Impact of referral patterns on the use of chemotherapy for lung cancer

To determine the extent to which unexplained variation in the use of chemotherapy for advanced lung cancer is due to access to oncologists' services as opposed to treatment decisions made after seeing an oncologist.

We performed a retrospective cohort study of 12,015 patients over age 65 diagnosed with metastatic lung cancer between 1991 and 1996 while living in one of 11 regions monitored by a Survival, Epidemiology, and End Results (SEER) tumor registry. Assessment by an oncologist and subsequent treatment with chemotherapy were determined by examining linked Medicare claims.

Of patients who did not receive chemotherapy, 36% were never assessed by a physician who provides chemotherapy. Patients living in certain areas, those diagnosed in more recent years, and those who received care in a teaching hospital were all more likely to see a cancer specialist. These factors were unrelated to subsequent treatment decisions, however. Conversely, age and comorbidity did not have a significant effect on whether a patient was seen by an oncologist, but they were associated with the likelihood of subsequently receiving chemotherapy. Black race, probably acting as a proxy for lower socioeconomic status, was associated with both a diminished likelihood of seeing a cancer specialist and subsequently receiving chemotherapy.

Nonmedical factors are important determinants of whether a lung cancer patient is seen by a physician who provides chemotherapy. After seeing such a physician, treatment decisions seem to be mostly explained by appropriate medical factors. Racial and socioeconomic disparities still exist at both steps, however. As therapeutic options expand, referring physicians must ensure that biases and barriers to care do not deprive patients of the opportunity to consider all of their treatment options.