Background Cisplatin-based neoadjuvant chemotherapy (NAC) before cystectomy is the standard of care for muscle-invasive bladder cancer (MIBC), with 25–50% of patients expected to achieve a pathologic response. Validated biomarkers predictive of response are currently lacking. Objective To discover and validate biomarkers predictive of response to NAC for MIBC. Design, setting, and participants Pretreatment MIBC samples prospectively collected from patients treated in two separate clinical trials of cisplatin-based NAC provided the discovery and validation sets. DNA from pretreatment tumor tissue was sequenced for all coding exons of 287 cancer-related genes and was analyzed for base substitutions, indels, copy number alterations, and selected rearrangements in a Clinical Laboratory Improvements Amendments–certified laboratory. Outcome measurements and statistical analysis The mean number of variants and variant status for each gene were correlated with response. Variant data from the discovery cohort were used to create a classification tree to discriminate responders from nonresponders. The resulting decision rule was then tested in the independent validation set. Results and limitations Patients with a pathologic complete response had more alterations than those with residual tumor in both the discovery (p = 0.024) and validation (p = 0.018) sets. In the discovery set, alteration in one or more of the three DNA repair genes ATM, RB1, and FANCC predicted pathologic response (p < 0.001; 87% sensitivity, 100% specificity) and better overall survival (p = 0.007). This test remained predictive for pathologic response in the validation set (p = 0.033), with a trend towards better overall survival (p = 0.055). These results require further validation in additional sample sets. Conclusions: Genomic alterations in the DNA repair-associated genes ATM, RB1, and FANCC predict response and clinical benefit after cisplatin-based chemotherapy for MIBC. The results suggest that defective DNA repair renders tumors sensitive to cisplatin. Patient summary Chemotherapy given before bladder removal (cystectomy) improves the chance of cure for some but not all patients with muscle-invasive bladder cancer. We found a set of genetic mutations that when present in tumor tissue predict benefit from neoadjuvant chemotherapy, suggesting that testing before chemotherapy may help in selecting patients for whom this approach is recommended.

ClinicalTrials.gov identifier: NCT00433511.

IntroductionCirculating tumor cells (CTCs) are tumor cells shed from either primary tumors or its metastases that circulate in the peripheral blood of patients with metastatic cancers. The molecular characterization of the CTCs is critical to identifying the key drivers of cancer metastasis and devising therapeutic approaches. However, the molecular characterization of CTCs is difficult to achieve because their isolation is a major technological challenge.MethodsCTCs from two triple negative breast cancer patients were enriched using CellSearch and single cells selected by DEPArray™. A TP53 R110 fs*13 mutation identified by next generation sequencing in the breast and chest skin biopsies of both patients was studied in single CTCs.ResultsFrom 6 single CTC isolated from one patient, 1 CTC had TP53 R110 delC, 1 CTC showed the TP53 R110 delG mutation, and the remaining 4 single CTCs showed the wild type p53 sequence; a pool of 14 CTCs isolated from the same patient also showed TP53 R110 delC mutation. In the tumor breast tissue of this patient, only the TP53 R110 delG mutation was detected. In the second patient a TP53 R110 delC mutation was detected in the chest wall skin biopsy; from the peripheral blood of this patient, 5 single CTC and 6 clusters of 2 to 6 CTCs were isolated; 3 of the 5 single CTCs showed the TP53 R110 delC mutation and 2 CTCs showed the wild type TP53 allele; from the clusters, 5 showed the TP53 R110 delC mutation, and 1 cluster the wild type TP53 allele. Single white blood cells isolated as controls from both patients only showed the wild type TP53 allele.ConclusionsWe are able to isolate uncontaminated CTCs and achieve single cell molecular analysis. Our studies showed the presence of different CTC sub-clones in patients with metastatic breast cancer. Some CTCs had the same TP53 mutation as their matching tumor samples although others showed either a different TP53 mutation or the wild type allele. Our results indicate that CTCs could represent a non-invasive source of cancer cells from which to determine genetic markers of the disease progression and potential therapeutic targets.Electronic supplementary materialThe online version of this article (doi:10.1186/s13058-014-0445-3) contains supplementary material, which is available to authorized users.

Circulating tumor cells (CTCs) are rare malignant cells found in the peripheral blood that originate from the primary tumor or metastatic sites. New techniques have been developed to isolate and characterize these cells. CTC enumeration has been incorporated into different fields of oncology as a prognostic marker, a tool to monitor therapy response, and a method to understand basic tumor characteristics. This review covers the different techniques available for isolation of CTCs, the clinical utility of CTCs in breast, prostate, and colon cancer, and future directions in this field.

A B S T R A C T PurposeTwo phase I studies were conducted of ABR-217620 alone or in combination with docetaxel. This is a recombinant fusion protein consisting of a mutated variant of the superantigen staphylococcal enterotoxin E (SEA/E-120) linked to fragment antigen binding moiety of a monoclonal antibody recognizing the tumor-associated antigen 5T4. Patients and MethodsPatients with non-small-cell lung cancer (NSCLC), pancreatic cancer (PC), and renal cell cancer (RCC) received 5 daily boluses of ABR-217620 (3-month cycles) in escalating doses to determine the maximum-tolerated dose (MTD; ABR-217620 dose escalation monotherapy [MONO] study). Doses were selected based on individual patient anti-SEA/E-120 titers pretreatment. Patients with NSCLC received 4 daily, escalating doses of ABR-217620 followed by docetaxel in 21-day cycles (ABR-217620 dose escalation combination with docetaxel [COMBO] study). ResultsThirty-nine patients were enrolled in the MONO study and 13 were enrolled in the COMBO study. The monotherapy MTD was 26 g/kg (NSCLC and PC) and 15 g/kg (RCC). Dose-limiting toxicities (DLTs) in the MONO study were fever, hypotension, acute liver toxicity, and vascular leak syndrome. In the COMBO study, the MTD was 22 g/kg (neutropenic sepsis). Adverse events included grade 1 to 2 fever, hypotension, nausea, and chills. Treatment caused a systemic increase of inflammatory cytokines and selective expansion of SEA/E-120 reactive T-cells. Tumor biopsies demonstrated T-cell infiltration after therapy. Fourteen patients (36%) had stable disease (SD) on day 56 of the MONO study. Two patients (15%) in the COMBO study had partial responses, one in a patient with progressive disease on prior docetaxel, and five patients (38%) had SD on day 56. ConclusionABR-217620 was well tolerated with evidence of immunological activity and antitumor activity.