Personalized frailty risk assessment in long-term survivors of colorectal cancer.

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Background: Frailty, a pathologic form of aging, is associated with reduced quality of life and increased risk of death. Its incidence increases with age. Frailty is a concern for cancer survivors, especially since this population is surviving longer and increasing in size. There is a need to predict which patients are at risk of frailty to tailor preventative measures, particularly in early-stage colon and rectal cancer survivors, the largest group in gastrointestinal cancer survivors. Methods: This was a retrospective cohort study of individuals aged 66 and older in the SEER-Medicare linked database, diagnosed with stage I-III colon or rectal cancer between 2003-2012. Patients included in the study received definitive surgical treatment and survived for at least 5 years after diagnosis. Frailty was assessed using administrative claims codes with the Kim frailty index. Patients already frail at year 5 were excluded from the analysis. An increase in frailty score, indicating the onset of frailty or worsening to moderate or severe frailty, occurring within 5-10 years following cancer diagnosis was the primary outcome. Predictors of frailty were identified using restricted mean survival time (RMST) regression, with results less than 1 indicating a shorter time to frailty, and significant factors were used to develop a clinical prediction model and stratify patients into risk tertiles. Results: At 10 years or end of available follow-up, 58% of the patients had developed new onset or worsening frailty. There were no significant differences in RMST by patient race, sex, cancer stage and grade. Receipt of systemic therapy 4-5 years after diagnosis, having an ostomy present in years 4-5, advancing age, comorbidities, and living in an area with a greater proportion of residents below the federal poverty line were all associated with shorter time to frailty; the largest effects were seen with advancing age and comorbidities (Table). Our clinical prediction model incorporated age>85 and having multiple comorbidities for both cohorts and ostomy in years 4-5 for the colon cohort. Conclusions: Our population level analysis provided a clinical prediction model for frailty 5-10 years after cancer diagnosis in colon and rectal cancer survivors and may help inform long-term survivorship management.

RMST for selected variables.