Purpose: The purpose of this study was to examine patient and physician factors influencing the decision to use adjuvant chemotherapy for stage III colon cancer in elderly persons.
Description of study: A cross-sectional mailed population-based survey of patients 65 years of age and older who had undergone surgical resection of stage III colon cancer in Colorado between August 1995 and December 1997 were identified by the statewide cancer registry (n = 276) and their treating physicians (n = 232). A questionnaire about the determinants of colon cancer treatment decisions was mailed to all patients for whom physician permission was granted (n = 119). A similar questionnaire was sent to treating physicians.
Results: Ninety-two physicians (internal medicine 23%; family medicine 12%; surgery 37%; and oncology 24%) and 67 patients (mean age 75.8 years; 55% women) completed surveys. Fifty-four (80.6%) of the patients had received adjuvant chemotherapy. The major determinants of receiving adjuvant chemotherapy were having seen an oncologist (P = .003), being younger (P = .003), and being married (P = .021). After controlling for other potential influences, only having seen an oncologist (odds ratio 8.0; confidence interval 1.5–43.1) remained significantly associated with the receipt of chemotherapy. Physicians were more likely than patients to rank comorbid conditions (39.1% versus 3.0%, respectively; P < .001) and the medical literature (20.7% versus 4.5%, respectively; P = .004) as important factors in making treatment decisions, while patients were more likely than physicians to rank physician opinion (73.1% versus 26.1%, respectively; P = .001), family preference (31.3% versus 9.8%, respectively; P = .001), and family burden (10.4% versus 2.2%, respectively; P = .038).
Clinical implications: In this elderly population, patient age is not recognized by patients or physicians as affecting the decision to use adjuvant chemotherapy. Other biologic and social factors are important, however, and the perspectives of physicians and patients differ regarding their relative importance.