Lapatinib with trastuzumab for HER2-positive early breast cancer (NeoALTTO): survival outcomes of a randomised, open-label, multicentre, phase 3 trial and their association with pathological complete response

Comparison of paclitaxel and docetaxel in dual HER2 blockade: efficacy and safety in neoadjuvant treatment of HER2-positive breast cancer

BACKGROUND

Dual HER2 blockade with trastuzumab and pertuzumab combined with neoadjuvant chemotherapy improves outcomes in HER2-positive breast cancer. The optimal taxane backbone (paclitaxel vs. docetaxel) remains unclear.

METHODS

This retrospective study included 220 HER2-positive breast cancer patients treated with anthracycline-based chemotherapy followed by dual HER2 blockade with trastuzumab, pertuzumab, and either paclitaxel (80 mg/m2 for 12 weeks) or docetaxel (75 mg/m2 every three weeks for four cycles). Pathological complete response (pCR), disease-free survival (DFS), overall survival (OS), and toxicity profiles were analyzed.

RESULTS

At the time of diagnosis, 6% of the patients included in the study were at stage I, 70.4% were at stage II, and 23.6% were at stage III. The overall pCR rate was 55%, with no significant difference between the paclitaxel (57.9%) and docetaxel (52.2%) groups (p = 0.418). Higher pCR rates were associated with grade 3 tumors, ER/PR negativity, and Ki- 67 ≥ 20%. Patients achieving pCR had significantly lower relapse rates (2.5% vs. 16.2%, p < 0.001). These factors were significantly associated with pCR in univariate analysis but did not remain independent predictors in multivariate analysis. DFS and OS were higher in the paclitaxel group compared to the docetaxel group (DFS: 96.3% vs. 83.2%, p = 0.025; OS: 100% vs. 95.5%, p = 0.042). Grade 3-4 anemia was more frequent with docetaxel (23% vs. 9%, p = 0.007).

CONCLUSION

Both paclitaxel and docetaxel are effective in neoadjuvant dual HER2 blockade regimens. Paclitaxel demonstrated better DFS, OS, and a favorable safety profile, supporting its use as a preferred option.

Impact of Hormone Receptor Status and HER2 Expression on Neoadjuvant Targeted Therapy Response in HER2-Positive Breast Cancer: A Multicenter Retrospective Study

Previous studies indicate that HER2 protein expression and hormone receptor (HoR) status affect the sensitivity of HER2-positive breast cancer to neoadjuvant therapy, but it is unclear if sensitivity varies among subgroups defined by HER2 and HoR status. We examined 2 cohorts of patients, aged 18 to 80 years, with HER2-positive early breast cancer who underwent neoadjuvant therapy followed by surgery between January 1, 2009, and December 31, 2022: cohort 1 included 2648 patients, and cohort 2 had 141 patients with RNA expression data. Patients were divided into 4 groups based on immunohistochemical HER2 and HoR status: HER2(3+)/HoR-, HER2(3+)/HoR+, HER2(2+)/HoR-, and HER2(2+)/HoR+. We evaluated total pathological complete response (TpCR, defined as ypT0/is ypN0) rates, disease-free survival (DFS), and variations in PAM50 intrinsic subtypes across different subgroups. In cohort 1, HER2(3+)/HoR- had a higher TpCR rate (44.5%) than HER2(3+)/HoR+ (33.8%) (P < .001), HER2(2+)/HoR- (31.7%) (P = .013), and HER2(2+)/HoR+ (13.8%) (P < .001). DFS was similar across groups (P = .445). Trastuzumab or trastuzumab plus pertuzumab significantly improved TpCR rates and DFS in HER2(3+)/HoR- and HER2(3+)/HoR+ but not in HER2(2+)/HoR- and HER2(2+)/HoR+. Cohort 2 showed significant PAM50 subtype differences across these groups (P < .001). In conclusion, the responsiveness of HER2-positive breast cancer to neoadjuvant targeted therapy is significantly influenced by HER2 expression levels and HoR status, emphasizing the necessity of precision medicine approaches to tailor therapeutic strategies for improved clinical outcomes.

Prognostic value of residual disease (RD) biology and gene expression changes during the neoadjuvant treatment in patients with HER2-positive early breast cancer (EBC)

BACKGROUND

In human epidermal growth factor receptor 2 (HER2)-positive early breast cancer (EBC), we investigated tumor and immune changes during neoadjuvant treatment and their impact on residual disease (RD) biology and prognostic implications across four neoadjuvant studies of trastuzumab with or without lapatinib, and with or without chemotherapy: CALGB 40601, PAMELA, NeoALTTO, and NSABP B-41.

