Optimal prophylactic and definitive therapy for bicalutamide-induced gynecomastia: results of a meta-analysis

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 gynecomastia in most patients, which often results in treatment discontinuation. Optimal therapy for these breast events is not known so far. We undertook a meta-analysis to assess the efficacy of various treatment options for bicalutamide-induced gynecomastia.

METHODS

The medline, cancerlit, and Cochrane library databases were searched and the Google search engine was used to identify prospective and retrospective controlled studies published in English from January 2000 to December 2010 comparing prophylactic or curative treatment options with a control group (no treatment) for pca patients who developed bicalutamide-induced gynecomastia. Radiotherapy-induced cardiotoxicity was also evaluated.

RESULTS

The search identified nine controlled trials with a total patient population of 1573. Pooled results from prophylactic trials showed a significant reduction of gynecomastia in pca patients treated with prophylactic tamoxifen 20 mg daily (odds ratio: 0.06; 95% confidence interval: 0.05 to 0.09; p = 0.09), and pooled results from treatment trials showed a significant response of gynecomastia to definitive radiotherapy (odds ratio: 0.06; 95% confidence interval: 0.01 to 0.24; p < 0.0001). Aromatase inhibitors and weekly tamoxifen were not found to be effective as prophylactic and curative options. For the radiotherapy, skin-to-heart distance was found to be an important risk factor for cardiotoxicity (p = 0.006). A funnel plot of the meta-analysis showed significant heterogeneity (Egger test p < 0.00001) because of low sample size.

CONCLUSIONS

Our meta-analysis suggests using prophylactic tamoxifen 20 mg daily as the first-line preventive measure and radiotherapy as the first-line treatment option for bicalutamide-induced gynecomastia. Aromatase inhibitors and weekly tamoxifen are not recommended.

An open, randomised, multicentre, phase 3 trial comparing the efficacy of two tamoxifen schedules in preventing gynaecomastia induced by bicalutamide monotherapy in prostate cancer patients

BACKGROUND

Bicalutamide monotherapy is a valuable option for prostate cancer (PCa) patients who wish to avoid the consequences of androgen deprivation; however, this treatment induces gynaecomastia and mastalgia in most patients. Tamoxifen is safe and effective in preventing breast events induced by bicalutamide monotherapy without affecting antitumor activity, but possible interference between bicalutamide and tamoxifen remains a matter of concern. To reduce the exposure to tamoxifen, we considered the putative advantages of weekly administration.

OBJECTIVE

To compare the efficacy of two different schedules of tamoxifen in preventing breast events. Toxicity, prostate-specific antigen behaviour, and sexual-functioning scores were also evaluated.

DESIGN, SETTING, AND PARTICIPANTS

This was a noninferiority trial. From December 2003 to February 2006, 80 patients with localised/locally advanced or biochemically recurrent PCa who were also candidates for bicalutamide single therapy were randomised to receive two different schedules of tamoxifen: daily (n=41) and weekly (n=39). Median follow-up was 24.2 mo.

INTERVENTION

Daily bicalutamide (150 mg) plus daily tamoxifen 20mg continuously (daily group) or the same but with tamoxifen at 20mg weekly after the first 8 wk of daily treatment (weekly group). Three patients in the weekly group and one in the daily group were discontinued for adverse events.

MEASUREMENTS

For gynaecomastia, we used ultrasonography. For mastalgia and sexual functioning, we used questionnaires.

RESULTS AND LIMITATIONS

Gynaecomastia developed in 31.7% of patients in the daily group and in 74.4% of patients in the weekly group (p<0.0001), and it was more severe in patients who switched to weekly tamoxifen (p=0.001). Mastalgia occurred in 12.2% and 46.1% of patients, respectively (p=0.001). There were no major differences among treatment schedules relative to sexual functioning scores and incidence and severity of adverse events. No differences between groups in PSA behaviour and disease progression have been detected so far.

CONCLUSIONS

This study demonstrated that tamoxifen 20mg/wk is inferior to tamoxifen 20mg/d in preventing the incidence and severity of bicalutamide-induced breast events. The safety and efficacy of tamoxifen at the common daily dose of 20mg for the prophylaxis of bicalutamide-induced breast events were confirmed.

The social context for psychological distress from iatrogenic gynecomastia with suggestions for its management

INTRODUCTION

Gynecomastia (breast development in males) is a side effect of androgen deprivation therapy (ADT) for prostate cancer (PCa). Medical interventions to prevent or treat gynecomastia carry risk of additional detrimental side effects. However, untreated gynecomastia can be physically uncomfortable and psychologically distressing. Shame from gynecomastia can lead patients to stop otherwise beneficial exercise.

AIMS

Our first aim is to explore the social context for gynecomastia and how it is interpreted by men with the condition, as well as by others, both male and female. Subsequently, we use our understanding of why gynecomastia is psychologically distressing to propose psychosocial interventions that could help men accept this side effect of ADT.

METHODS

We draw on academic literature, media accounts, and web-based testimonials from men with gynecomastia, to understand how gynecomastia is perceived by both patients and the medical community. We examine these resources in light of gynecomastia's impact on sex roles, sexuality, and gender identity issues.

MAIN OUTCOME MEASURES

By exploring what breasts in a male mean to the individual, we produce an understanding of the social context for distress from gynecomastia. From this understanding, we derive hypotheses about who might be most distressed from gynecomastia and strategies for alleviating this distress.

RESULTS

The shame and stigma of gynecomastia is linked to the objectification of women. We suggest that men fear that their breasts will marginalize and subordinate them within gender hierarchies. There is little evidence that breasts on a male erotically attract either men or women. Novel options for living with gynecomastia are contrasted with medicalized strategies including mastectomy.

CONCLUSION

Assessment instruments need to be developed to identify patients most likely to experience distress from gynecomastia and seek out medical interventions. Surgical, radiological, or pharmacological interventions may not be universally necessary if greater acceptance of gynecomastia is made available through psychosocial support programs. For example, PCa patients may learn to accept gynecomastia through reconceptualizing their breasts as autoerotic. Support programs modeled on those of the breast cancer community, including Encore and dragon boat racing, may also help to build communities to serve patients with gynecomastia while defending individuals against shame, isolation, and loss of self-esteem.