Single-nucleotide polymorphism associations with efficacy and toxicity in metastatic castration-resistant prostate cancer treated with cabazitaxel.

Background: The aim of this study was to evaluate the impact of certain single-nucleotide polymorphisms (SNPs) in cabazitaxel activity and toxicity in patients with metastatic castration-resistant prostate cancer (mCRPC). Patients & methods: 56 SNPs in five genes (CYP3A4, CYP3A5, ABCB1, TUBB1 and CYP2C8) were genotyped in 67 mCRPC patients and their correlation with outcomes analyzed. Results:TUBB1-rs151352 (hazard ratio: 0.52) and CYP2C8-rs1341164 (hazard ratio: 0.53) were associated with better overall survival, and CYP2C8-rs1058932 with biochemical progression (odds ratio: 6.60) in multivariate analysis. ABCB1-rs17327624 correlated with severe toxicity ≥grade 3 (odds ratio: 8.56) and CYP2C8-rs11572093 with asthenia (odds ratio: 8.12). Conclusion: Genetic variants in mCRPC patients could explain different outcomes with cabazitaxel. Nonetheless, the small sample size and the high number of SNPs analyzed mean that the results are only hypothesis-generating and require further validation.

Final Overall Survival Analysis of the SOGUG Phase 2 MAJA Study: Maintenance Vinflunine Versus Best Supportive Care After First-Line Chemotherapy in Advanced Urothelial Carcinoma.

INTRODUCTION: The MAJA study compared vinflunine (VFL) plus best supportive care (BSC) maintenance therapy versus BSC alone in advanced urothelial carcinoma responsive to first-line chemotherapy. The primary end point of progression-free survival was achieved. We present the final overall survival (OS) and long-term follow-up safety analyses. PATIENTS AND METHODS: Patients were enrolled, and a subsequent post hoc analysis was performed on the basis of radiologic response or stabilization to first-line cisplatin/gemcitabine (CG) chemotherapy (4-6 cycles), according to Response Evaluation Criteria in Solid Tumors (RECIST). VFL + BSC versus BSC alone were randomly assigned until disease progression. RESULTS: At final analysis, 58 patients (66.7%) had died while 29 (33.3%) had survived; the BSC arm had higher mortality (VFL + BSC, n = 26, 59.1% vs. BSC, n = 32, 74.4%). Median follow-up of surviving patients was 38.8 months (interquartile range, 23.8-61.6). Median OS was 16.7 months (95% confidence interval, 0-34.5) in VFL and 13.2 months (95% confidence interval, 6-20.4) in the BSC groups (hazard ratio, 0.736; 95% confidence interval, 0.44-1.24, P = .182). Post hoc group division did not affect median OS in either study arm. CONCLUSION: Final analysis supported a benefit of VFL in maintenance therapy in patients with disease control after first-line treatment with CG, with no unexpected long-term adverse effects. The study was insufficiently powered to show a significant OS advantage.

Metastatic renal cell carcinoma: radiologic findings and assessment of response to targeted antiangiogenic therapy by using multidetector CT.

Recent advances in treatment of metastatic renal cell carcinoma (RCC), such as new molecular therapies that use novel antiangiogenic agents, have led to revision of the most frequently used guideline to evaluate tumor response to therapy: Response Evaluation Criteria in Solid Tumors (RECIST 1.1). Assessment of the response of metastatic RCC to therapy has traditionally been based on changes in target lesion size. However, the mechanism of action of newer antiangiogenic therapies is more cytostatic than cytotoxic, which leads to disease stabilization rather than to tumor regression. This change in tumor response makes RECIST 1.1--a system whose criteria are based exclusively on tumor size--inadequate to discriminate patients with early tumor progression from those with more progression-free disease and prolonged survival. New criteria such as changes in attenuation, morphology, and structure, as seen at contrast-enhanced multidetector computed tomography (CT), are being incorporated into new classifications used to assess response of metastatic RCC to antiangiogenic therapies. The new classifications provide better assessments of tumor response to the new therapies, but they have some limitations. The authors provide a practical review of these systems--the Choi, modified Choi, and Morphology, Attenuation, Size, and Structure (MASS) criteria--by explaining their differences and limitations that may influence the feasibility and reproducibility of these classifications. The authors review the use of multidetector CT in the detection of metastatic RCC and the different appearances and locations of these lesions. They also provide an overview of the new antiangiogenic therapies and their mechanisms of action and a brief introduction to functional imaging techniques. Functional imaging techniques, especially dynamic contrast-enhanced CT, seem promising for assessing response of metastatic RCC to treatment. Nonetheless, further studies are needed before functional imaging can be used in routine clinical practice.