Pakistan Journal of Pharmaceutical Sciences

Abstract: Background: DFS differs markedly among breast cancer subtypes with varied chemotherapy and targeted therapy regimens, making optimal regimen selection critical. Objectives: To investigate the impact of diverse regimens on DFS across breast cancer molecular subtypes and identify the optimal therapeutic strategies. Methods: 106 breast cancer patients were stratified by subtype and treatment regimen and followed up for 3 years. Results: These are preliminary findings from a 3-year follow-up: the overall 3-year DFS rate was 78.30%. In HER2-positive individuals, the 3-year DFS rate of the AC-TH±P regimen (85.71%) was higher than that of the TH regimen (66.67%) with statistical significance (p=0.032), though the sample sizes in the partial HER2-positive subgroups were small and the results need to be verified with larger samples. In hormone receptor-positive individuals, the DFS rate of the AC-taxane regimen (83.33%) was higher than that of the TC regimen (72.73%) (p=0.045), dose-dense regimens outperformed conventional ones (86.84% vs 66.67%, p=0.033) and abemaciclib addition improved DFS in high relapse risk cases (90.91% vs 63.64%, p=0.024). In TNBC, dose-dense regimens showed higher DFS (72.73% vs 53.85%, p=0.040); capecitabine for high relapse risk and olaparib for BRCA1/2 mutations both significantly improved DFS (p<0.05). Multivariate analysis confirmed TNBC, positive lymph node metastasis and non-optimized regimens as independent DFS risk factors (all p<0.05). Conclusion: This preliminary 3-year follow-up study demonstrated that precision individualized treatment is necessary for each subtype of breast cancer: for HER2-positive breast cancer, the AC-TH±P regimen is preferred; for HR-positive breast cancer, a dose-dense AC-taxane regimen is recommended, with abemaciclib added for high recurrence risk; for TNBC, dose-dense chemotherapy, with capecitabine added for high recurrence risk and olaparib added for BRCA1/2 mutations, can significantly prolong DFS.All conclusions are preliminary due to the short 3-year follow-up period and require validation with longer-term follow-up and larger sample sizes.