Endocrine Abstracts

Objective: Bicalutamide is approved as an adjuvant to primary treatments (radical prostatectomy or radiotherapy) or as monotherapy in men with locally advanced, nonmetastatic prostate cancer (PCa); however, this treatment induces gynaecomastia in most of patients, which results in treatment withdrawal. Optimal therapy for these breast events is not known so far. We conducted a meta-analysis to assess the efficacy of different treatment options for bicalutamide induced gynaecomastia.

Patients and methods: The Medline, CANCERLIT, Cochrane library database and Google search engine were searched to identify prospective and retrospective controlled studies published in English from January 2000 to December 2010 comparing prophylactic or curative treatment options with control group (no treatment) for PCa patients who developed bicalutamide induced gynaecomastia. Further, radiotherapy induced cardiotoxicity was evaluated.

Results: Nine controlled trials with a total patient population of 1573 were identified. Pooled results from prophylactic trials showed a significant reduction of gynaecomastia in PCa patients treated with prophylactic tamoxifen 20 mg daily dose (odds ratio 0.06 95% CI 0.05–0.09 (P 0.09)) and pooled results from treatment trials showed significant response in gynaecomastia with definitive radiotherapy (odds ratio 0.06 95% CI 0.01–0.24 (P<0.0001)). Aromatase inhibitors and weekly tamoxifen were not found effective as prophylactic and curative options. For the radiotherapy, skin to heart distance (SHD) was found important risk factor cardiotoxicity (P 0.006). The resultant funnel plot of meta-analysis showed significant heterogeneity (Egger test P<0.00001) due to low sample size.

Conclusion: Our meta-analysis suggests use of prophylactic tamoxifen 20mg daily as first line preventive measure for bicalutamide induced gynaecomastia and radiotherapy as first line treatment option shall be considered for patients who are not candidates for tamoxifen. The aromatase inhibitors and weekly tamoxifen are not recommended.

Keywords: Meta-analysis, bicalutamide induced gynaecomastia, prostate cancer.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.