Abstract P1-16-01: Morbidity of primary local therapy for locally advanced metastatic breast cancer: An analysis of the surveillance, epidemiology and end results (SEER)-medicare registry
Authors: Fairweather M , Jiang W , Keating NL , Freedman RA , Nakhlis F 
Published: May 2016

Introduction: About 5-10% of newly diagnosed breast cancers present with de novo metastatic disease. Clinicians are increasingly faced with the dilemma of how to manage a primary tumor that may produce physical and emotional discomfort in the setting of stable distant disease. Lack of outcome data for primary local therapy (PLT) in locally advanced metastatic breast cancer (LAMBC) makes patient counseling difficult. We conducted a population-based analysis of morbidity of PLT among older women with LAMBC. Methods: Patients with de novo LAMBC (T4M1) diagnosed between 2005 and 2009 were identified in the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. Rates of treatment-related complications seen within 1 year of diagnosis and overall 1-year survival were analyzed. Complications were identified using ICD 9 codes (table 1). Results: Among 5,111 patients with LAMBC most did not have PLT (N=3699, 72%). PLT included surgery (N=656, 13%), radiation (N=542, 11%), and both surgery and radiation (N=214, 4%). The most common surgeries were modified radical mastectomy (N=558, 53%) and total mastectomy (N=207, 20%). Complication rates differed significantly by type of PLT, with highest rates seen in patients who had surgery plus radiation.

Patient characteristics and outcomes, by PLT Surgery (N=761)Surgery and Radiation (N=284)Radiation (N=472)Neither (N=3594)P valueER Positive440 (67%)151 (71%)373 (69%)2348 (64%)&lt;0.0001ER Negative177 (27%)51 (24%)108 (20%)740 (20%) Grade I47 (7%)17 (8%)41 (8%)276 (8%)&lt;0.0001Grade II234 (36%)75 (35%)163 (30%)993 (27%) Grade III315 (48%)99 (46%)178 (33%)1150 (31%) Charlson comorbidity index, p&lt;0.00010465 (71%)127 (59%)336 (62%)2649 (72%) 193 (14%)53 (25%)123 (23%)495 (13%) 248 (7%)23 (11%)53 (10%)269 (7%) ≥350 (8%)11 (5%)30 (6%)286 (8%) OutcomesBleeding4 (0.5%)2 (0.7%)7 (1.5%)24 (0.7%)0.04Cellulitis32 (4.2%)17 (6%)12 (2.5%)66 (1.8%)&lt;0.0001Brachial plexopathy11 (1.5%)12 (4.2%)17 (3.6%)30 (0.8%)&lt;0.0001Wound dehiscence7 (0.9%)9 (3.2%)2 (0.4%)8 (0.2%)&lt;0.0001Cancer-related pain30 (4%)38 (13%)60 (13%)131 (4%)&lt;0.0001Lymphedema18 (2.4%)25 (8.8%)8 (1.7%)17 (0.5%)&lt;0.0001All complications122 (16%)99 (34.9%)103 (21.8%)349 (9.7%)&lt;0.00011-year survival74%87%69%51%&lt;0.0001

Patients who did not have PLT had a complication rate of 9.8%. Cancer-related pain was the most frequent complication, with patients who had surgery and radiation and radiation alone having higher rates of it (13%) vs. surgery only and no intervention (4% each, p&lt;0.0001). One-year survival was higher in patients who had surgery and radiation (87%), surgery only (74%), and radiation only (69%) vs. no intervention (51%) (p&lt;0.0001). Conclusions: Few LAMBC patients who did not undergo PLT had local complications, suggesting a low burden of discomfort from untreated local disease. Women who had both surgery and radiation were found to have the highest complication rates and the highest 1-year overall survival. These results should be interpreted with caution, as patients having PLT are likely to be a highly selected group. Prospective data to inform these patients' management are required.

Citation Format: Fairweather M, Jiang W, Keating NL, Freedman RA, Nakhlis F. Morbidity of primary local therapy for locally advanced metastatic breast cancer: An analysis of the surveillance, epidemiology and end results (SEER)-medicare registry. [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 P1-16-01.