Friday’s news and reports: December 26, 2008

With at least a dozen new reports available today, we have chosen to focus only on the most significant, several of which may be of clinical importance now or in the near future. Most of the other items provide minimal new information and can be accessed through the UroToday web site by those who are interested.

Guy et al. have reviewed current understanding of the potential for genetic testing for prostate cancer. They confirm current awareness of 23 genetic variants that appear to have some impact on prostate cancer risk. They acknowledge that there is already the potential to develop a genetic test based on these data. They state, however, that such an action is premature (in their opinions), because prostate cancer risk “can not be evaluated fully at this stage and the appropriate screening protocols need to be developed.” They believe that further validation studies, as well as studies to explore the psychological implications of genetic profile testing, are still vital prior to making such a test available to the public. The “New” Prostate Cancer InfoLink is in complete agreement with this general opinion.

Kawakami et al. have demonstrated that a patient’s prior history of (non-prostatic) malignancy is an independent predictor for a positive prostate biopsy in Japanese patients believed to be at possible risk for prostate cancer. While this demonstration is only currently applicable to Japanese patients, it is believed to be the first time it has been shown in any patient population. A total of 1,767 consecutive Japanese men with PSA values <10 ng/ml who underwent prostate biopsy were included in the study cohort. A history of malignancy was reported in 269/1,767 patients, with a total of 312 primary sites. Univariate and multivariate analyses revealed that DRE, PSA, age, family history, and number of previous malignancies are all independent and significant predictors of a positive biopsy result. The authors developed a predictive nomogram that included all five of the above-mentioned variables. External validation of the nomogram showed that it was more accurate than a nomogram based on PSA data only or on PSA and DRE data.

Several studies have suggested that there is or at least may be a relationship between body mass index and prostate cancer risk/biology. Capitanio et al., in a study of 1,490 consecutively screened Canadian men with no known prior history of prostate cancer risk, were unable to find such an association. They conclude that body mass index has no significant impact on either total PSA or free/total PSA ratio in Canadian males with no history of prostate cancer.

Dasgupta and Kirby have reviewed the currently available literature on the effectiveness and safety of robot-assisted lapaoroscopic radical prostatatectomy (RALP). According to this review, 65 percent of all radical prostatectomies in the USA are now being conducted using this technique. In other parts of the world, acceptance has been slower (which is likely to have something to do with the cost of the equipment). They note the known benefits of RALP compared to open radical prostatectomy (reduced blood loss, decreased pain, early mobilization, shorter hospital stay, and lower margin rates). As they are careful to point out, however, “There is no definitive evidence to show an advantage over standard laparoscopy” (i.e., non-robot-assisted LRP).

Wilson et al. have reported that the combination of docetaxel with dexamethasone (as opposed to the commonly used prednisone) may be highly effective in the treatment of castration-resistant, metastatic prostate cancer because dexamethasone “potentiates the antiangiogenic activity of docetaxel, suggesting a putative mechanism for the palliative and survival benefits of these agents.” This comes as no great surprise to The “New” Prostate Cancer InfoLink. Combination of dexamethasone with selected chemotherapeutic agents has been shown to be highly effective in the treatment of some other cancers (e.g., lenalidomide + low-dose dexamethasone in treatment of multiple myeloma). Furthermore, we have noted that one of the most successful phase II trials of abiraterone acetate was in combination with dexamethasone. When we asked Dr. DeBono at the annual meeting of ASCO this year why the Phase III trial of abiraterone was going to compare abiraterone acetate + prednisone to a placebo + prednisone instead of replacing the ptrednisone with dexamethasone, he told us that prednisone was the customary form of steroid used in most of the countries participating in the trial — but we were left with the strong impression that he would personally have preferred to see dexamethasone being used in this trial.

We have dealt separately with a report from Australia on the use of the Mediterranean diet as a  strategy to prevent prostate cancer.

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