PATIENTS AND METHODS

We compared tumor and immune gene expression changes during neoadjuvant treatment and their association with event-free survival (EFS) by uni- and multivariable Cox regression models in different cohorts and timepoints: 452 RD samples at baseline including 169 with a paired RD, and biomarker changes during neoadjuvant therapy, evaluating model performance via the c-index.

RESULTS

Analysis of 169 paired tumor samples revealed a shift in intrinsic subtype proportions from HER2-enriched at baseline (50.3%) to normal-like (49.1%) followed by luminal A (18.9%) in RD. This luminal phenotypic change was supported by decreased correlation to the HER2-enriched centroid, ERBB2, and HER2 amplicon genes and increased correlation to the luminal A centroid (Wilcoxon test P < 0.001). Additionally, RD showed relative immune activation marked by significant increases in B-cell, CD8 T-cell, and natural killer cell signatures (Wilcoxon test P < 0.05). In multivariable Cox models, intrinsic subtypes at baseline provided more prognostic information, while immune gene expression signatures provided more prognostic information in RD. Notably, the best multivariable EFS model (c-index = 0.77) integrated the immunoglobulin G signature from RD samples (adjusted hazard ratio 0.45, 95% confidence interval 0.30-0.67, adjusted P = 0.002).

CONCLUSIONS

In patients with HER2-positive EBC and RD, tumor biomarkers provide more prognostic information at baseline. In contrast, immune biomarkers perform better for EFS prognosis in RD.

Oncologic Outcomes of Breast-Conserving Surgery in a Colombian Cancer Center: An Observational, Analytical, Retrospective Cohort Study

Background: Breast-conserving surgery (BCS) is one of the major surgical advances in breast cancer treatment. This study evaluated the oncological outcomes of BCS in patients with non-metastatic breast cancer at a referral cancer center in a medium-resource country between 2013 and 2019. Methods: An observational, analytical, retrospective cohort study was conducted on patients with stage I-IIIC breast cancer treated at the Instituto Nacional de Cancerología (Bogotá, Colombia) from September 2013 to March 2019. Demographic data, tumor characteristics, treatment types, and survival outcomes were retrospectively collected. Results: A total of 409 patients were included. In 64.1% of cases, BCS was performed as the initial treatment and in 35.9%, after neoadjuvant chemotherapy (NACT). With a median follow-up of 85.2 months, tumor recurrence was documented in 9.04% of patients, local recurrence in 2.9%, regional in 2.2%, and distant in 5.6%. The identified risk factors for mortality were a locally advanced clinical stage (HR 5.13; p = 0.01), triple-negative subtype (HR 8.02; p < 0.01), and nodal involvement of more than four lymph nodes in the surgical specimen (HR 4.00; p < 0.01). Conclusions: Breast-conserving surgery is an oncologically safe procedure for patients with early and locally advanced breast cancer who respond to NACT. The time to recurrence and overall survival are determined by the clinical stage, axillary tumor burden, and biological subtype of the disease.

Molecular classification of hormone receptor-positive /HER2-positive breast cancer reveals potential neoadjuvant therapeutic strategies

Significant heterogeneity exists in hormone receptor (HR)-positive/HER2-positive (HR+/HER2+) breast cancer, contributing to suboptimal pathological complete response rates with conventional neoadjuvant treatment regimens. Overcoming this challenge requires precise molecular classification, which is pivotal for the development of targeted therapies. We conducted molecular typing on a cohort of 211 patients with HR+/HER2+ breast cancer and performed a comprehensive analysis of the efficacy of various neoadjuvant treatment regimens. Our findings revealed four distinct molecular subtypes, each exhibiting unique characteristics and therapeutic implications. The HER2-enriched subtype, marked by activation of the HER2 signaling and hypoxia-inducible factor 1 (HIF-1) pathway, may benefit from intensified anti-HER2-targeted therapy. Estrogen receptor (ER)-activated subtype demonstrated potential sensitivity to combined therapeutic strategies targeting both ER and HER2 pathways. Characterized by high immune cell infiltration, the immunomodulatory subtype showed sensitivity to HER2-targeted antibody-drug conjugates (ADCs) and promise for immune checkpoint therapy. The highly heterogeneous subtype requires a multifaceted therapeutic approach. Organoid susceptibility assays suggested phosphoinositide 3-kinase inhibitors may be a potential treatment option. These findings underscore the importance of molecular subtyping in HR+/HER2+ breast cancer, offering a framework for developing precise and personalized treatment strategies. By addressing the heterogeneity of the disease, these approaches have the potential to optimize therapeutic outcomes and improve patient care.

