Comparing Role of Two Chemotherapy Regimens, CMF and nthracycline-Based, on Breast Cancer Survival in the Eastern editerranean Region and Asia by Multivariate Mixed Effects Models: a Meta-Analysis


Purpose: To assess the role of two adjuvant chemotherapy regimens, anthracycline-based and CMF on diseasefree survival and overall survival breast cancer patients by meta-analysis approach in Eastern Mediterraneanand Asian countries to determine which is more effective and evaluate the appropriateness and efficiency of twodifferent proposed statistical models. Materials and
Methods: Survival curves were digitized and the survivalproportions and times were extracted and modeled to appropriate covariates by two multivariate mixed effectsmodels. Studies which reported disease free survival and overall survival curves for anthracycline-based orCMF as adjuvant chemotherapy that were published in English in the Eastern Mediterranean region and Asiawere included in this systematic review. The two transformations of survival probabilities (Ln (-Ln(S)) andLn(S/ (1-S))) as dependent variables were modeled by a multivariate mixed model to same covariates in orderto have precise estimations with high power and appropriate interpretation of covariate effects. The analysiswas carried out with SAS Proc MIXED and STATA software.
Results: A total of 32 studies from the publishedliterature were analysed, covering 4,092 patients who received anthracycline-based and 2,501 treated with CMFfor the disease free survival and in order to analyze the overall survival, 13 studies reported the overall survivalcurves in which 2,050 cases were treated with anthracycline-based and 1,282 with CMF regimens.
Conclusions:The findings illustrated that the model with dependent variable Ln (-Ln(S)) had more precise estimations of thecovariate effects and showed significant difference between the effects of two adjuvant chemotherapy regimens.Anthracycline-based treatment gave better disease free survival and overall survival. As an IPD meta-analysis inthe Italy the results of Angelo et al in 2011 also confirmed that anthracycline-based regimens were more effectivefor survival of breast cancer patients. The findings of Zare et al 2012 on disease free survival curves in Asia alsoprovided similar evidence.