Summary of included studies evaluating the prognostic value of ctDNA mutation status in HER2-targeted therapy for breast cancer.

This table summarizes the key characteristics of the 12 included studies investigating the association between ctDNA mutation status and PFS in patients receiving anti-HER2 therapies. Data include publication year, country, study type, clinical phase, treatment regimens, ctDNA mutation frequency, and HR comparing PFS between MT and WT ctDNA groups. Abbreviations: ctDNA, circulating tumor DNA; PFS, progression-free survival; HR, hazard ratio; CI, confidence interval; WT, wild type; MT, mutant type; RCT, randomized controlled trial; N/A, not available; Y, yes; N, no. *Note: Median PFS values are reported in months. Where available, HRs and 95% confidence intervals were extracted directly from the original publications. All HRs calculated with wild-type as reference; HR>1 indicates worse prognosis in mutation group. Studies varied in anti-HER2 regimens, including monoclonal antibodies, TKIs, and ADCs, as well as combination with chemotherapy or endocrine therapy.