The role of the surgeon in whether patients with lymph node-positive colon cancer see a medical oncologist

BACKGROUND. Chemotherapy improves survival for patients with stage III colon cancer, but some older patients with lymph node-positive colon cancer do not see a medical oncologist and, thus, do not receive adjuvant chemotherapy. METHODS. To evaluate the role of the surgeon in determining referrals to medical oncology among patients with stage III colon cancer, the authors conducted a retrospective cohort study of 6158 patients aged ≥66 years who were diagnosed with stage III colon cancer from 1992 through 1999 by using the Surveillance, Epidemiology, and End Results-Medicare linked database. Multilevel analysis was used to simultaneously model variations in patients' seeing a medical oncologist at the patient and surgeon levels. RESULTS. Twenty-one percent of the total variance in seeing a medical oncologist was attributable to the surgeon after adjusting for available patient, tumor, and surgeon characteristics. The individual surgeon characteristics that significantly predicted whether the patient saw a medical oncologist were year since graduation (≤10 years vs >20 years; hazard ratio [HR], 1.60; 95% confidence interval [95% CI], 1.19-2.16), practicing in a teaching hospital (yes vs. no: HR; 1.30; 95% CI, 1.07-1.58), and volume of patients with colon cancer (<30 patients vs ≥121 patients; HR, 0.66; 95% CI, 0.46-0.94). Surgeon sex, race, board certification, and type of practice were not independent predictors of medical oncology referral. CONCLUSIONS. Surgeons accounted for approximately 20% of the variation in patients seeing a medical oncologist. Interventions at the level of the surgeon may be appropriate to improve the care of patients with colon cancer.