Abstract P1-07-25: Patterns of multidisciplinary care in the management of nonmetastatic invasive breast cancer in the United States Medicare patient
Authors: Churilla TM , Egleston BL , Murphy CT , Sigurdson ER , Hayes SB , Goldstein LJ , Bleicher RJ 
Published: May 2016

Background: Multidisciplinary care (MDC) in managing localized breast cancer is a resource-intensive treatment strategy that is anecdotally growing in prevalence, but is poorly characterized and thus cannot yet be defined as "standard care." We sought to determine the patterns of MDC care in the United States Medicare patient and assess if survival advantages exist for this paradigm.

Methods: Using the Survival, Epidemiology, and End Results (SEER)-Medicare linked dataset, we evaluated patients with non-metastatic breast cancer from 1992 to 2009. MDC was defined as a preoperative visit after breast cancer diagnosis with a surgeon, medical oncologist and radiation oncologist. Two separate analyses were performed: The first evaluated all MDC patients, and the second characterized the subset of patients who saw all three specialties on the same day. We tested for associations between MDC and clinical/demographic variables using logistic regression and evaluated outcomes using propensity score matching.

Results: A total of 87,984 invasive nonmetastatic breast cancer patients were included. MDC was utilized in 2.8% of patients, while 13% of these saw all three oncologic specialists on the same date. MDC use did not vary significantly according to AJCC stage. Patients receiving MDC overall were significantly more likely to be younger (continuous variable; OR [95% CI] = 0.99 [0.98-0.99]), black race (1.75 [1.50-2.05]), receive lumpectomy (1.15 [1.03-1.28], have fewer nodes examined (0.98 [0.98-0.99], and receive radiation therapy (1.37 [1.25-1.51]. MDC patients receiving care all on the same date were significantly more likely than non-MDC patients to have lobular histology (OR [95% CI] = 1.48 [1.06-2.06]), black race (3.09 [2.19-4.35], receive mastectomy (1.75 [1.34-2.30]) and receive radiation therapy (1.98 [1.52-2.60]). The use of MDC overall and on the same date increased over time (p &lt; 0.001) and varied widely according to geographic region. There was a 20.8 odds increase in the use of same-date MDC in the Midwest compared to the South (p &lt; 0.001). Patients in rural settings were less likely to receive MDC overall: OR [95% CI] = 0.57 [0.48-0.68] and on the same date (0.27 [0.16-0.48]). Survival data suggest improved outcomes for women undergoing MDC (Table 1). There were 117 breast cancer deaths in the MDC overall group but only 15 such events in the smaller MDC same-day subgroup (limiting its power).

Table 1. Propensity score matched outcomes according to MDC.  MDC Overall*  MDC on Same Date   (n = 2,491)  (n = 330)  HR[95% CI]pHR[95% CI]pAdjusted Overall Survival0.940.80-1.090.4000.360.18-0.720.004Adjusted Breast Cancer Specific Mortality0.750.58-0.960.0240.420.15-1.180.102* Includes MDC patients on same and different dates.

Conclusions: The vast majority of Medicare patients having breast cancer did not undergo MDC during the period of study. MDC rates have increased over time, with widely varied MDC utilization across regions. Employing same-day MDC should be considered for patient convenience and may improve outcomes. While not yet widespread, efforts should be made to integrate MDC as standard care across the United States.

Citation Format: Churilla TM, Egleston BL, Murphy CT, Sigurdson ER, Hayes SB, Goldstein LJ, Bleicher RJ. Patterns of multidisciplinary care in the management of nonmetastatic invasive breast cancer in the United States Medicare patient. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-07-25.