What is correct regarding male breast cancer?

Male Breast Cancer: Key Characteristics and Management

Male breast cancer is typically hormonally dependent, with over 90% of cases being estrogen receptor-positive, and tamoxifen is the standard adjuvant endocrine therapy for these patients. 1

Epidemiology and Clinical Presentation

• Male breast cancer accounts for approximately 1% of all breast cancers 1
• The average age of diagnosis is 67 years for men, which is 5 years older than for women 1
• Risk factors include:
  • Family history of breast cancer
  • BRCA2 mutations (strongest genetic risk factor)
  • Other genetic mutations (BRCA1, CHEK2, PALB2)
  • Klinefelter's syndrome and other conditions associated with hyperestrogenism
  • Exposure to radiation
  • Exogenous estrogen use

Hormonal Dependence

• Male breast cancer is predominantly hormone receptor-positive:
  • 99% are estrogen receptor (ER) positive
  • 81% are progesterone receptor (PR) positive 1
• This strong hormonal dependence makes endocrine therapy the mainstay of systemic treatment

Clinical Presentation

• Most commonly presents as a palpable mass
• Other presentations include:
  • Skin or nipple retraction
  • Nipple discharge (though bloody discharge is not typical)
  • Advanced stage at presentation (larger tumor size and higher probability of nodal metastases) 1

Treatment Approach

• Endocrine Therapy:

  • Tamoxifen is the standard adjuvant endocrine therapy for hormone receptor-positive male breast cancer 1
  • Initial duration of treatment is 5 years
  • Men with high recurrence risk who tolerate tamoxifen well may be offered an additional 5 years of therapy
  • For men with contraindications to tamoxifen, a gonadotropin-releasing hormone agonist/antagonist plus an aromatase inhibitor is recommended

• Targeted Therapy:

  • Targeted therapies based on HER2, PD-L1, PIK3CA, and germline BRCA mutation status may be used with the same indications as in women 1

Surveillance

• Annual ipsilateral mammogram for men treated with lumpectomy
• Contralateral annual mammogram may be offered to men with genetic predisposing mutations
• Breast MRI is not routinely recommended 1

Genetic Testing

• All men with breast cancer should be offered genetic counseling and testing for germline mutations 1

Common Pitfalls in Management

1. Underutilization of tamoxifen: Despite the strong evidence supporting its use, studies show only about 77% of men with ER-positive breast cancer receive adjuvant endocrine therapy 1
2. Using aromatase inhibitors alone: This approach is not recommended as it has been associated with inferior survival compared to tamoxifen in men 1
3. Delayed diagnosis: Men often present with more advanced disease due to lack of awareness and screening

Based on the evidence presented, the correct answer is B. Male breast cancer is typically hormonally dependent, with the vast majority of cases being estrogen and progesterone receptor positive, making endocrine therapy with tamoxifen the standard treatment approach.