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 value 
ER Positive 440 (67%) 151 (71%) 373 (69%) 2348 (64%) <0.0001 
ER Negative 177 (27%) 51 (24%) 108 (20%) 740 (20%)   
Grade I 47 (7%) 17 (8%) 41 (8%) 276 (8%) <0.0001 
Grade II 234 (36%) 75 (35%) 163 (30%) 993 (27%)   
Grade III 315 (48%) 99 (46%) 178 (33%) 1150 (31%)   
Charlson comorbidity index, p<0.0001 
465 (71%) 127 (59%) 336 (62%) 2649 (72%)   
93 (14%) 53 (25%) 123 (23%) 495 (13%)   
48 (7%) 23 (11%) 53 (10%) 269 (7%)   
≥3 50 (8%) 11 (5%) 30 (6%) 286 (8%)   
Outcomes 
Bleeding 4 (0.5%) 2 (0.7%) 7 (1.5%) 24 (0.7%) 0.04 
Cellulitis 32 (4.2%) 17 (6%) 12 (2.5%) 66 (1.8%) <0.0001 
Brachial plexopathy 11 (1.5%) 12 (4.2%) 17 (3.6%) 30 (0.8%) <0.0001 
Wound dehiscence 7 (0.9%) 9 (3.2%) 2 (0.4%) 8 (0.2%) <0.0001 
Cancer-related pain 30 (4%) 38 (13%) 60 (13%) 131 (4%) <0.0001 
Lymphedema 18 (2.4%) 25 (8.8%) 8 (1.7%) 17 (0.5%) <0.0001 
All complications 122 (16%) 99 (34.9%) 103 (21.8%) 349 (9.7%) <0.0001 
1-year survival 74% 87% 69% 51% <0.0001 
  Surgery (N=761) Surgery and Radiation (N=284)Radiation (N=472) Neither (N=3594) P value 
ER Positive 440 (67%) 151 (71%) 373 (69%) 2348 (64%) <0.0001 
ER Negative 177 (27%) 51 (24%) 108 (20%) 740 (20%)   
Grade I 47 (7%) 17 (8%) 41 (8%) 276 (8%) <0.0001 
Grade II 234 (36%) 75 (35%) 163 (30%) 993 (27%)   
Grade III 315 (48%) 99 (46%) 178 (33%) 1150 (31%)   
Charlson comorbidity index, p<0.0001 
465 (71%) 127 (59%) 336 (62%) 2649 (72%)   
93 (14%) 53 (25%) 123 (23%) 495 (13%)   
48 (7%) 23 (11%) 53 (10%) 269 (7%)   
≥3 50 (8%) 11 (5%) 30 (6%) 286 (8%)   
Outcomes 
Bleeding 4 (0.5%) 2 (0.7%) 7 (1.5%) 24 (0.7%) 0.04 
Cellulitis 32 (4.2%) 17 (6%) 12 (2.5%) 66 (1.8%) <0.0001 
Brachial plexopathy 11 (1.5%) 12 (4.2%) 17 (3.6%) 30 (0.8%) <0.0001 
Wound dehiscence 7 (0.9%) 9 (3.2%) 2 (0.4%) 8 (0.2%) <0.0001 
Cancer-related pain 30 (4%) 38 (13%) 60 (13%) 131 (4%) <0.0001 
Lymphedema 18 (2.4%) 25 (8.8%) 8 (1.7%) 17 (0.5%) <0.0001 
All complications 122 (16%) 99 (34.9%) 103 (21.8%) 349 (9.7%) <0.0001 
1-year survival 74% 87% 69% 51% <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.