Male Breast Cancer Incidence
Male breast cancer is rare, representing approximately 1% of all breast cancer cases diagnosed in the United States each year. 1
Epidemiology and Risk Factors
Male breast cancer is a rare disease with specific epidemiological characteristics:
- The lifetime risk of breast cancer is about 1:1,000 for men, compared to approximately 1:8 for women 1
- In 2019, an estimated 2,670 new cases of breast cancer were diagnosed among men in the United States 1
- About 500 men were expected to die from breast cancer in the United States in 2019 1
- The average age of diagnosis is 67 years for men, which is approximately 5 years older than for women (62 years) 1
Key Risk Factors
Several factors increase the risk of breast cancer in men:
- Genetic predisposition (particularly BRCA2 mutations)
- Family history of breast cancer
- Black ethnicity
- Exposure to radiation to the breast or chest
- Hormonal imbalances (including Klinefelter's syndrome)
- Use of exogenous estrogen 1
Genetic Considerations
Genetic factors play a significant role in male breast cancer:
- 0-4% of men with breast cancer have mutations of the BRCA1 gene
- 4-16% have mutations of the BRCA2 gene
- Other genes such as CHEK2, PALB2, and PTEN also confer elevated breast cancer risk in men
- Overall, approximately 20% of male breast cancer patients may carry an identifiable inherited risk factor 1
Clinical Presentation and Diagnosis
Male breast cancer often presents differently than female breast cancer:
- Men typically have less breast tissue, making physical abnormalities more noticeable
- Despite this, male breast cancer is often detected at a later stage due to lack of awareness
- Suspicious findings warranting further evaluation include:
Diagnostic Approach
For men with suspected breast cancer:
- Diagnostic mammography or digital breast tomosynthesis is recommended as the initial imaging study for males ≥25 years with breast symptoms 2
- Ultrasound is indicated when mammogram findings are indeterminate or suspicious 2
- Core needle biopsy is recommended for suspicious or indeterminate findings 2
- Genetic counseling and germline genetic testing should be offered to all men diagnosed with breast cancer 1
Survival and Mortality
Male breast cancer carries a worse prognosis compared to female breast cancer:
- Overall survival rates are lower in men compared to women with breast cancer
- For men, the 5-year survival rate is approximately 77.6% compared to 86.4% for women 3
- Mortality differences persist even after accounting for clinical characteristics, treatment factors, and access to care 3
- Recent trends show that breast cancer mortality has declined for both men and women, but the improvement has been greater for women than for men 4
Treatment Considerations
Treatment approaches for male breast cancer are largely extrapolated from female breast cancer management:
- Men with hormone receptor-positive breast cancer should be offered tamoxifen for an initial duration of five years 1
- Those with contraindications to tamoxifen may be offered a gonadotropin-releasing hormone agonist/antagonist plus aromatase inhibitor 1
- Targeted systemic therapy may be used with the same indications as for women 1
- Genetic testing results may identify treatment opportunities for patients with metastatic disease (e.g., PARP inhibitors) 1
Surveillance Recommendations
For men with a history of breast cancer:
- Ipsilateral annual mammogram should be offered to men treated with lumpectomy regardless of genetic predisposition
- Contralateral annual mammogram may be offered to men with a history of breast cancer and a genetic predisposing mutation
- Breast MRI is not recommended routinely 1
Male breast cancer remains an understudied disease with treatment approaches largely derived from female breast cancer research. The higher mortality rates in men highlight the need for increased awareness and male-specific research to improve outcomes.