Gynecomastia and/or mastodynia is a common medical problem in patients receiving antiandrogen (bicalutamide or flutamide) treatment for prostate cancer; up to 70% of these patients result to be affected; furthermore, this can jeopardise patients' quality of life.

To systematically review the quality of evidence of the current literature regarding treatment options for bicalutamide-induced gynecomastia, including efficacy, safety and patients' quality of life.

The PubMed, Medline, Scopus, The Cochrane Library and SveMed+ databases were systematically searched between January 1, 2000 and December 31, 2014. All searches were undertaken between January and February 2015. The search phrase used was:"gynecomastia AND treatment AND prostate cancer". Two reviewers assessed 762 titles and abstracts identified. The search and review process was done in accordance with the PRISMA statement. The PICOS (patients, intervention, comparator, outcomes and study design) process was used to specify inclusion criteria. Quality of evidence was rated according to GRADE.

Primary outcomes were: treatment effects, number of complications and side effects. Secondary outcome was: Quality of Life.

Eleven studies met the inclusion criteria and are analysed in this review. Five studies reported pharmacological intervention with tamoxifen and/or anastrozole, either as prophylactic or therapeutic treatment. Four studies reported radiotherapy as prophylactic and/or therapeutic treatment. Two studies compared pharmacological treatment to radiotherapy. Most of the studies were randomized with varying risk of bias. According to GRADE, quality of evidence was moderate to high.

Bicalutamide-induced gynecomastia and/or mastodynia can effectively be managed by oral tamoxifen (10-20 mg daily) or radiotherapy without relevant side effects. Prophylaxis or therapeutic treatment with tamoxifen results to be more effective than radiotherapy.