Sex differences in subtypes, risk profiles, and mortality for cancer among 19,702 Japanese patients with ischemic stroke: A cohort from BioBank Japan

BACKGROUND: Limited data exists on sex-specific differences in cancer subtypes, risk profiles, and mortality among patients with ischemic stroke. METHODS: This study analyzed 19,702 ischemic stroke patients (n = 12,241 men; n = 7,261 women) registered in the BioBank Japan database. We compared adjusted odds ratios (aOR) and 95 % confidence intervals (CI) for the prevalence of cancer across 14 common anatomical sites and sex-specific cancers between men and women. A multivariate logistic regression model was used to estimate aORs and 95 %CIs for traditional stroke risk factors associated with a cancer history by sex. Cox proportional hazards regression was used to estimate adjusted hazard ratios (aHR) and 95 %CIs for mortality based on cancer history by sex. RESULTS: Among the 19,702 individuals, 1,656 (8.4 %) had a history of cancer. Men showed significantly higher incidences of gastric (aOR 1.74[1.26-2.41]), bladder (aOR 3.49[1.73-3.03]), kidney (aOR 4.74[1.84-12.25]), and pharyngeal/laryngeal (aOR 6.65[2.17-20.39]) cancers compared to women. Conversely, sex-specific cancers (aOR 0.66[0.52-0.84]) were significantly less common in men than in women. In men, older age (aOR 1.80[1.67-1.94]), chronic kidney disease (aOR 1.73[1.23-2.44]), atrial fibrillation (aOR 1.38[1.07-1.77]), smoking (aOR 1.27[1.09-1.47]), and prior stroke (aOR 1.16[1.02-1.32]) were independently associated with a history of cancer. In women, older age (aOR 1.15[1.05-1.25]) was the only independent factor associated with a cancer history. During a median follow-up of 10 years, a history of cancer increased all-cause mortality risk in both men (aHR 1.27[1.16-1.39]) and women (aHR 1.32[1.14-1.48]). CONCLUSION: Sex-specific differences in cancer subtypes and risk profiles were present among patients with ischemic stroke.