Female to Male ratio of breast cancer is 100:1. Carcinoma of the male breast has many similarities to breast cancer in women, but the diseases have different genetic and pathologic features. Only BRCA2 mutations confer a significant risk to men, unlike women where both BRCA1 and BRCA2 mutations can cause breast cancer. Noninvasive carcinomas in men are all low- to intermediate-grade ductal carcinoma in situ; pure lobular carcinoma in situ is extremely rare. Most invasive carcinomas are infiltrating ductal, with lobular carcinoma representing only about 1% of invasive disease.
Men have higher rates of estrogen and progesterone positivity than do women but similar percentages of c-erbB-2, p53, cyclin D1, and EGFR over expression. Men may be more likely to have tumors that over express bcl-2, but the clinical significance of this finding is not clear.
MBC accounts for 1% of all breast cancer, with <1% of all annual deaths in men. Median age at onset is between 65-67 years. Incidence varies from 0.1- 3.4 cases per 100000 human years
- Relative estrogen excess or lack of androgen
- Never married
- Previous benign breast diseases
- H/o testicular pathology
- Liver disease
- Family h/o BC
- Prior chest wall irradiation
Male breast cancer is usually unilateral, bilateral seen in <1% cases
- Majority of MBC presents as painless firm subareolar mass
- Nipple discharge
- Nipple retraction, ulceration, fixation to surrounding structures
- Axillary adenopathy
- Breast abscess
- Metastasis to breast
85% of MBC is invasive ductal carcinoma, lobular carcinoma is rare or not reported. DCIS accounts for an average of 7%. 91% of tumors are ER positive and 96% are PR positive. Molecular Markers for male breast cancer are Androgen Receptor (95%), Bcl2 (95%), Her2 (29%), CyclinD1 (58%) and p53 in 21%.
For localized disease, modified radical mastectomy is the preferred surgical approach. Sentinel node biopsy is accurate and feasible in male .
As in women, axillary lymph node status, tumor size, histologic grade, and hormone receptor status have been shown to be significant prognostic factors in MBC. Lymph node involvement is the most important negative prognostic factor for breast carcinoma in men
A benefit of adjuvant chemotherapy in men as similar as benefit for adjuvant chemotherapy in women. Same guidelines in men as in women ( node-positive disease or primary tumors that are larger than 1cm). The 5-year survival rate among treated patients was 80%, which was significantly better than the survival rates among historical controls
Adjuvant Hormonal Therapy
Although the evidence is limited, most studies point to a benefit from both adjuvant tamoxifen and chemotherapy. Given the known benefit of adjuvant therapy in women, men also be offered adjuvant therapy using the same guidelines that are the standard of care for women. Because men have high rates of response to additive hormonal therapy, this approach is recommended for first-line treatment in hormone receptor–positive disease.
Tamoxifen is the most accepted front-line additive therapy. Selective aromatase inhibitors (anastrozole and letrozole) have been approved for first-line treatment of metastatic breast cancer in women, but there are no published reports of responses in men. The optimal length of therapy in women is 5 years; and also similar in MBC
Adjuvant Radiation Therapy
There is no evidence that adjuvant radiation therapy after mastectomy improves survival, although men may have a higher risk for internal mammary lymph node metastases and in theory could benefit from internal mammary radiation therapy.
Postmastectomy RT in MBC decreases loco-regional recurrence but no impact on OS. A recent retrospective review of studies suggested that the indications are similar like FBC
Therapy for Metastatic Disease
Hormonal therapy has been the mainstay of treatment for metastatic carcinoma of MBC. Initial hormonal therapies were ablative orchiectomy, adrenalectomy, and hypophysectomy. Response rate is 55% for orchiectomy, 80% for adrenalectomy, and 56% for hypophysectomy. Additive hormonal therapy is reversible, avoids surgical morbidity and mortality, and is psychologically more acceptable to most men than orchiectomy
Systemic chemotherapy, is usually reserved for second-line therapy because most men will respond to hormonal manipulation. One study directly compared chemotherapy with hormonal therapy and found superior response rates in patients treated with hormonal therapy. Chemotherapy, however, can offer significant palliation to men in whom hormonal therapy has failed or those with hormone receptor–negative disease
Survival and Prognosis
- The 10-year survival rate for patients with histologically node-negative disease was 84% compared with 44% for 1-3+ve nodes, and 14% for 4or more +ve nodes
- MBC 5-year crude survival rates by tumor size were 85% for tumors measuring less than 2 cm in diameter, 63% (2 to 5 cm), and 51% tumors (>5 cm).
- 5-year survival based on histologic grade of tumor (grade 1, 76%; grade II, 66%; and grade III, 43%).
- Overall 5-year survival rates are 55% to 100% for stage I, 41% to 78% for stage II, 16% to 57% for stage III, and 0% to 14% for stage IV disease