Inactivation of necroptosis-promoting protein MLKL creates a therapeutic vulnerability in colorectal cancer cells

Mortality from colorectal cancer (CRC) is significant, and novel CRC therapies are needed. A pseudokinase MLKL typically executes necroptotic cell death, and MLKL inactivation protects cells from such death. However, we found unexpectedly that MLKL gene knockout enhanced CRC cell death caused by a protein synthesis inhibitor homoharringtonine used for chronic myeloid leukemia treatment. In an effort to explain this finding, we observed that MLKL gene knockout reduces the basal CRC cell autophagy and renders such autophagy critically dependent on the presence of VPS37A, a component of the ESCRT-I complex. We further found that the reason why homoharringtonine enhances CRC cell death caused by MLKL gene knockout is that homoharringtonine activates p38 MAP kinase and thereby prevents VPS37A from supporting autophagy in MLKL-deficient cells. We observed that the resulting inhibition of the basal autophagy in CRC cells triggers their parthanatos, a cell death type driven by poly(ADP-ribose) polymerase hyperactivation. Finally, we discovered that a pharmacological MLKL inhibitor necrosulfonamide strongly cooperates with homoharringtonine in suppressing CRC cell tumorigenicity in mice. Thus, while MLKL promotes cell death during necroptosis, MLKL supports the basal autophagy in CRC cells and thereby protects them from death. MLKL inactivation reduces such autophagy and renders the cells sensitive to autophagy inhibitors, such as homoharringtonine. Hence, MLKL inhibition creates a therapeutic vulnerability that could be utilized for CRC treatment.

Tumor-infiltrating lymphocytes in HER2-positive breast cancer: potential impact and challenges

INTRODUCTION

In this review, we evaluate the role of stromal tumor-infiltrating lymphocytes (sTILs) as a biomarker in human epidermal growth factor receptor 2 (HER2)-positive breast cancer, exploring the prognostic and predictive potential in various treatment settings.

METHODS

Data from multiple clinical trials in the early and metastatic settings, focusing on TILs' correlation with pathologic complete response (pCR), progression-free survival (PFS), and overall survival across early and metastatic HER2-positive breast cancer were summarized. This review also discusses TILs' assessment methods, interobserver variability, and emerging technologies to assess TILs.

RESULTS

TILs have been identified as a highly reproducible biomarker that predicts pCR in patients receiving neoadjuvant therapy and serves as a prognostic indicator for long-term outcomes in several breast cancer subtypes, including HER2-positive. Studies indicate that higher TIL levels correlate with better recurrence-free survival rates. Despite these findings, there is no consensus on the optimal TIL threshold for clinical decision making, and further research is required on how to incorporate TILs into routine clinical practice.

CONCLUSIONS

TILs represent a promising biomarker in HER2-positive breast cancer, particularly in early disease settings. This assessment could guide treatment de-escalation or intensification, tailoring therapies to individual patient profiles. Due to their prognostic importance, TILs can be added to pathology reports. However, further validation in clinical trials is essential for the widespread adoption of TILs in clinical practice.

Neoadjuvant pyrotinib and trastuzumab in HER2-positive breast cancer with no early response (NeoPaTHer): efficacy, safety and biomarker analysis of a prospective, multicentre, response-adapted study

The potential benefits of pyrotinib for patients with trastuzumab-insensitive, HER2-positive early-stage breast cancer remain unclear. This prospective, multicentre, response-adapted study evaluated the efficacy and safety of adding pyrotinib to the neoadjuvant treatment of HER2-positive breast cancer patients with a poor response to initial docetaxel plus carboplatin and trastuzumab (TCbH). Early response was assessed using magnetic resonance imaging (MRI) after two cycles of treatment. Patients showing poor response, as defined by RECIST 1.1, could opt to receive additional pyrotinib or continue standard therapy. The primary endpoint was the total pathological complete response (tpCR; ypT0/isN0) rate. Of the 129 patients enroled, 62 (48.1%) were identified as MRI-responders (cohort A), 26 non-responders continued with four more cycles of TCbH (cohort B), and 41 non-responders received additional pyrotinib (cohort C). The tpCR rate was 30.6% (95% CI: 20.6-43.0%) in cohort A, 15.4% (95% CI: 6.2-33.5%) in cohort B, and 29.3% (95% CI: 17.6-44.5%) in cohort C. Multivariable logistic regression analyses demonstrated comparable odds of achieving tpCR between cohorts A and C (odds ratio = 1.04, 95% CI: 0.40-2.70). No new adverse events were observed with the addition of pyrotinib. Patients with co-mutations of TP53 and PIK3CA exhibited lower rates of early partial response compared to those without or with a single gene mutation (36.0% vs. 60.0%, P = 0.08). These findings suggest that adding pyrotinib may benefit patients who do not respond to neoadjuvant trastuzumab plus chemotherapy. Further investigation is warranted to identify biomarkers predicting patients' benefit from the addition of pyrotinib.

