Review article: Epidemiology of male breast cancer. A meta‐analysis of published case‐control studies and discussion of selected aetiological factors

Abstract

Male breast cancer is a rare tumour in all parts of the world. About 1% of all breast cancers occur in men, but the male/female ratio is higher among black than among white populations. This effect can be seen in US cancer registries and even more markedly in African data. A positive correlation exists on a population scale between male breast cancer and prostate cancer. Seven case-control studies of male breast cancer are available, and a pooled analysis was conducted of the most commonly suspected risk factors. Male breast cancer appears to be associated with marital status: Mantel-Haenszel exposure odds ratio (EOR) for never married = 1.6; 95% confidence limits (CL) = 1.1, 2.3, religion (EOR for being Jewish = 2.1; 95% CL = 1.4, 3.2), previous breast pathology (EOR for positive history of benign breast disease = 2.7; 95% CL = 1.7, 4.2), gynaecomastia (EOR for positive history = 6.2, 95% CL = 3.4, 11.4), previous testicular pathology (EOR for positive history = 2.2; 95% CL = 1.5, 3.3), previous liver diseases (EOR for positive history = 1.6; 95% CL = 1.0, 2.4) and family history of breast cancer (EOR for first-degree relative with breast cancer = 2.5; 95% CL = 1.7, 3.7). No association is found with smoking history. Other potential risk factors such as reproductive history, education, occupation, anthropometric variables, association with various diseases, and specific exposures such as drug use, were not systematically evaluated in all studies and provide sometimes contradictory results, possibly due to small numbers of exposed subjects. Overall, the analytical epidemiology of male breast cancer presents similarities with the epidemiology of female breast cancer, with a potential role of factors related to hormonal status, relative hyperoestrogeny in men being potentially linked to increased risk of disease. Genetics may also play a role, with high risk linked to a familial history of breast cancer, and with a major risk in patients with Klinefelter's syndrome.

Multivariate Analysis of Prognostic Factors in Male Breast Cancer in Serbia

“…Therefore, after the necessary pathohistological analysis there is no sufficient tissue left for molecular and genetic researches. Risk factors for breast cancer development in male include positive family history for breast cancer, exposure to radiation and high temperatures, excessive alcohol consumption and states in which the level of hormone estrogen increases (Klinefelter's syndrome, gynecomastia and other) (Sasco et al, 1993;D'Avanzo and La Vecchia, 1995). In our study about 30% of male with breast cancer had positive family history for some cancer.…”

Risk factors for male breast cancer

“…Male breast cancer is extremely rare, representing less than 1% of all breast cancer and less than 0.1% of all cancer deaths in men Sasco et al, 1993). Consequently, epidemiological data are scant.…”

“…Some associations have been suggested with sociodemographic characteristics, including a direct gradient with social class (i.e. an increased risk in higher social classes) (Sasco et al, 1993), although this remains controversial (Lenfant-Pejovic et al, 1990;Thomas et al, 1992); with marital status, never married men being more frequently affected; and with religion, Jewish men being at highest risk (Mabuchi et al, 1985;Thomas et al, 1992;Sasco et al, 1993).…”

“…Previous breast or testicular disease and gynaecomastia have been related to male breast cancer, and associations are reported with orchiectomy, orchitis, testicular injury, late puberty and infertility (Sasco et al, 1993). Klinefelter's syndrome is substantially more common among male breast cancer patients (Casagrande et al, 1988;Sasco et al, 1993).…”

“…Klinefelter's syndrome is substantially more common among male breast cancer patients (Casagrande et al, 1988;Sasco et al, 1993).…”