Multiparametric magnetic resonance imaging (mpMRI) and MRI fusion targeted biopsy (FTB) detect significant prostate cancer (sPCa) more accurately than conventional biopsies alone.

To evaluate the detection accuracy of mpMRI and FTB on radical prostatectomy (RP) specimen.

From a cohort of 755 men who underwent transperineal MRI and transrectal ultrasound fusion biopsy under general anesthesia between 2012 and 2014, we retrospectively analyzed 120 consecutive patients who had subsequent RP. All received saturation biopsy (SB) in addition to FTB of lesions with Prostate Imaging Reporting and Data System (PI-RADS) score ≥2.

The index lesion was defined as the lesion with extraprostatic extension, the highest Gleason score (GS), or the largest tumor volume (TV) if GS were the same, in order of priority. GS 3+3 and TV ≥1.3ml or GS ≥3+4 and TV ≥0.55ml were considered sPCa. We assessed the detection accuracy by mpMRI and different biopsy approaches and analyzed lesion agreement between mpMRI and RP specimen.

Overall, 120 index and 71 nonindex lesions were detected. Overall, 107 (89%) index and 51 (72%) nonindex lesions harbored sPCa. MpMRI detected 110 of 120 (92%) index lesions, FTB (two cores per lesion) alone diagnosed 96 of 120 (80%) index lesions, and SB alone diagnosed 110 of 120 (92%) index lesions. Combined SB and FTB detected 115 of 120 (96%) index foci. FTB performed significantly less accurately compared with mpMRI (p=0.02) and the combination for index lesion detection (p=0.002). Combined FTB and SB detected 97% of all sPCa lesions and was superior to mpMRI (85%), FTB (79%), and SB (88%) alone (p<0.001 each). Spearman's rank correlation coefficient for index lesion agreement between mpMRI and RP was 0.87 (p<0.001). Limitations included the retrospective design, multiple operators, and nonblinding of radiologists.

MpMRI identified 92% of index lesions compared with RP histopathology. The combination of FTB and SB was superior to both approaches alone, reliably detecting 97% of sPCa lesions.

Multiparametric magnetic resonance imaging detects the index lesion accurately in 9 of 10 patients; however, the combined biopsy approach, while missing less significant cancer, comes at the cost of detecting more insignificant cancer.

Despite decades of research, ovarian cancer is still associated with unacceptably high mortality rates, which must be addressed by novel therapeutic approaches. One avenue through which this may be achieved is targeting of tumor-initiating 'Cancer Stem Cells' (CSCs). CSCs are sufficient to generate primary and recurrent disease through extensive rounds of asymmetric division, which maintain the CSC pool while producing the tissues that form the bulk of the tumor. CSCs thrive in the harsh tumor niche, are generally refractory to therapeutic intervention and closely-linked to the Epithelial-Mesenchymal Transition process, which facilitates invasion and metastasis. While it is well-accepted that CSC-targeting must be assessed as a novel therapeutic avenue, few ovarian CSC models have been developed due to perceived and actual difficulties associated with the process of 'CSC Discovery'. In this article we review contemporary approaches to CSC Discovery and argue that this process should start with an understanding of the specific challenges associated with clinical intervention, laying the pipeline backwards towards CSC Discovery. Such an approach would expedite the bridging of the gap between laboratory isolation and clinical targeting of ovarian CSCs.

It is widely believed that targeting the tumour-initiating cancer stem cell (CSC) component of malignancy has great therapeutic potential, particularly in therapy-resistant disease. However, despite concerted efforts, CSC-targeting strategies have not been efficiently translated to the clinic. This is partly due to our incomplete understanding of the mechanisms underlying CSC therapy-resistance. In particular, the relationship between therapy-resistance and the organisation of CSCs as Stem-Progenitor-Differentiated cell hierarchies has not been widely studied. In this review we argue that modern clinical strategies should appreciate that the CSC hierarchy is a dynamic target that contains sensitive and resistant components and expresses a collection of therapy-resisting mechanisms. We propose that the CSC hierarchy at primary presentation changes in response to clinical intervention, resulting in a recurrent malignancy that should be targeted differently. As such, addressing the hierarchical organisation of CSCs into our bench-side theory should expedite translation of CSC-targeting to bed-side practice. In conclusion, we discuss strategies through which we can catch these moving clinical targets to specifically compromise therapy-resistant disease.

