Breast cancer is one of the most common malignancies among women worldwide, leading to a widespread societal and, in some cases, medical perception that it is a disease exclusive to females. Although male breast cancer accounts for no more than 1% of all reported breast cancer cases, mortality rates associated with the disease in men are relatively high compared with those in women. Recent studies attribute this disparity in outcomes to diagnostic delays, limited public awareness, and the absence of routine screening programs for men. In recognition of Breast Cancer Awareness Month (October 2026), this scientific article aims to highlight the biological, anatomical, and pathogenic characteristics of male breast cancer, examine the genetic and hormonal predisposing factors, and review established diagnostic and treatment strategies. 1. Introduction International health organizations designate October as Breast Cancer Awareness Month, a campaign that focuses predominantly on women's health. However, this predominantly female-centered focus has indirectly contributed to the marginalization of another patient population: men with breast cancer. Anatomically, both sexes possess similar breast tissues at birth, consisting of rudimentary milk ducts, connective tissue, and adipose tissue. At puberty, elevated estrogen levels in females stimulate the development of the mammary glands and ducts, whereas higher testosterone levels in males limit this growth. Nevertheless, glandular ducts persist in men and remain susceptible to cellular changes that may develop into malignant tumors under appropriate biological and genetic conditions. 2. Pathogenic Factors and Predisposing Risk Factors The development of male breast cancer is associated with an imbalance between estrogen and testosterone levels or the presence of inherited genetic mutations. Genetic factors - BRCA2 and BRCA1 mutations: Inherited mutations in the BRCA2 gene are among the strongest genetic risk factors for male breast cancer, increasing the estimated lifetime risk to approximately 6%–8%. BRCA1 mutations are also associated with an increased risk, although the increase is generally smaller. - Klinefelter syndrome: This chromosomal condition (47,XXY) is characterized by low testosterone levels and elevated gonadotropin levels, increasing the risk of breast cancer by approximately 20–50 times compared with unaffected males. Environmental and physiological hormonal disorders - Absolute or relative hyperestrogenism: Elevated estrogen levels may result from chronic liver diseases, such as liver cirrhosis, which impairs estrogen metabolism, or from severe obesity, in which the aromatase enzyme in adipose tissue converts androgens into estrogens. - Radiation exposure: Previous therapeutic radiation to the chest region, such as radiation therapy for certain cases of lymphoma, may increase the risk. 3. Histopathological and Clinical Characteristics Predominant histological type: Invasive ductal carcinoma (IDC) accounts for more than 85% of male breast cancer cases. Lobular carcinomas are common in women but are extremely rare in men because the mammary lobules are incompletely developed. Hormone receptor status: More than 90% of male breast cancers are positive for estrogen and progesterone receptors (ER+/PR+), compared with a hormone receptor positivity rate of approximately 70%–80% in women. Clinical presentation: The disease most commonly presents as a firm, painless mass beneath the nipple or areola. Nipple retraction or bloody nipple discharge may also occur. In women, breast masses may arise in different quadrants of the breast and may sometimes be detected through screening mammography before becoming clinically apparent. 4. Diagnostic and Therapeutic Challenges 1. Diagnostic delay Delayed medical consultation represents one of the major challenges in male breast cancer. The interval between symptom onset and diagnosis may extend over several months. This delay is often attributable to limited awareness and the misconception that a breast lump is merely benign gynecomastia or a fatty cyst. Consequently, the disease may be diagnosed at advanced stages, such as stage III or IV, with an increased likelihood of axillary lymph node involvement. 2. Diagnostic methods Diagnostic methods are broadly similar in both sexes and rely on the triple assessment approach, which includes: - Clinical examination of the chest and axillary regions. - Imaging studies, including mammography and breast ultrasonography. - Core needle biopsy to confirm the histological type and determine biological receptor status. 3. Treatment protocols - Surgery: Modified radical mastectomy or total mastectomy is among the standard surgical options because men have a relatively small volume of breast tissue compared with women, in whom breast-conserving surgery is more commonly performed. - Hormonal therapy: Given the high prevalence of hormone receptor positivity, tamoxifen is a cornerstone of adjuvant endocrine therapy and is associated with improved survival outcomes. - Chemotherapy and radiotherapy: These treatments are selected according to tumor size, patient age, lymph node status, and the tumor's genetic characteristics. 5. Recommendations and Conclusion The scientific answer to the medical question is clear: breast cancer is not a disease exclusive to women. Although its incidence in men is low, its clinical burden and potential severity warrant equivalent attention from researchers and the wider community. Recommendations - Enhancing health awareness: Include male breast health in annual educational campaigns and emphasize the importance of seeking medical advice when any change in the chest or nipple region is noticed. - Genetic counseling: Refer men diagnosed with breast cancer for genetic counseling and testing to identify BRCA2 mutations, which may help guide early risk assessment and preventive strategies for their first-degree relatives. - Clinical studies: Encourage the inclusion of men in clinical trials investigating breast cancer treatments to reduce exclusive reliance on extrapolating findings from studies designed for women. Al-Mustaqbal University – The First University in Iraq