This week in NEJM, an international team of researchers presents findings from a study of the androgen inhibitor abiraterone in metastatic prostate cancer. Biosynthesis of extragonadal androgen may contribute to the progression of castration-resistant prostate cancer, the authors write. To evaluate the effects of abiraterone acetate, which inhibits androgen biosynthesis, on the survival rate of patient with metastatic castration-resistant prostate cancer, the researchers randomly assigned 797 patients who had previously received chemotherapy to receive abiraterone with prednisone, and assigned 398 previous chemotherapy recipients to a placebo group. After a median follow-up of 12.8 months, the team found that overall survival was 14.8 months in the abiraterone group versus 10.9 months in the placebo group. "All secondary end points, including time to PSA progression (10.2 vs. 6.6 months), progression-free survival (5.6 months vs. 3.6 months), and PSA response rate (29% vs. 6%), favored the treatment group," the authors add.
In an editorial on treatment options for metastatic prostate cancer, Johns Hopkins oncologists Emmanuel Antonarakis and Mario Eisenberger say the abiraterone study presents proof of principle that metastatic castration-resistant prostate cancer remains androgen-driven, and that the findings provide "sufficient evidence" that abiraterone should be used in all patients with metastatic castration-resistant prostate cancer, even those with no previous chemotherapy treatment. Although treatment choices for men with metastatic castration-resistant prostate cancer have increased and outcomes have improved, the duration of progression-free and overall survival still remains relatively short," Antonarakis and Eisenberg write. "It is clear, however, that our knowledge of the biologic mechanisms involved in the progression of metastatic castration-resistant prostate cancer has reached a level at which the discovery of more effective targeted approaches will probably further improve outcomes."
Also in NEJM this week, the Massey Cancer Center's Thomas Smith and Bruce Hillner say the trend in rising prices for cancer treatments is "not sustainable," and that oncologists must find ways to reduce the costs of everyday care for patients. "Medical oncologists directly or indirectly control or influence the majority of cancer care costs, including the use and choice of drugs, the types of supportive care, the frequency of imaging, and the number and extent of hospitalizations," they write. There are changes that could be made to clinical practice, such as targeting surveillance testing or imaging, trying sequential monotherapy instead of combination therapies, limiting chemotherapy based on a patient's performance status, and reducing the chemotherapy dose in metastatic solid cancers, Smith and Hillner say. It is also important for patients and clinicians to engage in end-of-life discussions, and for clinicians to help patients keep their expectations realistic, they add.