title: Antiandrogen therapy in metastatic male breast cancer: results from an updated analysis in an expanded case series.
abstract: Male breast cancer is a rare disease treated as hormone receptor-positive female breast cancer. The characterization of breast cancer at the molecular level has lately revealed gender-related differences. As the androgen receptor is emerging as a potential oncogenic driver in male breast cancer, we analyzed efficacy data from metastatic patients treated with antiandrogens. We evaluated the activity of cyproterone acetate, either as a monotherapy or combined with a GnRH analog, in 36 metastatic male breast cancer patients. Fourteen patients were treated with cyproterone acetate as monotherapy and 22 patients with complete androgen blockade. We recorded 4 complete responses and 15 partial responses, for an overall response rate of 52.8 % (95 % CI, 36.5-69.4). Stable disease was reported in 11 patients. Median PFS was 8.9 months (95 % CI, 6.1-11.7), and median OS was 24.3 months (95 % CI, 22.5-26.1). Data on androgen receptor expression were available for 7 patients. All the 4 patients with androgen receptor-expressing tumors had a clinical benefit, including a patient with an estrogen receptor-negative disease. Conversely, none of the 3 patients with androgen receptor-negative tumors had a tumor response. Antiandrogen-based therapy showed efficacy in metastatic male breast cancer patients. Our results encourage considering antiandrogens in the therapeutic continuum, especially if supported by androgen receptor expression.
authors.affiliation: Division of Medical Oncology B, "Regina Elena" National Cancer Institute, Via Elio Chianesi 53, 00144, Rome, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Di Lauro
authors.forename: Patrizia
authors.initials: P
authors.lastname: Vici
authors.forename: Maddalena
authors.initials: M
authors.lastname: Barba
authors.forename: Laura
authors.initials: L
authors.lastname: Pizzuti
authors.forename: Domenico
authors.initials: D
authors.lastname: Sergi
authors.forename: Massimo
authors.initials: M
authors.lastname: Rinaldi
authors.forename: Anna
authors.initials: A
authors.lastname: Di Benedetto
authors.forename: Isabella
authors.initials: I
authors.lastname: Sperduti
authors.forename: Abeer M
authors.initials: AM
authors.lastname: Shaaban
authors.forename: Valerie
authors.initials: V
authors.lastname: Speirs
authors.forename: Marcella
authors.initials: M
authors.lastname: Mottolese
authors.forename: Ruggero
authors.initials: R
authors.lastname: De Maria
authors.forename: Marcello
authors.initials: M
authors.lastname: Maugeri-Saccà
mesh_terms: D000328:Adult; D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use*; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D018567:Breast Neoplasms, Male / Q000188:drug therapy* / Q000401:mortality; D017373:Cyproterone Acetate / Q000627:therapeutic use*; D018572:Disease-Free Survival; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011944:Receptors, Androgen / Q000096:biosynthesis; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: C410798:AR protein, human; D000726:Androgen Antagonists; D018931:Antineoplastic Agents, Hormonal; D011944:Receptors, Androgen; D017373:Cyproterone Acetate