% and 89.7%, respectively.

CONCLUSIONS

The present model suggests the possibility of selecting patients who would benefit from FOLFOX therapy both in the metastatic and the adjuvant setting. To our knowledge, this is the first study to establish a prediction model for the response to FOLFOX chemotherapy based on gene expression by microarray analysis.

A multimodality approach of moderate-dose to high-dose preoperative radiation therapy, surgical resection, and intraoperative electron beam radiation therapy (IORT) has been used for patients with locally recurrent rectal or rectosigmoid carcinoma. The 5-year actuarial local control and disease-free survival for 30 patients undergoing this treatment program were 26% and 19%, respectively. The most important factor predicting a favorable outcome was complete resection with negative pathologic resection margins. The determinant local control and disease-free survival for 13 patients undergoing complete resection were 62% and 54%, respectively, whereas for 17 patients undergoing partial resection these figures were 18% and 6%, respectively. There did not appear to be a difference in local control or survival based on the original surgical resection (abdominoperineal resection versus low anterior resection). However, the likelihood of obtaining a complete resection after preoperative radiation therapy was higher in patients who had previously undergone a low anterior resection than patients undergoing prior abdominoperineal resection. For the 30 patients undergoing external beam irradiation, resection, and IORT, the most significant toxicities were soft tissue or sacral injury and pelvic neuropathy. Efforts to further improve local control are directed toward the concurrent use of chemotherapy (5-fluorouracil with and without leucovorin) as radiation dose modifiers during external beam irradiation and the use of additional postoperative radiation therapy.

OBJECTIVE

Information in the literature regarding salvage treatment for patients with locally recurrent colorectal cancer who have previously been treated with high or moderate dose external beam irradiation (EBRT) is scarce. A retrospective review was therefore performed in our institution to determine disease control, survival, and tolerance in patients treated aggressively with surgical resection and intraoperative electron irradiation (IOERT) +/- additional EBRT and chemotherapy.

METHODS

From 1981 through 1994, 51 previously irradiated patients with recurrent locally advanced colorectal cancer without evidence of distant metastatic disease were treated at Mayo Clinic Rochester with surgical resection and IOERT +/- additional EBRT. An attempt was made to achieve a gross total resection before IOERT if it could be safely accomplished. The median IOERT dose was 20 Gy (range, 10--30 Gy). Thirty-seven patients received additional EBRT either pre- or postoperatively with doses ranging from 5 to 50.4 Gy (median 25.2 Gy). Twenty patients received 5-fluorouracil +/- leucovorin during EBRT. Three patients received additional cycles of 5-fluorouracil +/- leucovorin as maintenance chemotherapy.

RESULTS

Thirty males and 21 females with a median age of 55 years (range 31--73 years) were treated. Thirty-four patients have died; the median follow-up in surviving patients is 21 months. The median, 2-yr, and 5-yr actuarial overall survivals are 23 months, 48% and 12%, respectively. The 2-yr actuarial central control (within IOERT field) is 72%. Local control at 2 years has been maintained in 60% of patients. There is a trend toward improved local control in patients who received>> or =30 Gy EBRT in addition to IOERT as compared to those who received no EBRT or <30 Gy with 2-yr local control rates of 81% vs. 54%. Distant metastatic disease has developed in 25 patients, and the actuarial rate of distant progression at 2 and 4 years is 56% and 76%, respectively. Peripheral neuropathy was the main IOERT-related toxicity; 16 (32%) patients developed neuropathies (7 mild, 5 moderate, 4 severe). Ureteral narrowing or obstruction occurred in seven patients. All but one patient with neuropathy or ureter fibrosis received IOERT doses>> or =20 Gy.

CONCLUSIONS

Long-term local control can be obtained in a substantial proportion of patients with aggressive combined modality therapy, but long-term survival is poor due to the high rate of distant metastasis. Re-irradiation with EBRT in addition to IOERT appears to improve local control. Strategies to improve survival in these poor-risk patients may include the more routine use of conventional systemic chemotherapy or the addition of novel systemic therapies.