Concurrent epirubicin and trastuzumab use increases complete pathological response rate without additional cardiotoxicity in patients with human epidermal growth factor receptor 2-positive early breast cancer: A meta-regression analysis.

BACKGROUND: Due to cardiotoxicity concerns, the concurrent use of epirubicin and trastuzumab has not been fully studied. This study aimed to examine the cardiotoxicity and pathological complete response (pCR) rate associated with the concurrent regimens in patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer (EBC). METHODS: We conducted a systematic search for relevant literature in the NCBI/PubMed, the Cochrane database, and international conference abstracts for phase II or III randomized controlled trials between January 1, 2000, and February 28, 2021, focusing on the concurrent regimens in patients with HER2-positive EBC. To compare the risk of cardiotoxicity and the odds of the pCR rate, we performed linear meta-regression analyses to investigate the effects of multiple covariates. RESULTS: We analyzed 7 neoadjuvant trials involving the concurrent use of epirubicin and trastuzumab with 1797 patients. The median cumulative dose of epirubicin used was 300 mg/m2, with a total of 96 reported adverse cardiac events. The concurrent regimens did not result in a significant increase in cardiotoxicity compared to nonconcurrent regimens (risk ratio [RR] = 1.18, 95% confidence interval [CI] = 0.68-2.05). Compared with nonconcurrent or non-anthracycline-containing regimens, concurrent regimens were associated with a significant increase in the pCR rate (odds ratio = 1.48, 95% CI = 1.04-2.12). The linear fixed-effects meta-regression analysis indicated that in trials including more patients with hormone receptor-positive EBC, the RR of cardiotoxicity significantly increased with concurrent regimens, and the pCR rate became less significant. CONCLUSIONS: The combination of trastuzumab and a low dose of epirubicin positively impacted the pCR rate without a significant increase in cardiotoxicity. We recommend exploring concurrent regimens for HR-negative, HER2-positive tumors to enhance pCR rates, with caution advised for HR-positive tumors due to potential cardiotoxicity.

Interaction of base excision repair gene polymorphism and estrogen-DNA adducts in breast cancer risk among East Asian women.

PURPOSE: In East Asia, the incidence of breast cancer has been increasing rapidly, particularly among premenopausal women. An elevated ratio of estrogen-DNA adducts was linked to a higher risk of breast cancer. The present study explored the influence of the interaction between base excision repair (BER) gene polymorphisms and estrogen-DNA adducts on breast cancer risk. METHODS: We conducted a case-control study comprising healthy volunteers and individuals with benign breast disease (control arm, n = 176) and patients with invasive carcinoma or carcinoma in situ (case arm, n = 177). Genotyping for BER-related genes, including SMUG1, OGG1, ERCC5, and APEX1, was performed. A logistic regression model, incorporating interactions between gene polymorphisms, estrogen-DNA adduct ratio, and clinical variables, was used to identify the risk factors for breast cancer. RESULTS: Univariate analysis indicated marginal associations between breast cancer risk and APEX1 rs1130409 T > G (P = 0.057) and APEX1 rs1760944 T > G (P = 0.065). Multivariate regression analysis revealed significant associations with increased breast cancer risk for APEX1_rs1130409 (GT/GG versus TT) combined with a natural logarithmic value of the estrogen-DNA adduct ratio (estimated OR 1.164, P = 0.023) and premenopausal status with an estrogen-DNA adduct ratio > 2.93 (estimated OR 2.433, P = 0.001). CONCLUSION: APEX1_rs1130409 (GT/GG versus TT) polymorphisms, which are related to decreased BER activity, combined with an increased ratio of estrogen-DNA adducts, increase the risk of breast cancer in East Asian women.