Comorbidities, functional limitations, and geriatric syndromes in relation to treatment and survival patterns among elders with colorectal cancer

To examine patterns of colorectal cancer (CRC) treatment and survival in relation to comorbidities (COM), functional limitations (FL), and geriatric syndromes (GS).

Our study population consisted of Ohio elders diagnosed with incident invasive CRC in the period August 1999 to November 2001 and admitted to home health care (HHC) in the 30 days before or after cancer diagnosis (n = 1009). We used data from the Ohio Cancer Incidence Surveillance System, vital records, and Medicare administrative data, including the HHC Outcome and Assessment Information Set (OASIS), which includes detailed clinical data for HHC patients. Counts of COM, FL, and GS at baseline were retrieved from the OASIS. Multivariable logistic and survival models were developed to examine the association between clinical attributes and outcomes, adjusting for demographic covariates and cancer stage.

Comorbidities were associated with increased likelihood of surgery-only, but not with surgery + chemotherapy. Both FL and GS were associated with lower likelihood to undergo surgery-only or surgery + chemotherapy. Two or more GS was associated with disease-specific mortality (adjusted hazard ratio [AHR]: 2.71; 95% confidence interval [CI]: 1.80-4.07) and overall mortality (AHR: 2.34; 95% CI: 1.74-3.15). Two or more FL was associated with overall mortality (AHR: 1.33; 95% CI: 1.10-1.62), but not with disease-specific mortality. COM was not associated with overall mortality, but was negatively associated with disease-specific mortality at borderline level of significance (AHR: 0.78; 95% CI: 0.61-1.00).

Our findings demonstrate the importance of accounting for FL and GS, in addition to COM, when studying cancer-related outcomes in elders.