In a study to determine the non-medical factors that may be associated with the decision to treat nonmetastatic breast cancer, researchers at Columbia University Mailman School of Public Health evaluated the association between oncologist characteristics and the receipt of chemotherapy in elderly women with breast cancer and found that they were more likely to receive chemotherapy if treated by oncologists employed in a private practice.
For elderly women with localized breast cancer (stages 1-3), the researchers report that only 15% of women got treated, and the use of chemotherapy is a judgment call by the oncologist. With regard to younger women with nonmetastatic breast cancer, 70% received adjuvant chemotherapy. The study is published online in Cancer, a journal of the American Cancer Society.
Determinants of receiving cancer treatment have mostly focused on patient-related factors, such as race/ethnicity, geographic location, age, and socioeconomic status. Relatively less research has evaluated the role of the physician and practice setting in the receipt of cancer care. In this study, the researchers investigated the association of oncologist characteristics, such as gender, type of degree, year of graduation and practice setting -- private vs. non-private -- with receipt of adjuvant chemotherapy for elderly patients with early stage breast cancer. Women aged 65 years or older, who were diagnosed with stages I to III breast cancer between 1991 and 2002 were studied, and of 42,544 women identified, 8714 (20%) were treated with adjuvant chemotherapy.
"The most powerful predictor of adjuvant chemotherapy was whether the oncologist was in private practice or not," says Dawn Hershman, MD, assistant professor of Medicine at Columbia College of Physicians & Surgeons and assistant professor of Epidemiology at the Mailman School of Public Health, and first author on the study. "We were surprised to see the strong and consistent relationship between practice setting and chemotherapy use, and even more surprised to see that this association was similar both for patients with a clear indication to high recurrence risk, as well as for those who were likely to have only minimal benefit."
Dr. Hershman suggests the fact that patients at low risk for cancer recurrence, those with estrogen/progesterone receptor positive, stage I/II disease, received treatment regardless of risk factor, could relate to patient volume -- since oncologists in private practice generally have a higher patient volume, or it could be due to patient selection factors -- patients often choose to see physicians for chemotherapy in private settings for convenience, noting that "those with more complicated medical conditions often are treated at university hospitals," says Dr. Hershman. Patient insurance status also may play a role, she observes, since "research has shown that payment mechanisms do, in fact, influence physicians' clinical decision making."