RISK-FACTORS FOR MALIGNANT DISEASES - A COHORT STUDY ON A POPULATION OF 22,946 ICELANDERS

The records of a cohort of 11,580 females and 11,366 males participati ng in an Icelandic cardiovascular risk factor study were linked with t he Icelandic Cancer Registry, identifying 1,785 males and 1,490 female s who had been registered with neoplastic diseases from 1968 to 1995, The interval between the time of measurement of the variables and the diagnosis of the malignancy ranged from 4 to 27 years, The variables c onsisted of answers from a questionnaire on smoking and the use of hyp ertensive drugs and anthropometric and biochemical measurements. Cox's regression was applied to analyze the predictive power of the variabl es on the risk of cancer after the first examination at the Heart Prev entive Clinic, Reykjavik, Univariate analyses, adjusted for age, were performed for each variable and each major site, Within each major sit e, multivariate regression analysis was applied for variables that wer e found significantly (10% level in univariate analysis) positive or n egative as risk factors, The results show that smoking is the most imp ortant risk factor, negative only for endometrium, For lung cancer, th e risk is twice as strong for females as it is for males, whereas for pancreas, males have a relative risk ratio of 4.5, compared with 2.4 f or females, Height is a risk factor for all sites for each sex, for br east in females, and for kidney in males, Several anthropometric risk factors were studied, Some of these can describe positive or negative relative risk ratios for cancer, and their use may shed light on cance r pathogenesis, Serum cholesterol is a negative risk factor for breast cancer in females, but triglycerides are a positive risk factor for c ervix cancer in females and for colon or rectum and thyroid cancer in males, Serum glucose is a positive risk factor for prostate cancer and a negative risk factor for lymphomas and leukemias.