THE "NEW" PROSTATE CANCER INFOLINK

In today’s news reports there are items on:

• Genetic modifications and prostate cancer risk and development
• Situation-specific prostate biopsy strategies
• A viral vector-prodrug combination in treatment of local and locally advanced disease
• Docetaxel + ¹⁵³Sm lexidronam in metastatic CRPC

Fitzgerald et al. have confirmed that several recently identified SNPs of DNA are associated with prostate cancer risk; however, they note that these genetic variations only confer a low to moderate relative risk of prostate cancer and are generally not associated with more aggressive disease features. (We have a way to go before genetic testing is going to help us diagnose clincially significant prostate cancer with high accuracy.)

King et al. have offered additional information suggesting that there is an association between the TMPRSS2-ERG fusion gene and loss of the PTEN gene in the development of prostate cancer tumors.

Patel and Jones have provided insights on optimal strategies for prostate biopsy given various clinical situations: first-time biopsy (the 10-14 core extended biopsy scheme);  clinical suspicion of prostate cancer but prior negative biopsy (saturation biopsy with a focus on lateral and apical cores);  staging patients undergoing active surveillance protocols (saturation biopsy due to the risk of pathological upgrading and clinical upstaging).

Patel et al. have reported data from a  Phase I/II clinical trial of a virus vector combined with a systemic prodrug called CB1954. One group of patients with localized prostate cancer who were scheduled for radical prostatectomy received virus alone, prior to surgery. A second group with local failure following primary treatment received virus plus prodrug to establish safety and tolerability. Then, based on acceptable safety data and indications of PSA responses, some of the patients received virus at a single dose level plus prodrug. A total of 19 patients received virus plus prodrug and 14 of these had a repeat treatment. There appeared to be minimal adverse reactions to this treatment, and there was  an increase in the time to 10 percent PSA progression in 6/18 patients at 6 months.

Morris et al. have published Phase I data on the combination of docetaxel chemotherapy with the injectable radiotherapeutic agent samarium-153 lexidronam in treatment of men with metastatic castration-resistant prostate cancer. They report that docetaxel and ¹⁵³Sm lexidronam can be combined safely at full doses over repeated cycles. Responses (> 50 percent reduction in PSA level) were noted in 15/28 patients with taxane-resistant disease tested.