Aims: Current international consensus confirms that certain histopathologic factors such as tumor morphology, histologic grade and presence of lymphovascular invasion are correlated with prognosis. This study evaluated the correlation between histopathologic profile and time to disease progression over 1.5 years among Filipino Stage I-III early breast cancer patients given chemotherapy.
Methods: This retrospective cohort study included all eligible Stage I-III breast cancer patients enrolled in the Department of Health (DOH) Breast Cancer Medicine Access Program at the medical oncology clinics of two tertiary hospitals in Manila from April 2011 to December 2012. Histopathologic factors of interest such as histologic type/grade, lymphovascular invasion, and axillary lymph node involvement were gathered from patient records. The patients were grouped according to the St. Gallen definition of risk categories for patients with breast cancer. Kaplan-Meier survival analysis determined the average time to disease progression as well as progression-free survival over 1.5-years follow-up, while multivariate logistic regression determined independent clinical and histopathologic factors contributing to disease progression.
Results: A total of 326 patients were included in the study. Eighteen percent (18%) showed progression, with a median time-to-progression of 14 months. Time-to-progression was comparable among the low-, intermediate- and high-risk groups. Progression-free survival at 1.5 years was estimated to be at 78% for the high-risk group, 83% for the intermediate-risk group, and 86% for the low-risk group. At 1.5-years follow-up, no studied clinical or histopathologic factors of interest were shown significantly correlated with outcome.
Conclusion: Filipinas with Stage I-III breast cancer who completed chemotherapy showed a favorable 1.5-years progression-free survival, regardless of histopathologic profile, or St. Gallen risk stratification. Other factors (such as ER/PR/HER2neu profile, or compliance to schedule of treatment) that may contribute to disease progression need to be further explored; follow-up of these patients up to 5 or more years would define sustained gains from the DOH Breast Cancer Medicines Access Program.