Non-small cell lung cancer (NSCLC) accounts for a large proportion of cancer deaths and is characterized by low treatment response rates and poor overall prognosis. In the absence of specific treatable mutations, cisplatin-based chemotherapy plays an important role in the treatment of this disease. Unfortunately, the development of resistance has become a major therapeutic challenge in the use of this cytotoxic drug. Elucidating the mechanisms underlying this resistance phenotype, may result in the development of novel agents that enhance sensitivity to cisplatin in lung cancer patients. In this study, targeting the cancer stem cell activity of aldehyde dehydrogenase 1 (ALDH1) was investigated as a strategy to overcome chemoresistance in NSCLC. Tumors from NSCLC patients showed an increase in their profile of pluripotent stemness genes. Cisplatin exposure induced the emergence or expansion of an ALDH1-positive subpopulation in cisplatin sensitive and resistant NSCLC cell lines, respectively, further enhancing cisplatin resistance. Using the Aldefluor assay and FACS analysis, ALDH1 subpopulations were isolated and evaluated in terms of stem cell characteristics. Only ALDH1-positive cells exhibited asymmetric division, cisplatin resistance and increased expression of stem cell factors in vitro. Xenograft studies in NOD/SCID mice demonstrated efficient tumorigenesis from low cell numbers of ALDH1-positive and ALDH1-negative subpopulations. Targeting ALDH1 with Diethylaminobenzaldehyde (DEAB) and Disulfiram, significantly re-sensitized resistant lung cancer cells to the cytotoxic effects of cisplatin. Our data demonstrate the existence of a lung CSC population and suggest a role for targeting ALDH1 as a potential therapeutic strategy in re-sensitizing NSCLC cells to the cytotoxic effects of cisplatin.

Resistance to neoadjuvant chemoradiation therapy (CRT) remains a critical barrier to the effective treatment of esophageal adenocarcinoma (EAC). Cancer stem-like cells (CSCs) are a distinct subpopulation of cells implicated in the resistance of tumors to anti-cancer therapy. However, their role in the resistance of EAC to CRT is largely unknown. In this study, using a novel in vitro isogenic model of radioresistant EAC, we demonstrate that radioresistant EAC cells have enhanced tumorigenicity in vivo, increased expression of CSC-associated markers and enhanced holoclone forming ability. Further investigation identified a subpopulation of cells that are characterised by high aldehyde dehydrogenase (ALDH) activity, enhanced radioresistance and decreased expression of miR-17-5p. In vitro, miR-17-5p was demonstrated to significantly sensitise radioresistant cells to X-ray radiation and promoted the repression of genes with miR-17-5p binding sites, such as C6orf120. In vivo, miR-17-5p was significantly decreased, whilst C6orf120 was significantly increased, in pre-treatment EAC tumour samples from patients who demonstrated a poor response to neoadjuvant CRT. This study sheds novel insights into the role of CSCs in the resistance of EAC to CRT and highlights miR-17-5p as a potential biomarker of CRT sensitivity and novel therapeutic target in treatment resistant EAC.

Magnetic resonance imaging (MRI) and prostate specific membrane antigen (PSMA)- positron emission tomography (PET)/computed tomography (CT)-imaging of prostate cancer (PCa) are emerging techniques to assess the presence of significant disease and tumor progression. It is not known, however, whether and to what extent lesions detected by these imaging techniques correlate with genomic features of PCa. The aim of this study was therefore to define a genomic index lesion based on chromosomal copy number alterations (CNAs) as marker for tumor aggressiveness in prostate biopsies in direct correlation to multiparametric (mp) MRI and 68Ga-PSMA-PET/CT imaging features. CNA profiles of 46 biopsies from five consecutive patients with clinically high-risk PCa were obtained from radiologically suspicious and unsuspicious areas. All patients underwent mpMRI, MRI/TRUS-fusion biopsy, 68Ga-PSMA-PET/CT and a radical prostatectomy. CNAs were directly correlated to imaging features and radiogenomic analyses were performed. Highly significant CNAs (≥10 Mbp) were found in 22 of 46 biopsies. Chromosome 8p, 13q and 5q losses were the most common findings. There was an strong correspondence between the radiologic and the genomic index lesions. The radiogenomic analyses suggest the feasibility of developing radiologic signatures that can distinguish between genomically more or less aggressive lesions. In conclusion, imaging features of mpMRI and 68Ga-PSMA-PET/CT can guide to the genomically most aggressive lesion of a PCa. Radiogenomics may help to better differentiate between indolent and aggressive PCa in the future.

