Comorbidities Alone Do Not Explain the Undertreatment of Colorectal Cancer in Older Adults: A French Population‐Based Study

Abstract

To investigate the influence of comorbidities on treatment modalities of colorectal cancer according to the age of patients and French recommendations. Population-based study French Digestive Cancer Registry, Burgundy. Two thousand nine hundred twenty-one incident colorectal cancers diagnosed between 2004 and 2007. The independent influence of comorbidities (recorded according to the Charlson index) on treatment was analyzed using multivariate logistic regressions controlling for age, sex, and their interaction. The association between comorbidities and resection for cure was significant only in patients younger than 75 (P interaction=.008). For Stage III colon cancer, 40.4% of the patients aged 75 and older had adjuvant chemotherapy, versus 90.5% of those younger than 75 (P<.001). The association between comorbidities and adjuvant chemotherapy for Stage III colon cancer was significant only in patients younger than 75 (P interaction=.004). Patients aged 75 and older were less likely to receive chemotherapy, even when they had few or no comorbidities. Overall, 29.3% of patients aged 75 and older with advanced colorectal cancer had palliative chemotherapy, versus 77.1% of those younger than 75 (P<.001). Whatever the age, palliative chemotherapy was less frequent for a Charlson comorbidity index of 2 or greater (P interaction=.16). Radiotherapy was administered in 59.0% of patients aged 75 and older with rectal cancer, versus 85.3% of those younger than 75 (P<.001). Whatever the age, patients with a Charlson score of 2 or greater were less likely to receive radiotherapy for rectal cancer than were patients without comorbidities (P interaction=.86). Further studies are warranted to identify more precisely the reasons for lower treatment rates for colorectal cancer in the older population.