Faculty Bibliography

PURPOSE/OBJECTIVE:EA1181 (ClinicalTrials.gov identifier: NCT04266249) is a single-arm trial evaluating neoadjuvant taxane, trastuzumab, and pertuzumab (THP) in patients with clinical stage II/IIIa human epidermal growth factor receptor 2 (HER2)-positive breast cancer. This report focuses on the secondary end points of pathologic complete response (pCR) rates and associated factors. The primary end point-3-year recurrence-free survival among patients achieving a pCR (ypT0/Tis, ypN0)-will be reported when data mature. METHODS:Patients received four cycles of trastuzumab and pertuzumab (HP) with either once per week paclitaxel (12 weeks) or docetaxel (every 3 weeks for four cycles), followed by surgery. Clinicopathologic characteristics were assessed in all patients. The HER2DX pCR score was determined using diagnostic biopsy samples in a representative subset. Logistic regression models identified factors associated with pCR. RESULTS:A total of 2,175 patients were enrolled (781 HER2+/estrogen receptor‑negative [ER-]; 1,394 HER2+/ER+). Of 2,141 patients who initiated THP, the overall pCR rate was 43.8%: 63.7% in HER2+/ER- and 32.4% in HER2+/ER+ tumors. Higher pCR rates were observed in tumors that were ER-negative or low ER expressing, progesterone receptor-negative or low expressing, HER2 immunohistochemistry (IHC) 3+, and in patients treated with once per week paclitaxel. T3 disease was associated with a lower pCR rate in HER2+/ER- tumors; otherwise, tumor (T) and nodal (N) stage did not significantly affect pCR. Among 569 patients assessed for HER2DX pCR scores, a high score was independently associated with higher pCR rates, after adjustment for clinicopathologic variables. CONCLUSION/CONCLUSIONS:Neoadjuvant THP achieved pCR in nearly two-thirds of patients with HER2+/ER- and one third with HER2+/ER+ breast cancer. Low hormone receptor expression, HER2 IHC 3+ status, once per week paclitaxel use, and a high HER2DX pCR score were independent predictors of pCR. These findings should help optimize risk stratification and treatment personalization for patients with HER2-positive breast cancer.

INTRODUCTION/BACKGROUND:Early lymph node (LN) metastasis often precedes systemic metastasis and corresponds with significantly inferior survival for patients diagnosed with early-stage breast cancer (EBC). To understand the biological pathways involved in early LN metastasis, differential gene expression (DGE) analysis compared large tumors without evidence of LN metastasis (pT2-3pN0) to small tumors with LN metastasis (pT1pN+). METHODS:This study included 2,349 patients with EBC who underwent MammaPrint and BluePrint testing as part of the FLEX (NCT03053193). DGE was performed between pT2-3pN0/pT1pN + and across their MP/BP subtypes. Immune deconvolution was assessed using gene-signature-based methods, complemented by conventional tumor-infiltrating lymphocyte (TIL) analyses on a representative subset of patients. RESULTS:Greater DGE was observed within the MammaPrint High Risk and BluePrint Luminal B subgroups compared to pathological stages. MammaPrint High Risk tumors saw 73 differentially expressed genes (DEGs), while 34 were found for Luminal B tumors. Gene set enrichment analysis (GSEA) of MammaPrint High Risk/Luminal B tumors showed upregulated proliferation pathways and downregulated epithelial-to-mesenchymal transition (EMT) and immune profiles in pT2-3pN0 vs. pT1pN+, respectively. Immune deconvolution analyses showed a higher abundance of T gamma delta cells and CD4 + Th1 cells and a lower abundance of T regulatory cells, M2 macrophages, and cancer-associated fibroblasts within pT2-3pN0 tumors. Conventional histological assessment revealed no significant differences in TILs. CONCLUSION/CONCLUSIONS:This study lays the groundwork for exploring mechanisms of LN metastasis in EBC and their relation to MammaPrint High Risk and Luminal B subtypes. These data support previous studies' association of LN metastasis with EMT and immune dysregulation.

PURPOSE:Provide real-world data regarding the risk for SARS-CoV-2 infection and mortality in breast cancer (BC) patients on active cancer treatment. METHODS:Clinical data were abstracted from the 3778 BC patients seen at a multisite cancer center in New York between February 1, 2020 and May 1, 2020, including patient demographics, tumor histology, cancer treatment, and SARS-CoV-2 testing results. Incidence of SARS-CoV-2 infection by treatment type (chemotherapy [CT] vs endocrine and/or HER2 directed therapy [E/H]) was compared by Inverse Probability of Treatment Weighting. In those diagnosed with SARS-CoV-2 infection, Mann-Whitney test was used to a assess risk factors for severe disease and mortality. RESULTS:Three thousand sixty-two patients met study inclusion criteria with 641 patients tested for SARS-COV-2 by RT-PCR or serology. Overall, 64 patients (2.1%) were diagnosed with SARS-CoV-2 infection by either serology, RT-PCR, or documented clinical diagnosis. Comparing matched patients who received chemotherapy (n = 379) with those who received non-cytotoxic therapies (n = 2343) the incidence of SARS-CoV-2 did not differ between treatment groups (weighted risk; 3.5% CT vs 2.7% E/H, P = .523). Twenty-seven patients (0.9%) expired over follow-up, with 10 deaths attributed to SARS-CoV-2 infection. Chemotherapy was not associated with increased risk for death following SARS-CoV-2 infection (weighted risk; 0.7% CT vs 0.1% E/H, P = .246). Advanced disease (stage IV), age, BMI, and Charlson's Comorbidity Index score were associated with increased mortality following SARS-CoV-2 infection (P ≤ .05). CONCLUSION:BC treatment, including chemotherapy, can be safely administered in the context of enhanced infectious precautions, and should not be withheld particularly when given for curative intent.