A venous tumor thrombus (VTT) is a potentially lethal complication of renal cell carcinoma (RCC) but virtually nothing is known about the underlying natural history. Based on our observation that venous thrombi contain significant numbers of viable tumor cells, we applied multiregion whole exome sequencing to a total of 37 primary tumor and VTT samples including normal tissue specimens from five consecutive patients. Our findings demonstrate mutational heterogeneity between primary tumor and VTT with 106 of 483 genes (22%) harboring functional SNVs and/or indels altered in either primary tumor or thrombus. Reconstruction of the clonal phylogeny showed clustering of tumor samples and VTT samples, respectively, in the majority of tumors. However, no new subclones were detected suggesting that pre-existing subclones of the primary tumor drive VTT formation. Importantly, we found several lines of evidence for "BRCAness" in a subset of tumors. These included mutations in genes that confer "BRCAness", a mutational signature and an increase of small indels. Re-analysis of SNV calls from the TCGA KIRC-US cohort confirmed a high frequency of the "BRCAness" mutational signature AC3 in clear cell RCC. Our findings warrant further pre-clinical experiments and may lead to novel personalized therapies for RCC patients.

Laparoscopic partial nephrectomy (LPN) remains challenging in endophytic and complex kidney tumors as the clear understanding of tumor location and spreading depends on a precise analysis of available imaging. The purpose of this study was to investigate navigated kidney surgery using intraoperative cone-beam computed tomography (CBCT) images in conjunction with a previously proposed method for augmented reality (AR) guidance for safe LPN.

The concept proposed is based on using an intraoperative CBCT scan for (1) marker-based AR guidance for fast and reliable tumor access and (2) enhancement of real-time fluoroscopy images for accurate tumor resection. Workflow and accuracy of the system were assessed using a porcine kidney model. Ten patients with complex or endophytic tumor localization and R.E.N.A.L. Nephrometry Score of at least nine scheduled for LPN were included in this study. Patients received an intraoperative CBCT after marker placement. Defining the resection line was assisted by AR. In addition, fluoroscopy imaging for depth perception was used for assistance during dissection. Feasibility and performance were assessed by histopathological results, peri- and postoperative data.

Surgery was performed successfully and negative margins were found in all cases. Segmental branches of the renal artery shifted as much as 10 mm in the vertical and 11 mm in the sagittal axis intraoperatively compared to preoperative imaging. Fluoroscopy to intraoperative computed tomography image fusion enabled enhanced depth perception during dissection in all cases. Radiation dose area product was 4.8 mGym2.

The application of the navigation system is feasible and allows for safe and direct access to complex or endophytic renal masses. Radiation limits the application to selected indications.

