Frailty modulates the predictive value of performance status in older adults living with cancer

Cancer prognosis in older adults is complicated by age-related vulnerabilities such as frailty, which may impact the performance of traditional prognostic tools, which may not accurately reflect risk in this population.

This study aimed to assess whether frailty modifies the association between a modified performance status (PS) -constructed from days spent in bed, physical activity, and disability-and mortality risk in older adults with cancer.

We conducted a secondary analysis of the Mexican Health and Aging Study (MHAS), including individuals ≥50 years with incident cancer and active treatment, with follow-up through 2021. A frailty index (FI) was calculated using a 33-item deficit accumulation model. Modified PS was constructed using data on days in bed, functional limitations, and physical activity. Participants were stratified into low (<0.25) and high (≥0.25) frailty levels. Cox regression and Kaplan-Meier curves were used to assess associations with all-cause mortality.

Among 318 participants (mean age 68.0 years; 62.6% women), frailty and performance status were both associated with mortality. In individuals with low frailty, modified PS categories 2 and 4 were significantly associated with higher mortality (HR 5.46 [95% CI: 1.24-24.04], and HR 8.01 [1.50-42.66], respectively). Among those with high frailty, only age remained a significant predictor of mortality (HR 1.04 [1.00-1.07]).

Frailty significantly modifies the prognostic value of performance status. In frail older adults with cancer, the predictive utility of performance status tools is reduced.

Incorporating frailty assessment may enhance risk stratification and clinical decision-making in older adults with cancer.