ABSTRACT
Background: Brazil is a middle-income country with inequalities in its healthcare system. The disparities between public and private services affect the diagnosis and treatment of patients with breast cancer. The aim of this study is to assess whether disease-free survival (DFS) and overall survival (OS) are different in public and private specialized centers. Patient and methods: A retrospective cohort study with 1,545 breast cancer patients diagnosed from 2003 to 2011 at Barretos Cancer Hospital-BCH (public group, N = 1,408) and InORP Oncoclinicas (private group, N = 137) was conducted. A 1:1 propensity score matching (PSM) analysis was used to adjust the differences between the groups' characteristics (n = 137 in each group). Results: The median age at diagnosis was 54.4 years. Estimated DFS rates at 1, 5, and 10 years were 96.0%, 71.8%, and 59.6%, respectively, at BCH and 97.8%, 86.9%, and 78%, respectively, at InORP (HR: 2.09; 95% confidence interval [CI], 1.41-3.10; p < 0.0001). Estimated OS rates at 1, 5, and 10 years were 98.1%, 78.5%, and 65.4%, respectively, at BCH and 99.3%, 94.5%, and 91.9%, respectively, at InORP (HR: 3.84; 95% CI, 2.16-6.82; p < 0.0001). After adjustment by PSM, DFS and OS results in 1, 3, and 5 years remained worse in the public service compared to the private service. Conclusion: Patients treated in a public center have worse DFS and OS after a follow-up period of more than 5 years. These results were corroborated after carrying out the PSM.
ABSTRACT
Brain metastases remain an unmet clinical need in breast oncology, being frequently found in HER2-overexpressing and triple-negative carcinomas. These tumors were reported to be highly cancer stem-like cell-enriched, suggesting that brain metastases probably arise by the seeding of cancer cells with stem features. Accordingly, we found that brain-tropic breast cancer cells show increased stem cell activity and tumorigenic capacity in the chick embryo choriallantoic membrane when compared to the parental cell line. These observations were supported by a significant increase in their stem cell frequency and by the enrichment for the breast cancer stem cell (BCSC) phenotype CD44+CD24-/low. Based on this data, the expression of BCSC markers (CD44, CD49f, P-cadherin, EpCAM, and ALDH1) was determined and found to be significantly enriched in breast cancer brain metastases when compared to primary tumors. Therefore, a brain (BR)-BCSC signature was defined (3-5 BCSC markers), which showed to be associated with decreased brain metastases-free and overall survival. Interestingly, this signature significantly predicted a worse prognosis in lymph node-positive patients, acting as an independent prognostic factor. Thus, an enrichment of a BCSC signature was found in brain metastases, which can be used as a new prognostic factor in clinically challenging breast cancer patients.