Collaboration between surgeons and medical oncologists and outcomes for patients with stage III colon cancer

Purpose: Collaboration between specialists is essential for achieving high-value care in patients with complex cancer needs. We explore how collaboration between oncologists and surgeons affects mortality and cost for patients requiring multispecialty cancer care. Patients and Methods: This was a retrospective cohort study of patients with stage III colon cancer from SEER-Medicare diagnosed between 2000 and 2009. Patients were assigned to a primary treating surgeon and oncologist. Collaboration between surgeon and oncologist was measured as the number ofpatients shared between them; this has been shown to reflect advice seeking and referral relationships between physicians. Outcomes included hazards for all-cause mortality, subhazards for colon cancer-specific mortality, and cost of care at 12 months. Results: A total of 9,329 patients received care from 3,623 different surgeons and 2,319 medical oncologists, representing 6,827 unique surgeon-medical oncologist pairs. As the number of patients shared between specialists increased from to one to five (25th to 75th percentile), patients experienced an approximately 20% improved survival benefit from all-cause and colon cancer-specific mortalities. Specifically, for each additional patient shared between oncologist and surgeon, all-cause mortality improved by 5% (hazard ratio, 0.95; 95%CI, 0.92 to 0.97), and colon cancer-specific mortality improved by 5% (subhazard ratio, 0.95; 95% CI, 0.91 to 0.97). There was no association with cost. Conclusion: Specialist collaboration is associated with lower mortality without increased cost among patients with stage III colon cancer. Facilitating formal and informal collaboration between specialists may be an important strategy for improving the care of patients with complex cancers.