Abstract P4-08-26: Validation of different prognostic scores in breast cancer patients with brain metastases of the BMBC registry (GBG-79)

Background The incidence of brain metastases from breast cancer is increasing and treatment is a major challenge. Different scores were developed to estimate the prognosis of patients with brain metastases by objective criteria. Sperduto et al. established the disease-specific breast-graded prognostic assessment (GPA) score in 400 breast cancer patients which includes age, performance status and tumor subtype. It has been described that the Breast- GPA best identifies patients with bad prognosis (Laakmann et al. 2016). Aim of this analysis was to validate the Breast-GPA in a large cohort of breast cancer patients with brain metastases. Materials and methods Data of 613 breast cancer patients from the Brain Metastases in Breast Cancer (BMBC) registry treated in 80 different clinical German institutions between 2000 and 2016 was analyzed. Results 135 patients (22%) had a triple-negative, 199 (32%) a luminal-like und 279 (46%) a HER2-positive primary breast cancer. At diagnosis of brain metastases most patients had a good Karnofsky performance status (100%: 14.4%, 80-90%: 44.7%, 60-70%: 28.9%, 40-50%: 9.0%, 10-30%: 3.1%). Median age of patients was 56 years (22-90 years). Median survival in the overall cohort was 7.1 months (95% CI 6.2-7.8 months). Distribution of GPA scores was: 0-1: 11.9% (n=73), 1,5-2: 22.3% (n=137), 2,5-3: 47.8% (n=293), 3,5-4: 18% (n=110). Median overall survival within the GPA-subgroups varied between 2.4 (CI95% 2.0 - 3.4); 4.8 (3.6 - 6.9); 9.2 (7.2 - 11.3) and 12.3 (8.9 - 18.0) months and, thus, was significantly shorter compared with the times published by Sperduto et al. (3.4; 7.7; 15.1 und 25.3 months). Conclusions The breast-GPA is easy to calculate in clinical routine, allows to assess patients` prognosis objectively and can facilitate making therapeutic decisions. However, absolute survival may differ from the originally published cohort in other settings. Citation Format: Witzel ID, Riecke K, Laakmann E, Weide R, Neunhoeffer T, Park-Simon T-W, Schmidt M, Fasching PA, Hesse T, Polasik A, Mohrmann S, Wurschmidt F, Schem C, Bechtner C, Wurstlein R, Fehm T, Mobus V, Burchardi N, Loibl S, Muller V. Validation of different prognostic scores in breast cancer patients with brain metastases of the BMBC registry (GBG-79) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-08-26.