#HimToo: Fat and Male Breast Cancer

While rare compared to female breast cancer, the incidence of male breast cancer (MBC) has increased in the last few decades, no doubt coincident with the ever-growing obesity epidemic. 

It has long been known that obesity and the risk of many types of cancer are linked, and although obesity is not considered an established risk factor for MBC specifically, there are parallel trends in the increases in both the incidence of MBC and male obesity. 

Excluding underlying genetics, one of the risk factors associated with MBC is high estrogen levels. Consider the following:

1. Adipose tissue (fat) contains aromatase (one of several enzymes found in fat), which converts male hormones (testosterone) to female hormones (estrogen). The fatter the man, the higher, the increased levels of estrogen.
2. Although women have more, men do have a small amount of breast tissue. They also have receptors on the cell surface of that tissue that recognize the female hormone and uses them to grow.
3. This leads to gynecomastia (male breasts), which affects an estimated 65% of males and which is considered a risk factor for MBC development by as much as 10-fold as compared to men of healthy weight.
4. The conversion of testosterone to estrogen suppresses the release of luteinizing hormone, which leads to a reduction in testosterone production. As a result, estrogen levels are significantly higher in older men than post-menopausal women. Thus, a man’s excess fat (more estrogen) coupled with declining levels of testosterone in the ageing male, provides a hormone environment which helps promote the genesis of MBC in obese men.

Another risk factor for MBC is cholesterol. Cholesterol can be converted into another molecule that mimics estrogen’s activity. Men who are obese tend to have much higher levels of cholesterol, and because of that they have more of the compound that mimics estrogen within their bodies, which boosts cancer growth.

Breast cancer in men is often diagnosed later than breast cancer in women. This may be because men are less likely to be suspicious of an abnormality in that area. In addition, their small amount of breast tissue is harder to feel — making it more difficult to catch these cancers early, and allowing tumors to spread more quickly to the surrounding tissues.

Gentlemen, obesity is a preventable condition, so take measures to reduce your risk of developing the disease.

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Additional reading: “I never knew men could get breast cancer” (October 30, 2018)

Here’s another great resource about male breast cancer from StoryMD:
https://storymd.com/journal/yj5ddee0nm-male-breast-cancer/page/ddv84i5544-male-breast-cancer