<AbstractText>Retzius-sparing robot-assisted laparoscopic radical prostatectomy (rsRARP) allows entire prostatectomy procedure via the pouch of Douglas. In low- and intermediate-risk prostate cancer (PCa) there is level 1 evidence that the Retzius-sparing approach impacts early continence recovery. Since specific data on aggressive and locally advanced cancer is lacking and avoiding rsRARP is presently suggested, we investigated urinary and sexual recovery, perioperative complications and early oncologic outcomes after rsRARP in this particular cohort.</AbstractText><AbstractText>Prospectively collected data of 50 consecutive men (median age 66 years) with high-risk PCa who underwent rsRARP in a single institution was analysed retrospectively. The follow-up for all patients was 12 months after surgery.</AbstractText><AbstractText>3 vs. 12 months after surgery, 82% vs. 98% of men used no pad or one safety pad and 50% vs. 72% used no pad. 89% of patients did not observe a decline of continence if postoperative radiotherapy was carried out. Considering the 17 preoperatively potent patients who underwent bi- or unilateral nerve-sparing surgery, 41% reported their first sexual intercourse within 1 year after rsRARP. 84% of patients had ≥pT3a disease and 42% positive surgical margins. A lymphadenectomy was done in 94% of patients with a median lymph node removal of 15 and lymph node metastasis in 13%. 34% underwent adjuvant radiotherapy and 22% adjuvant androgen deprivation therapy (ADT). 1-year recurrence-free survival was 96%, including 25% of patients on adjuvant or salvage ADT.</AbstractText><AbstractText>RsRARP in high-risk PCa is feasible and results in excellent continence rates, even after postoperative radiotherapy. The potency rates are promising but need further clarification in larger cohorts. Reliable oncologic outcomes require longterm follow-up and are awaited.</AbstractText>

OBJECTIVE

To show the benefit of three-dimensional (3D) reconstructions of preoperative imaging for surgical performance.

METHODS

A laparoscopic training environment with 15 hidden lymph nodes was designed. Three of them were marked with radiographic contrast agent and were only distinguishable from unmarked nodes via CT imaging. Thirty-six surgeons were divided into two groups. To group 1 the unprocessed CT data were shown. Group 2 was additionally shown a 3D reconstruction of the anatomy. Time of studying the imaging was recorded. All surgeons had to find the three target lymph nodes laparoscopically. Time to fulfill this task and errors was measured. Afterward, the 3D reconstruction was also shown to group 1. Then, all participants completed a questionnaire. Furthermore, 3D reconstructions were used in 15 clinical cases of partial nephrectomy or lymphadenectomy, and surgeons' opinion was evaluated with an additional questionnaire. The imaging and 3D reconstructions were available on a mobile device.

RESULTS

The time of studying the imaging to gain confidence was significantly shorter with the 3D reconstruction. Laparoscopic intervention time was shortened and errors were reduced significantly within group 2. The clinical application of 3D reconstructions in difficult cases was believed to be helpful.

CONCLUSIONS

3D reconstructions of preoperative imaging lead to better surgical performance in a difficult laparoscopic training environment. Surgeons gain a 3D impression of patients' individual anatomy easier, faster, and more reliable. Providing 3D reconstructions previous to surgery should be routinely implemented for patients with complex anatomical situations.

We have previously reported that myeloid differentiation primary response gene 88 (MyD88) is downregulated during all-trans retinoic acid (RA)-induced differentiation of pluripotent NTera2 human embryonal carcinoma cells (hECCs), whereas its maintained expression is associated with RA differentiation resistance in nullipotent 2102Ep hECCs. MyD88 is the main adapter for toll-like receptor (TLR) signalling, where it determines the secretion of chemokines and cytokines in response to pathogens. In this study, we report that loss of MyD88 is essential for RA-facilitated differentiation of hECCs. Functional analysis using a specific MyD88 peptide inhibitor (PepInh) demonstrated that high MyD88 expression in the self-renewal state inhibits the expression of a specific set of HOX genes. In NTera2 cells, MyD88 is downregulated during RA-induced differentiation, a mechanism that could be broadly replicated by MyD88 PepInh treatment of 2102Ep cells. Notably, MyD88 inhibition transitioned 2102Ep cells into a stable, self-renewing state that appears to be primed for differentiation upon addition of RA. At a molecular level, MyD88 inhibition combined with RA treatment upregulated HOX, RA signalling and TLR signalling genes. These events permit differentiation through a standard downregulation of Oct4-Sox2-Nanog mechanism. In line with its role in regulating secretion of specific proteins, conditioned media experiments demonstrated that differentiated (MyD88 low) NTera2 cell media was sufficient to differentiate NTera2 cells. Protein array analysis indicated that this was owing to secretion of factors known to regulate angiogenesis, neurogenesis and all three branches of TGF-β Superfamily signalling. Collectively, these data offer new insights into RA controlled differentiation of pluripotent cells, with notable parallels to the ground state model of embryonic stem cell self-renewal. These data may provide insights to facilitate improved differentiation protocols for regenerative medicine and differentiation-therapies in cancer treatment.

