Genetic Factors Associated with Prostate Cancer Conversion from Active Surveillance to Treatment.

Men diagnosed with low-risk prostate cancer (PC) are increasingly electing active surveillance (AS) as their initial management strategy. While this may reduce the side effects of treatment for prostate cancer, many men on AS eventually convert to active treatment. PC is one of the most heritable cancers, and genetic factors that predispose to aggressive tumors may help distinguish men who are more likely to discontinue AS. To investigate this, we undertook a multi-institutional genome-wide association study (GWAS) of 5,222 PC patients and 1,139 other patients from replication cohorts, all of whom initially elected AS and were followed over time for the potential outcome of conversion from AS to active treatment. In the GWAS we detected 18 variants associated with conversion, 15 of which were not previously associated with PC risk. With a transcriptome-wide association study (TWAS), we found two genes associated with conversion (MAST3, p = 6.9×10-7 and GAB2, p = 2.0×10-6). Moreover, increasing values of a previously validated 269-variant genetic risk score (GRS) for PC was positively associated with conversion (e.g., comparing the highest to the two middle deciles gave a hazard ratio [HR] = 1.13; 95% Confidence Interval [CI]= 0.94-1.36); whereas, decreasing values of a 36-variant GRS for prostate-specific antigen (PSA) levels were positively associated with conversion (e.g., comparing the lowest to the two middle deciles gave a HR = 1.25; 95% CI, 1.04-1.50). These results suggest that germline genetics may help inform and individualize the decision of AS-or the intensity of monitoring on AS-versus treatment for the initial management of patients with low-risk PC.

Employing the treatment-free interval of intermittent androgen ablation to screen candidate prostate cancer therapies.

BACKGROUND: Because neither continuous nor intermittent hormonal therapy is curative, we designed a clinical model to screen new drugs for additive or synergistic effects with hormonal therapy and used IM862, a naturally occurring dipeptide with antiangiogenic and immunomodulatory properties, to test it. METHODS: Patients with prostate cancer who had rising PSA levels after radical prostatectomy and/or radiation therapy were given combined androgen ablation for 3 months. After 2 months' treatment, patients were randomly assigned in a double-blind fashion to receive intranasal IM862 or placebo daily. Treatment continued for 6 months or until disease progression, which was defined by a rising serum PSA level, the appearance of new skeletal or extraskeletal metastatic disease, or new symptoms requiring intervention. RESULTS: Seventy-one patients were evaluable for response. Median time to PSA progression was not reached in either group. At 6 months, disease had progressed in 14 (41%) of the 34 patients receiving treatment and 18 (49%) of the 37 receiving placebo (P = 0.39). No significant toxicities emerged. CONCLUSIONS: The model was demonstrated to be an efficient platform for new drug screening; however, IM862, though well tolerated, failed to demonstrate superiority over placebo in prolonging time to PSA progression.

Phase II study of capecitabine single-agent therapy in patients with metastatic renal cell carcinoma.

Fluoropyrimidines are known to have modest activity in the treatment of metastatic renal cell carcinoma (RCC). Capecitabine is an orally administered prodrug that is converted to fluorouracil and is of potential use in the treatment of this disease. We conducted a Phase II clinical trial of capecitabine administered as a single agent to patients with metastatic RCC. The treatment consisted of 1250 mg/m(2) capecitabine orally, twice daily (2500 mg/m(2) per day) days 1-14, repeated every 21 days. There were 15 patients, including 13 men and 2 women, who underwent a total of 67 cycles (median 3.5; range 1-15). Nine patients had undergone prior systemic therapy consisting of interferon-alpha in 3, interleukin-2 in 1, interferon-alpha plus interleukin-2 in 4, and investigational therapy with bryostatin-1 in 1. There were 14 patients assessable for response (one withdrew), and no responses were seen. Median time to progression was 9 weeks (range 1-45). There were 3 patients (21%) who had stable disease for 18, 39, and 45 weeks. Hematologic toxicity was mild. Three patients had grade 3 or 4 gastrointestinal toxicity, and 3 required dose reductions. There were 2 early deaths, including 1 patient with pulmonary edema and 1 with hypotension. The study was terminated because there were no responses in the first 14 assessable patients, indicating that the response rate was likely to be less than 20%. We conclude that single-agent capecitabine has minimal activity for the treatment of metastatic RCC.