Is cancer incidence decreased in the frail elderly? Evidence from a prospective cohort study

Objectives: Lower rates of cancer in the oldest old and in nursing home populations may reflect the increasing prevalence of frailty and a diminished capacity to sustain cancer cell growth and proliferation. This study aimed to determine cancer incidence in the frail relative to non-frail community resident older adults.

Materials and methods: Data from 3969 participants free of diagnosed cancer at the sixth follow-up from three sites of the Established Populations for Epidemiologic Studies of the Elderly (EPESE), a population-based cohort study. Frailty status was determined from physical performance testing and self reported dependency in activities of daily living. Cancer incidence over the four subsequent years was identified through linkage with Medicare claims data. Logistic regression was used to estimate the odds of cancer incidence with respect to frailty status in multiple models with progressive adjustment for covariates.

Results: Of the 3969 participants, 1340 (33.8%) were identified as frail. Cancer incidence at 4years was lower in frail participants overall (OR 0.64; 95% CI 0.46-0.89) and frail men in particular (OR 0.54; 95% CI 0.33-0.87). Incidence was lower in women (3.7%) than in men (8.8%), but was not lower in frail women compared with non-frail women (OR 0.77; 95% CI 0.48-1.23).

Conclusion: Frailty status was associated with decreased cancer incidence, particularly in men, and suggests that mechanisms related to the pathogenesis of frailty may also play a role in inhibiting tumorigenesis. Why this would be more apparent in men than women remains to be clarified.