Obesity is an independent predictor of poor survival in metastatic breast cancer: retrospective analysis of a patient cohort whose treatment included high-dose chemotherapy and autologous stem cell support

Abstract

The purpose of the study was to identify predictors of long-term survival in metastatic breast cancer (MBC). A cohort of 96 patients, who received high-dose chemotherapy with autologous stem cell support (HD-ASCT) as part of their treatment, was analyzed. Percent long-term survival at 10 years was 24.5% (CI 17.2-34.9%) when metastasis was diagnosed and 14.4% (CI 8.7-23.9%) when MBC was diagnosed. Survival was impacted significantly by body mass index (BMI). Median overall survival from initial diagnosis or from time of metastasis for patients with BMIs ≤30 and >30 (obese) was 7.1 (CI 4.4-8.7) and 3.2 years (2.41-6.75), respectively, or 3.2 or 2.3 years (all P = 0.02). Also, obesity was the only independent patient-related predictor of time to metastasis and of survival. While obesity is linked with poor outcomes in earlier stages of breast cancer, this has not been previously reported for MBC.

Figure 1

Overall survival and progression-free survival for all patients (n = 96) from initial diagnosis (a) and diagnosis of metastasis (b). Survival was estimated by Kaplan-Meier method.

Figure 2

Overall survival (OS) from diagnosis (a) and from time of metastasis (b) and progression-free survival (PFS) from diagnosis (c) and from time to metastasis (d) in patients with a BMI ≤ 30 (n = 73) or >30 (n = 23). Survival was estimated using Kaplan-Meier method.