Biological differences between genders may explain why men more likely to develop cancer

ROCKVILLE, Md. — Men may be more at risk for cancer than women due to biological differences, rather than lifestyle factors such as smoking and drinking, according to new research.

Researchers say understanding the reasons for differences in cancer risk between the sexes could help to improve prevention and treatment, especially for at-risk men.

In 2019 alone, the CDC reports there were over 888,000 new cases of cancer among men. There were more than 863,000 among women.

“Our results show that there are differences in cancer incidence that are not explained by environmental exposures alone. This suggests that there are intrinsic biological differences between men and women that affect susceptibility to cancer,” says Dr. Sarah Jackson of the National Cancer Institute in a media release.

Publishing their work in the journal Cancer, the team assessed differences in cancer risk for each of the 21 cancer sites in the body among 171,274 males and 122,826 females between 50 and 71 years-old who participated in a diet and health study between 1995 and 2011.

Which cancers do men need to look out for?

During that time, there were 17,951 new cancers in men and 8,742 in women. There were fewer cases for men only for thyroid and gallbladder cancers and the risks were 1.3 to 10.8 times higher in men than women at other sites in the body. Men were at higher risk for esophageal (10.8 times higher), larynx (3.5 times higher), gastric cardia (3.5 times higher), and bladder cancer (3.3 times higher) than their female counterparts.

Men also had a higher risk of most cancers even after taking into account a wide range of lifestyle factors and exposure to carcinogens. In fact, researchers found that these factors only accounted for a modest proportion of most cancers, ranging from 11 percent for esophageal to 50 percent for lung cancer.

The findings suggest that biological differences such as physiological, immunological, genetic, or others play a major role in forming susceptibility to cancer between the sexes. In an accompanying editorial to the study, the authors explained how to address the disparity.

“Strategically including sex as a biological variable should be enforced along the whole cancer continuum from risk prediction and cancer primary prevention, cancer screening and secondary prevention, to cancer treatment and patient management,” the study authors write.

“Examining and addressing sex disparities in cancer and other diseases is an ongoing quest. Bench to bedside translational studies which effectively transform the existing research findings into clinical practice is a scalable means within easy reach to achieve precision medicine and will mitigate—and may ultimately eradicate—sex disparities in cancer.”

South West News Service writer Danny Halpin contributed to this report.

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