In recent years, PSMA-targeting PET tracers such as 68Ga-PSMA-11 have shown promising results, thus contributing to a better management of prostate cancer patients. At the present time, 68Ga-PSMA-11 is most frequently used for diagnostic evaluation in the setting of biochemical recurrence of prostate cancer. In this context, the 68Ga-PSMA-11 PET/CT delivers superior detection rates compared to conventional imaging, especially for the detection of small, unsuspicious lesions or lesions in the presence of low PSA values. Furthermore, 68Ga-PSMA PET imaging seems to be an encouraging alternative for the staging of high-risk patients, particularly in combination with multiparametric MRI. In addition to the increasing use of PSMA ligands in clinical diagnostics, some variants have also been successfully applied in therapy. Advanced metastasized prostate cancer patients showed a good response to PSMA radioligand therapy with tolerable side-effects after failure of guideline-compliant treatment.Due to recent developments, PSMA ligands will continue to play an important role in the management of prostate cancer patients and will be more widely used in the future.

OBJECTIVE

This study is a prospective evaluation of a volume-based, computer-assisted method for transperineal optimized prostate (TOP) biopsy. The TOP algorithm automates core planning for systematic prostate biopsies using the 3-dimensional organ contour and an alterable volume for tumors to be excluded.

METHODS

MRI-transrectal ultrasound fusion biopsy with MRI-targeted biopsies (TBs) and systematic-TOP biopsies were performed on 172 men between October 2013 and March 2014. Systematic biopsies were placed according to TOP for detection of tumor volumes >0.5 mL with a minimum of 80% organ coverage in prostates up to 50 mL (70% in larger organs).

RESULTS

Median 24 TOP cores and 3 MRI-TBs have been placed. Prostate cancer (PCa) was detected in 112 of 172 (65%) of men; TOP detected 109 (97%) and TB 62 (55%). Significant cancer (Gleason score ≥7) was detected in 75 (44%) of men and of these TOP detected 73 of 75 (97%) and TB 51 of 75 (68%). Overall, systematic-TOP sampling significantly outperformed TB for the detection of both, all PCa as well as significant PCa (p < 0.0001, p = 0.0005).

CONCLUSIONS

The TOP method is innovative by integrating the individual prostate volume and PCa volume detection thresholds. In the present cohort, it diagnosed more significant tumors than TB alone. However, at the same time, more low-risk tumors are detected.

It is long established that tumour-initiating cancer stem cells (CSCs) possess chemoresistant properties. However, little is known of the mechanisms involved, particularly with respect to the organisation of CSCs as stem-progenitor-differentiated cell hierarchies. Here we aimed to elucidate the relationship between CSC hierarchies and chemoresistance in an ovarian cancer model. Using a single cell-based approach to CSC discovery and validation, we report a novel, four-component CSC hierarchy based around the markers cluster of differentiation 10 (CD10) and aldehyde dehydrogenase (ALDH). In a change to our understanding of CSC biology, resistance to chemotherapy drug cisplatin was found to be the sole property of CD10-/ALDH- CSCs, while all four CSC types were sensitive to chemotherapy drug paclitaxel. Cisplatin treatment quickly altered the hierarchy, resulting in a three-component hierarchy dominated by the cisplatin-resistant CD10-/ALDH- CSC. This organisation was found to be hard-wired in a long-term cisplatin-adapted model, where again CD10-/ALDH- CSCs were the sole cisplatin-resistant component, and all CSC types remained paclitaxel-sensitive. Molecular analysis indicated that cisplatin resistance is associated with inherent- and adaptive-specific drug efflux and DNA-damage repair mechanisms. Clinically, low CD10 expression was consistent with a specific set of ovarian cancer patient samples. Collectively, these data advance our understanding of the relationship between CSC hierarchies and chemoresistance, which was shown to be CSC- and drug-type specific, and facilitated by specific and synergistic inherent and adaptive mechanisms. Furthermore, our data indicate that primary stage targeting of CD10-/ALDH- CSCs in specific ovarian cancer patients in future may facilitate targeting of recurrent disease, before it ever develops.