Men and Breast Cancer

Pink ribbons, fundraising campaigns, and awareness initiatives have made breast cancer a well-recognized cause. While breast cancer is more common in women with more than 2.26 million new cases in 2020 [1], the impact on men is no less profound. In the US, according to the American Cancer Society, 28,000 men will be diagnosed and approximately 530 will die in 2023 [2] (more information on diagnosis and screening in our previous post). This article will explore the often-overlooked topic of breast cancer in men, their risk factors, and the crucial importance of early detection and awareness.

Everyone has breast tissue consisting of milk-producing glands, ducts that carry the milk to the nipples, and fat [3,4]. However, during puberty, women grow more glands and milk ducts - where most of the cancers develop [3,5] - while men have mainly fat and fibrous breast tissue. These anatomical differences might be a contributing factor to the higher incidence of breast cancer in women, however it is a complex interaction of different factors like hormones, genetics, and environment that ultimately leads to the sex disparity in breast cancer cases. Some of the risk factors that may increase a man’s likelihood of breast cancer are [4,6-7]:

• Gene mutations can be caused by smoking and radiation, or from the BRCA1 and BRCA2 genes that are passed down across generations. These genes make proteins that repair damaged DNA and prevent abnormal growth. Having a mutated gene may interfere with this process and increase the risk of cancer [6].

• High levels of estrogen in the body due to liver disease, obesity, or hormonal treatments (more information on how these affect estrogen levels here).

• Klinefelter syndrome. This syndrome occurs when males are born with two copies of the X chromosome and one copy of the Y chromosome (XXY) [8]. Because of the Y chromosome, people with this syndrome develop stereotypical male characteristics and genitals. However, the extra X chromosome often leads to smaller testes that produce a reduced amount of testosterone and can cause a hormonal imbalance.

Even though there are fewer men diagnosed with breast cancer, they usually have poorer outcomes compared to women [9,10]. Psychological and social factors, including stigma and lack of support networks, often discourage early diagnosis. However, it is crucial for men to get examinations as well, as mentioned in the previous post, the survival rate reaches 99% when breast cancer is detected in the first 5 years [11]. Moreover, the focus of breast cancer research and clinical trials on women limits data on effective treatments for male breast cancer [10].

Nowadays, discussion surrounding men’s health predominantly focuses on conditions like prostate cancer or heart disease, however, breast cancer in men is also worth mentioning. The disparities in awareness, delayed diagnoses, and limited research highlights the need for a better understanding of this disease in men. It is imperative to raise awareness and eliminate misconceptions about breast cancer to ensure this condition is also diagnosed in men at its most treatable stages and more research is done to develop sex-specific treatments.

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Written by: María

Edited by: Natasha

BioDecoded is a volunteer group committed to sharing accurate scientific information. We cannot offer any specific health advice. If you have any questions about this topic or would like to learn more, please comment below, or send us your questions.

References:

1. Breast cancer statistics (2022). World Cancer Research Fund International. Available at: https://www.wcrf.org/cancer-trends/breast-cancer-statistics/ (Accessed: 23 October 2023).

2. Cancer facts and figures (2023). American Cancer Society. Available at: https://www.cancer.org/content/dam/cancer-org/research/cancer-facts-and-statistics/annual-cancer-facts-and-figures/2023/2023-cancer-facts-and-figures.pdf (Accessed: 23 October 2023).

3. What Is Breast Cancer in Men? (2018). American Cancer Society. Available at: https://www.cancer.org/cancer/types/breast-cancer-in-men/about/what-is-breast-cancer-in-men.html (Accessed: 23 October 2023).

4. Male breast cancer (2023). Mayo Clinic. Available at: https://www.mayoclinic.org/diseases-conditions/male-breast-cancer/symptoms-causes/syc-20374740 (Accessed: 23 October 2023).

5. Feng, Y., et al. (2018) Breast cancer development and progression: Risk factors, cancer stem cells, signaling pathways, genomics, and molecular pathogenesis. Genes & Diseases 12;5(2): 77-106. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6147049/

6. What Causes Breast Cancer in Men? (2018). American Cancer Society. Available at: https://www.cancer.org/cancer/types/breast-cancer-in-men/causes-risks-prevention/what-causes.html (Accessed: 23 October 2023).

7. Male Breast Cancer Treatment (2022). National Cancer Institute. Available at: https://www.cancer.gov/types/breast/patient/male-breast-treatment-pdq#_69 (Accessed: 23 October 2023).

8. Klinefelter syndrome (2023). MedlinePlus Genetics. Available at: https://medlineplus.gov/genetics/condition/klinefelter-syndrome/ (Accessed: 23 October 2023).

9. Anderson, W. F., et al. (2010). “Male Breast Cancer: A Population-Based Comparison With Female Breast Cancer”. Journal of Clinical Oncology, 28(2), 232–239. Available at: https://ascopubs.org/doi/10.1200/JCO.2009.23.8162

10. Wang F, et al (2019). “Overall Mortality After Diagnosis of Breast Cancer in Men vs Women”. JAMA Oncology 5(11):1589–1596. Available at: https://jamanetwork.com/journals/jamaoncology/fullarticle/2751525

11. Cancer Screening Guidelines: Detecting Cancer Early (2023). American Cancer Society. Available at: https://www.cancer.org/cancer/screening/american-cancer-society-guidelines-for-the-early-detection-of-cancer.html (Accessed: 24 October 2023).