Abstract P4-07-42: Intervention to Distant Metastatic Lesions in Patients with Breast Cancer

Abstract INTRODUCTION Approximately one-fourth of patients presenting with early-stage breast cancer develop distant metastatic disease, a prominent cause of mortality. The role of metastasis-directed intervention is still uncertain in this cohort. The aim of this study is to evaluate whether intervention to metastatic lesions impacts overall survival (OS) and post-distant recurrence survival (PDRS), defined as survival after first occurrence of metastatic disease. METHODS Our prospectively maintained international multi-center database of patients diagnosed with distant recurrence was retrospectively reviewed. Patients initially presenting with stage I-III breast cancer and diagnosed with metastatic disease to the bone, liver or lung from 2014-2020 were divided into cohorts receiving intervention to their metastases (IM, n=180) versus no interventions to their metastases (NI, n=120). The characteristics of the patients were compared with X2 test. OS curves were calculated by Kaplan-Meier method and multivariable analysis by Cox regression. Statistical significance was set at p< 0.05. RESULTS No significant differences in OS and PDRS were noted between the two groups when comparing age at diagnosis, menopausal status, tumor histopathology, pathological stage, axillary lymph node involvement, and hormone receptor and HER2 status. However, median OS and PDRS were significantly longer for patients who received IM compared to those who did not. The hazard of death was 59% lower with IM than with NI for both OS (HR 0.59: 95% CI 0.42 – 0.83; p=0.002) and for PDRS (HR 0.59: 95% CI 0.42 – 0.84). On multivariable analysis, OS was improved among patients with IM, and among those with lung metastases, compared to liver and bone metastases. CONCLUSIONS Metastatic site intervention had both an OS and PDRS benefit in this cohort. In order to explore the potential for interventions to their metastases, patients who develop limited metastatic disease following initial breast surgery should be discussed at a multidisciplinary tumor board. Post-Distant Recurrence Survival in Patients with Breast Cancer Receiving Intervention to Metastatic Lesions (IM) Versus No Intervention (NI) Citation Format: Hira Abidi, Serdar Ozbas, Beyza Ozcinar, Lutfi Dogan, Arda Isik, Emilia Diego, Priscilla F. McAuliffe, Ronald Johnson, Jennifer Steiman, Efe Sezgin, Atilla Soran. Intervention to Distant Metastatic Lesions in Patients with Breast Cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-07-42.