Self-rated health and cancer risk - a prospective cohort study among Danish women

BACKGROUND: Self-rated health (SRH) has been shown to be a strong predictor of mortality from a number of major chronic diseases, however, the association with cancer remains unclear. The aim of this study was to investigate a possible association between change in SRH and cancer incidence.

MATERIALS AND METHODS: SRH and information on lifestyle and other risk factors were obtained for 13-636 women in the Danish Nurse Cohort. Cancers that developed during 12 years of follow-up were identified in the National Patient Registry. An association between SRH and cancer was examined in a Cox proportional hazards model with adjustment for age, smoking, alcohol, marital status, physical activity, body mass index and estrogen replacement therapy.

RESULTS: No significant association was found between SRH and overall cancer incidence in the age-adjusted Cox proportional hazards model (1.04; 95% CI 0.93-1.16), even after adjustment for potential confounding factors (HR 1.08; 95% CI 0.96-1.21). Likewise, there was no significant association between SRH and breast cancer (HR 1.09; 95% CI 0.89-1.33), lung cancer (HR 1.03; 95% CI 0.71-1.49) or colon cancer (HR 1.08; 95% CI 0.75-1.54).

CONCLUSION: SRH is not significantly associated with the incidence of all cancers or breast, lung or colon cancer among Danish female nurses. Women who reported a decrease in SRH between 1993 and 1999 had the same risk for cancer as those who reported unchanged or improved SRH.