Background: Host factors expressed by individual past medical history of hypertension, stroke, and myocardial infarction may have a relationship with colorectal cancer.
Methods: As part of the Japan Collaborative Cohort Study (JACC Study) for the Evaluation of Cancer Risk sponsored by the Ministry of Education, Science, Sports and Culture of Japan (Monbusho), we conducted a follow-up study of 110,792 Japanese inhabitants aged 40-79 years to reveal the relationship of past medical history of hypertension, stroke, and myocardial infarction at the baseline in 1988-1990 with colorectal cancer death for about 10 years up to the end of 1999.
Results: Past medical history of hypertension associated with an increased risk of female rectal cancer when analyzing all cancer cases with adjustment for age, body mass index, and exercise (hazard ratio [HR]=1.97, 95% confidence interval [CI]; 1.13-3.43). Past medical history of myocardial infarction was also an increased risk for female rectal cancer (HR=3.05, 95% CI; 1.28-7.28). Females who had a medical history of stroke had increased risk of rectal cancer without statistical significance.
Conclusion: There was a positive association of past medical history of hypertension and myocardial infarction and an increased risk of rectal cancer in women.