OBJECTIVES: To investigate the influence of comorbidities on treatment modalities of colorectal cancer according to the age of patients and French recommendations.
DESIGN: Population-based study
SETTING: French Digestive Cancer Registry, Burgundy.
PARTICIPANTS: Two thousand nine hundred twenty-one incident colorectal cancers diagnosed between 2004 and 2007.
MEASUREMENTS: 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.
RESULTS: 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).
CONCLUSION: Further studies are warranted to identify more precisely the reasons for lower treatment rates for colorectal cancer in the older population.