Men tend to have a higher risk of cancer than women, and factors such as smoking, alcohol use and diet do not appear to explain this disparity, according to a study published in Cancer.
The researchers compared gender differences for 21 types of cancer and found that men had a higher incidence of most of the cancers studied.
For the most part, this higher susceptibility could not be explained by carcinogenic exposures. The researchers theorized that it can be explained by interrelated biological differences between the sexes.
This study was designed to evaluate behaviors, anthropometrics, lifestyles, and medical history to try to explain the higher risk of cancer in men. The researchers analyzed data from the National Institutes of Health-AARP Diet and Health Study (1995-2011).
The cohort included 171,274 male and 122,826 female participants. There was a total of 26,693 incident cancers — 17,951 in men and 8742 in women.
Men had a lower age-adjusted incidence of thyroid cancer (incidence rate ratio [IRR], 0.59; 95% CI, 0.49-0.70) and gallbladder cancer (IRR, 0.65; 95 % CI, 0.44-0.94) from women. The incidence of anal cancer was similar between groups (IRR, 0.97; 95% CI, 0.70-1.34).
For all other types of cancer studied, men had a higher incidence than women. The largest differences were seen for esophageal adenocarcinoma (IRR, 12.19; 95% CI, 8.32-17.86), gastric cardia cancer (IRR, 4.93; 95% CI, 3.59-6.77), and laryngeal cancer ( IRR, 3.99%; , 3.07-5.17).
These 3 cancers had the highest male-to-female hazard ratios (HRs) when the researchers adjusted for demographic, lifestyle and dietary factors. The HR was 10.80 for esophageal adenocarcinoma (95% CI, 7.33-15.90), 3.53 for laryngeal cancer (95% CI, 2.46-5.06), and 3.49 for gastric cardia cancer (95% CI, 2.26 -5.37).
Men still had a lower risk of thyroid cancer (HR, 0.55; 95% CI, 0.46-0.66) and gallbladder cancer (HR, 0.33; 95% CI, 0.18-0.58) in the adjusted analysis as well .
The researchers noted that the risk factors explained a proportion of the male excess for esophageal adenocarcinoma and cancers of the liver, other biliary tract, bladder, skin, colon, rectum and lung.
“However, only a modest proportion of the male excess was explained by risk factors (ranging from 50% for lung cancer to 11% for esophageal adenocarcinoma)”, wrote the researchers.
“Collectively, our results point to the potential role of sex-related biological mechanisms, rather than differences in carcinogenic exposures, as the main determinants of male-female differences in cancer risk in most -larger shared anatomical sites It is hypothesized that the higher susceptibility of cancer at shared anatomical sites in men results from several interrelated biological differences between the sexes, including physiological, immunological, genetic, epigenetic and genological mechanisms.
The researchers suggested that a global evaluation of these mechanisms across cancer sites should be done to help characterize whether they contribute to the greater burden of cancer in men.
Disclosure: One study author has declared an affiliation with Merck. Please see the original reference for details.
Jackson SS, Marks MA, Katki HA, et al. Gender disparities in the incidence of 21 types of cancer: Quantifying the contribution of risk factors. Cancer. Published online 8 August 2022. doi:10.1002/cncr.34390
