Abstract P6-09-21: Prognostic impact of metastatic pattern in stage IV breast cancer at initial diagnosis

Abstract

Background: Stage IV breast cancer at initial diagnosis (BCID) can be recognized in approximately 5% of all breast neoplasms. Clinical outcomes of these patients (pts) are highly variable and depend on tumor biology and pt characteristics. The prognostic influence of metastatic pattern (MP) at initial presentation and factors associated with specific organ involvement have been understudied. The primary aim of this study was to analyze the influence of MP compared with other biologic and clinical factors in the survival of pts with stage IV BCID. The secondary aim was to evaluate factors associated with specific sites of metastatic spread. Methods: We evaluated women with microscopically confirmed stage IV BCID with known metastatic sites, reported to the Surveillance, Epidemiology and End Results (SEER) 18 registries program from 2010 to 2013. Pts with other primary tumor either before or after breast cancer were excluded. MP was categorized as bone only, visceral (lung, liver or brain), bone and visceral and other. Pt characteristics were compared between MP. Univariate and multivariate analyses determined the effects of each variable on overall survival (OS). Logistic regression examined factors associated with specific sites of metastases. Results: We included 9143 pts. Median age was 61 years (range 19-102). Median OS for the entire cohort was 28 months (95% CI 27-29 months). At diagnosis, bone only metastases represented 37.5% of pts, visceral 21.9%, bone and visceral 28.8% and other 11.9%. Median OS by MP was: bone only 38 months, visceral 21 months, bone and visceral 19 months and other 33 months (p Conclusions: To our knowledge, this is the largest study of MP in stage IV BCID. There were substantial differences in prognosis according to MP, bone only was the most common MP and had the best OS, whereas bone and visceral MP had the worst prognosis. We observed significant differences in pt characteristics according to MP. Independent predictors of OS included age at diagnosis, race, marital status, tumor grade, tumor subtype and MP. There was a clear influence of tumor subtype among other factors on specific sites of metastases. Our study identified several prognostic factors that could guide therapy selection in treatment naive pts.Background: Stage IV breast cancer at initial diagnosis (BCID) can be recognized in approximately 5% of all breast neoplasms. Clinical outcomes of these patients (pts) are highly variable and depend on tumor biology and pt characteristics. The prognostic influence of metastatic pattern (MP) at initial presentation and factors associated with specific organ involvement have been understudied. The primary aim of this study was to analyze the influence of MP compared with other biologic and clinical factors in the survival of pts with stage IV BCID. The secondary aim was to evaluate factors associated with specific sites of metastatic spread. Methods: We evaluated women with microscopically confirmed stage IV BCID with known metastatic sites, reported to the Surveillance, Epidemiology and End Results (SEER) 18 registries program from 2010 to 2013. Pts with other primary tumor either before or after breast cancer were excluded. MP was categorized as bone only, visceral (lung, liver or brain), bone and visceral and other. Pt characteristics were compared between MP. Univariate and multivariate analyses determined the effects of each variable on overall survival (OS). Logistic regression examined factors associated with specific sites of metastases. Results: We included 9143 pts. Median age was 61 years (range 19-102). Median OS for the entire cohort was 28 months (95% CI 27-29 months). At diagnosis, bone only metastases represented 37.5% of pts, visceral 21.9%, bone and visceral 28.8% and other 11.9%. Median OS by MP was: bone only 38 months, visceral 21 months, bone and visceral 19 months and other 33 months (p Conclusions: To our knowledge, this is the largest study of MP in stage IV BCID. There were substantial differences in prognosis according to MP, bone only was the most common MP and had the best OS, whereas bone and visceral MP had the worst prognosis. We observed significant differences in pt characteristics according to MP. Independent predictors of OS included age at diagnosis, race, marital status, tumor grade, tumor subtype and MP. There was a clear influence of tumor subtype among other factors on specific sites of metastases. Our study identified several prognostic factors that could guide therapy selection in treatment naive pts. Citation Format: Leone BA, Vallejo CT, Romero AO, Machiavelli MR, Perez JE, Leone J, Leone JP. Prognostic impact of metastatic pattern in stage IV breast cancer at initial diagnosis [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-09-21.