The association of blood pressure with cancer incidence in a prospective study.

A cohort of 8,006 Japanese-American men living in Hawaii was examined from 1965 to 1968 and followed for about 20 years. The study identified 1,155 incident cases of histologically confirmed cancer and 648 deaths due to cancer. There was no association between systolic or diastolic blood pressure and total cancer incidence or deaths due to cancer. The relative risk was 1.03 for cancer incidence and 1.00 for cancer mortality for subjects with a systolic pressure of 160 mmHg or greater. Adjustment was made for age, smoking, alcohol, and measures related to obesity. When cancers of specified sites were studied, blood pressure was positively associated with the incidence of kidney cancer (17 cases). After adjustment for the significant effect of taking antihypertensive medication, the effect of blood pressure became nonsignificant. Among seven other cancer sites, there were no statistically significant associations with blood pressure after adjustment for confounding factors.