New Studies Show High Prevalence in Cancer for Men Might Be Caused By Genetic Makeup

In an effort to demystify the high prevalence of cancer in men, researchers at the National Institutes of Health’s (NIH) National Cancer Institute examined data for 171,274 male and 122,826 female participants in the NIH-AARP Health and Diet study.

According to the data, biological differences between men and women are to blame for the imbalance rather than social or lifestyle elements like drinking and smoking, height and body mass index (BMI), physical activity, nutrition, and medical history.

Lead author Dr. Sarah S. Jackson said, “We predicted that these lifestyle factors weren’t the main reason that cancer incidence differed between men and women, but we were a bit shocked that for many diseases, these lifestyle factors accounted such a minor part of the difference.

21 cancer locations in the body were evaluated by researchers for the discrepancy. They discovered that 8,742 of the new cancer diagnoses were given to women and 17,951 to men.

The study indicates that “sex and, as a consequence, sex-related physiological variables are key drivers of cancer cases in the United States, in addition to recognized carcinogenic exposures.”

The authors state that knowing the sex-related biological mechanisms behind the male predominance in cancer in similar anatomical areas may have significant repercussions for etiology and prevention.

Cancer rates in men versus women

The two cancers that are identified in men less commonly than in women are thyroid and gallbladder cancers, according to reliable sources.

Men were 10.80x more likely to be diagnosed with esophageal adenocarcinoma than females, which represented the biggest differential.

Males had a higher risk of developing the following cancers:

Bladder cancer: Trusted Source: 3.3 times more probable

Cardia gastric cancer: 3.49 times more probable

Laryngeal cancer: 3.53 times more probable.

The study’s authors note that a “statistically substantial (nonzero) percentage of the reported male extra for esophageal cancer and malignancies of liver, other biliary systems, bladder, scalp, colon, rectum, and lung” was attributable to behavioral and lifestyle factors.

The impact of the risk factors ranges between 11% for esophageal cancer to 50 percent for lung cancer, but in many cases, this was “just a tiny fraction.”

X chromosome’s “protective advantage:

“An alternative way of looking at it is that women may have a defensive advantage,” said Dr. Jackson. Estrogen may affect immunological signaling pathways, which could be one way that women have an immune edge.

In addition, she continued, “females may have higher expression levels since they have two Xs instead of one, which males do, as the X chromosome carries multiple tumor suppressor genes. We don’t fully grasp these mechanisms at the moment.

The Dana-Farber Cancer Institute’s Dr. Andrew Lane, working with Harvard’s The Broad Institute and MIT, was crucial in identifying the possible contribution of these X chromosomes to the greater cancer incidence in men.

X inactivation is described by Dr. Lane as follows: “For most genes, both male and female cells contain just one active copy of the X chromosome because one X is inactivated in female cells. However, female cells have two copies of these “escape genes” that are active. They are enriched because they are cancer-preventive tumor suppressor genes, it turns out.

He explained that because female cells have two copies of all these protective genes whereas male cells only have one, they are relatively more protected than male cells.

These genes were given the name “EXITS,” which stands for “Escape from X Inhibition Tumor Suppressor.” We continue to search for more EXITS genes that may be unique to as-yet-unstudied cancer subtypes, said Dr. Lane.

In order to determine whether there is a difference in the efficacy of the therapy by sex, it would be advantageous if clinical studies of novel cancer medications were made careful to include enough men and women. One day, he told us, “we might use that data to develop treatments which are more specifically suited to men or women if we continue to identify sex-biased neoplastic cells and varied therapeutic efficacy.

While Dr. Jackson contends that “maintaining a healthy lifestyle and adhering to cancer screening guidelines remain key ways of cancer prevention for both men and women,” it makes sense for males to be extra watchful for indicators of cancer in general. People should talk to their physicians about what they can do to maintain and/or improve their health.