What is true about male breast cancer?

Male Breast Cancer: Key Characteristics

Male breast cancer is most strongly associated with BRCA2 gene mutations, not BRCA1 gene mutations, and is predominantly hormone receptor-positive. 1

Genetic Associations

• BRCA2 gene mutations are found in 4-16% of men with breast cancer, while BRCA1 mutations are much less common, occurring in only 0-4% of cases 1
• The cumulative risk of breast cancer by age 70 for male BRCA2 mutation carriers is 6.8%, compared to only 1.2% for male BRCA1 mutation carriers 2
• Other genetic mutations associated with male breast cancer include CHEK2, PALB2, and PTEN, collectively accounting for approximately 20% of cases 1, 3

Histopathological Features

• Male breast cancer is predominantly of ductal origin (85-90% invasive ductal carcinomas), with lobular carcinomas being exceptionally rare 3
• Therefore, it is incorrect that male breast cancer can only be of ductal origin, as other histological types do occur, though less frequently 3
• About 5-10% of male breast cancers are ductal carcinoma in situ 3

Hormone Receptor Status

• Approximately 75% of male breast cancers express estrogen and progesterone receptors, with positivity increasing with patient age 3
• Male breast cancer is predominantly hormone receptor-positive, making endocrine therapy highly effective in treatment 4
• This contradicts the statement that male breast cancer is "seldom hormone receptor positive" 4, 3

Age at Diagnosis

• The average age of diagnosis for male breast cancer is 67 years, which is approximately 5 years older than for women (62 years) 1, 4
• Incidence rates rise steadily with age in men, similar to women, but with a later onset 4
• This refutes the claim that male breast cancer develops at a much younger age than female breast cancer 1

Treatment Implications

• Due to the high prevalence of hormone receptor positivity, tamoxifen is the standard adjuvant therapy for hormone receptor-positive male breast cancer 4, 5
• Published results show tamoxifen is effective for the palliative treatment of male breast cancer, with a 50% objective response rate 5
• Genetic counseling and germline genetic testing should be offered to all men with breast cancer due to the high prevalence of hereditary mutations 1, 4

Clinical Considerations

• Male breast cancer typically presents as a retroareolar mass, with the majority of tumors seen retromamillarly 3
• Risk factors include black ethnicity, radiation exposure to chest, genetic predisposition, and conditions associated with hyperestrogenism (e.g., Klinefelter's syndrome) 4
• Surveillance recommendations include ipsilateral annual mammogram for men with a history of breast cancer treated with lumpectomy, and consideration of contralateral mammogram for those with genetic predisposing mutations 4

Based on the evidence presented, the correct answer is A. Male breast cancer is associated with the BRCA1 gene mutation is FALSE. While BRCA1 mutations can increase risk, BRCA2 mutations are much more strongly associated with male breast cancer.