Nonclinical factors associated with the treatment of older women with newly diagnosed low-grade ductal carcinoma in situ.

backgroundDuctal carcinoma in situ (DCIS) is the most common form of noninvasive breast cancer and is associated with an excellent prognosis. As a result, there is concern about overdiagnosis and overtreatment of DCIS because most patients with DCIS are treated as though they have invasive breast cancer and undergo either breast-conserving surgery (BCS)-most commonly followed by radiation therapy (RT)-or mastectomy. Little research to date has focused on nonclinical factors influencing treatments for DCIS.

methodsPopulation-based data were analyzed from five state cancer registries (California, Florida, New Jersey, New York, and Texas) on women aged 65 years and older newly diagnosed with DCIS during the years 2003 to 2014 using a retrospective cohort design and multinominal logistic modeling. The registry records with Medicare enrollment data and fee-for-service claims to obtain treatments (BCS alone, BCS with RT, or mastectomy) were merged. Surgeon practice structure was identified through physician surveys and internet searches.

resultsPatients of surgeons employed by cancer centers or health systems were less likely to receive BCS with RT or mastectomy than patients of surgeons in single specialty or multispecialty practices. There also was substantial geographic variation in treatments, with patients in New York, New Jersey, and California being less likely to receive BCS with RT or mastectomy than patients in Texas or Florida.

conclusionsThese findings suggest nonclinical factors including the culture of the practice and/or financial incentives are significantly associated with the types of treatment received for DCIS. Increasing awareness and targeted efforts to educate physicians about DCIS management among older women with low-grade DCIS could reduce patient harm and yield substantial cost savings.