Sequential neoadjuvant chemotherapy using pegylated liposomal doxorubicin and cyclophosphamide followed by taxanes with complete trastuzumab and pertuzumab treatment for HER2-positive breast cancer: A phase Ⅱ single-arm study

Objective: Despite cardiotoxicity overlap, the trastuzumab/pertuzumab and anthracycline combination remains crucial due to significant benefits. Pegylated liposomal doxorubicin(PLD), a less cardiotoxic anthracycline, was evaluated for efficacy and cardiac safety when combined with cyclophosphamide and followed by taxanes with trastuzumab/pertuzumab in human epidermal growth factor receptor-2(HER2)-positive early breast cancer(BC).Methods: In this multicenter, phase II study, patients with confirmed HER2-positive early BC received four cycles of PLD(30-35 mg/m^(2)) and cyclophosphamide(600 mg/m^(2)), followed by four cycles of taxanes(docetaxel,90-100 mg/m^(2) or nab-paclitaxel, 260 mg/m^(2)), concomitant with eight cycles of trastuzumab(8 mg/kg loading dose,then 6 mg/kg) and pertuzumab(840 mg loading dose, then 420 mg) every 3 weeks. The primary endpoint was total pathological complete response(tp CR, yp T0/is yp N0). Secondary endpoints included breast p CR(bp CR),objective response rate(ORR), disease control rate, rate of breast-conserving surgery(BCS), and safety(with a focus on cardiotoxicity).Results: Between May 27, 2020 and May 11, 2022, 78 patients were treated with surgery, 42(53.8%) of whom had BCS. After neoadjuvant therapy, 47 [60.3%, 95% confidence interval(95% CI), 48.5%-71.2%] patients achieved tp CR, and 49(62.8%) achieved bp CR. ORRs were 76.9%(95% CI, 66.0%-85.7%) and 93.6%(95% CI,85.7%-97.9%) after 4-cycle and 8-cycle neoadjuvant therapy, respectively. Nine(11.5%) patients experienced asymptomatic left ventricular ejection fraction(LVEF) reductions of ≥10% from baseline, all with a minimum value of >55%. No treatment-related abnormal cardiac function changes were observed in mean N-terminal pro-BNP(NT-pro BNP), troponin I, or high-sensitivity troponin.Conclusions: This dual HER2-blockade with sequential polychemotherapy showed promising activity with rapid tumor regression in HER2-positive BC. Importantly, this regimen showed an acceptable safety profile,especially a low risk of cardiac events, suggesting it as an attractive treatment approach with a favorable risk-benefit balance.

TP53-specific mutations serve as a potential biomarker for homologous recombination deficiency in breast cancer:a clinical next-generation sequencing study

Background:TP53 mutations and homologous recombination deficiency(HRD)occur frequently in breast cancer.However,the characteristics of TP53 pathogenic mutations in breast cancer patients with/without HRD are not clear.Methods:Clinical next-generation sequencing(NGS)of both tumor and paired blood DNA from 119 breast cancer patients(BRCA-119 cohort)was performed with a 520-gene panel.Mutations,tumor mutation burden(TMB),and genomic HRD scores were assessed from NGS data.NGS data from 47 breast cancer patients in the HRD test cohort were analyzed for further verification.Results:All TP53 pathogenic mutations in patients had somatic origin,which was associated with the protein expression of estrogen receptor and progestogen receptor.Compared to patients without TP53 pathologic mutations,patients with TP53 pathologic mutations had higher levels of HRD scores and different genomic alterations.The frequency of TP53 pathologic mutation was higher in the HRDhigh group(HRD score≥42)relative to that in the HRD-low group(HRD score<42).TP53 has different mutational characteristics between the HRD-low and HRD-high groups.TP53-specific mutation subgroups had diverse genomic features and TMB.Notably,TP53 pathogenic mutations predicted the HRD status of breast cancer patients with an area under the curve(AUC)of 0.61.TP53-specific mutations,namely HRD-low mutation,HRD-high mutation,and HRD common mutation,predicted the HRD status of breast cancer patients with AUC values of 0.32,0.72,and 0.58,respectively.Interestingly,TP53 HRD-high mutation and HRD common mutation combinations showed the highest AUC values(0.80)in predicting HRD status.Conclusions:TP53-specific mutation combinations predict the HRD status of patients,indicating that TP53 pathogenic mutations could serve as a potential biomarker for poly-ADP-ribose polymerase(PARP)inhibitors in breast cancer patients.