No abstract

Purpose. Although trastuzumab is the standard of care for patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer (EBC), drug resistance and disease relapse occur. erefore, we performed a meta-analysis to assess the efficacy and safety of trastuzumab-containing dual anti-HER2 therapy compared to trastuzumab alone. Methods. A systematic search was performed to identify eligible randomized controlled trials (RCTs). Main outcomes including event-free survival/invasive disease-free survival (EFS/iDFS), overall survival (OS), and safety were considered. Results. Ten RCTs were included (15,284 patients). Significant improvements were observed in both EFS/iDFS (HR 0.86, p � 0.0003) and OS (HR 0.86, p � 0.02) with trastuzumab-based dual anti-HER2 therapy, especially in adjuvant treatment, while in the neoadjuvant setting, dual-targeted therapy also achieved a substantial pathological complete response (pCR) benefit (HR 1.34, p � 0.0002). Subgroup analysis revealed that the EFS/iDFS benefit was slightly higher with trastuzumab plus pertuzumab or plus neratinib than trastuzumab plus lapatinib, while OS benefit was significant with trastuzumab plus lapatinib, but there were no subgroup differences (interaction test, p � 0.80 and 0.24, resp.). In addition, EFS/iDFS benefit was unrelated to hormone receptor status but pronounced in the lymph node-positive (LN+) subgroup, which should be interpreted cautiously for lacking interaction (p � 0.18). Besides, patients receiving dual therapy, especially with the lapatinib-containing regimen, experienced more toxicity, but no increase in cardiotoxicity. Conclusions. Despite being associated with more toxicity, trastuzumab-containing dual anti-HER2 therapy is superior to trastuzumab single agent for HER2-positive EBC independent of hormone receptor status. e correlation between survival and LN status needs further verification. Trastuzumab plus pertuzumab or plus neratinib is the preferred regimen with substantial efficacy and lower toxicity.

IMPORTANCEStudies have shown that delayed initiation of surgery and adjuvant chemotherapy is associated with lower rates of breast cancer survival. However, it remains unclear whether delayed initiation of adjuvant hormone therapy (AHT) is associated with survival. OBJECTIVE To assess the association of time to adjuvant hormone therapy (TTH) with breast cancer survival and evaluate the factors associated with AHT. DESIGN, SETTING, AND PARTICIPANTS This cohort study examined data from the National Cancer Database from 2004 through 2014 to assess the association of TTH (stratified as Յ150 and >150 days) with cancer survival. All patients included were diagnosed with stage I to stage III hormone receptor-positive, human epidermal growth factor receptor-2 (ERBB2; formerly HER2)-negative invasive breast cancer and underwent AHT without chemotherapy. Data were analyzed from April 2019 to May 2020. EXPOSURES AHT was administered at different time points following surgical procedures for breast cancer treatment. MAIN OUTCOMES AND MEASURES An inverse probability of treatment weighting (IPTW) model was constructed to evaluate overall survival by adjusting for treatment facility, patient demographics, tumor characteristics, and treatment; multivariable logistic regression was conducted to assess factors associated with delayed treatment. RESULTS A total of 144 103 patients (median [IQR] follow-up, 36.6 months [25.5-49.2 months]; mean [SD] age, 63.7 [11.6] years) were identified, which included 142 916 (99.2%) women, 11 574 (8.0%) Black patients, and 126 013 (87.4%) White patients. Of these, 134 873 patients (93.6%) had a TTH of 150 days or less and 9230 patients (6.4%) had a TTH longer than 150 days. The IPTW-based Cox model demonstrated that patients with delayed AHT (ie, a TTH past 150 days) were associated with decreased survival (hazard ratio [HR], 1.31; 95% CI, 1.26-1.35; P < .001) compared with those receiving the timely treatment (TTH Յ150 days). Several sensitivity analyses (including IPTW with stabilized weight [