Histamine N-methyltransferase (HNMT) as a potential auxiliary biomarker for predicting adaptability to anti-HER2 drug treatment in breast cancer patients

BACKGROUND

Up to 23% of breast cancer patients recurred within a decade after trastuzumab treatment. Conversely, one trial found that patients with low HER2 expression and metastatic breast cancer had a positive response to trastuzumab-deruxtecan (T-Dxd). This indicates that relying solely on HER2 as a single diagnostic marker to predict the efficacy of anti-HER2 drugs is insufficient. This study highlights the interaction between histamine N-methyltransferase (HNMT) and HER2 as an adjunct predictor for trastuzumab response. Furthermore, modulation of HER2 expression by HNMT may explain why those with low HER2 expression still respond to T-Dxd.

METHODS

We investigated the impact of HNMT protein expression on the efficacy of anti-HER2 therapy in both in vivo and ex vivo models of patient-derived xenografts and cell line-derived xenografts. Our analysis included Förster resonance energy transfer (FRET) to assess the interaction strength between HNMT and HER2 proteins in trastuzumab-resistant and sensitive tumor tissues. Additionally, we used fluorescence lifetime imaging microscopy (FLIM), cleaved luciferase, and immunoprecipitation to study the interaction dynamics of HNMT and HER2. Furthermore, we evaluated the influence of HNMT activity on the binding of anti-HER2 antibodies to their targets through flow cytometry. We also observed the nuclear translocation of HNMT/HER2-ICD cells using fluorescent double staining and DeltaVision microscopy. Finally, ChIP sequencing was employed to identify target genes affected by the HNMT/HER2-ICD complex.

RESULTS

This study highlights HNMT as a potential auxiliary biomarker for diagnosing HER2 + breast cancer. FRET analysis demonstrated a significant interaction between HNMT and HER2 protein in trastuzumab-sensitive tumor tissue (n = 50), suggesting the potential of HNMT as a predictor of treatment response. Mechanistic studies revealed that the interaction between HNMT and HER2 contributes to increased HER2 protein expression at the transcriptional level, thereby impacting the efficacy of anti-HER2 therapy. Furthermore, a subset of triple-negative breast cancers characterized by HNMT overexpression was found to be sensitive to HER2 antibody-drug conjugates such as T-Dxd.

CONCLUSIONS

These findings offer crucial insights for clinicians evaluating candidates for anti-HER2 therapy, especially for HER2-low breast cancer patients who could gain from T-Dxd treatment. Identifying HNMT expression could help clinicians pinpoint patients who would benefit from anti-HER2 therapy.

Endocrine treatment mechanisms in triple-positive breast cancer: from targeted therapies to advances in precision medicine

Triple-positive breast cancer (TPBC), defined by the co-expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), poses unique therapeutic challenges due to complex signaling interactions and resulting treatment resistance. This review summarizes key findings on the molecular mechanisms and cross-talk among ER, PR, and HER2 pathways, which drive tumor proliferation and resistance to conventional therapies. Current strategies in TPBC treatment, including endocrine and HER2-targeted therapies, are explored alongside emerging approaches such as immunotherapy and CRISPR/Cas9 gene editing. Additionally, we discuss the tumor microenvironment (TME) and its role in treatment resistance, highlighting promising avenues for intervention through combination therapies and predictive biomarkers. By addressing these interdependent pathways and optimizing therapeutic strategies, precision medicine holds significant potential for improving TPBC patient outcomes and advancing individualized cancer care.

The optimal neoadjuvant treatment strategy for HR+/HER2 + breast cancer: a network meta-analysis

The efficacy of neoadjuvant therapy varies significantly with hormone receptor (HR) status for patients with human epidermal growth factor receptor 2 (HER2) positive breast cancer (BC). Despite extensive research on HER2 + BC, the optimal neoadjuvant strategy for HR+/HER2 + BC remains inconclusive. This study aimed to identify the optimal neoadjuvant regimen for HR+/HER2 + BC treatment. We conducted a systematic search for trials comparing neoadjuvant regimens for HR+/HER2 + BC and a network meta-analysis. Odds ratios for pathological complete response (pCR) and hazard ratios for event-free survival (EFS) were calculated. Treatment regimens were ranked using the surface under the cumulative ranking curve. 20 trials with 2809 patients were included. In pCR analysis, three neoadjuvant regimens sequentially ranked at the top, namely those comprising T-DM1, pertuzumab with trastuzumab, and tyrosine kinase inhibitor with trastuzumab, demonstrating significantly higher pCR rates than monotherapies. In EFS analysis, pertuzumab with trastuzumab ranked the first while T-DM1 containing regimen ranked the last. Anthracycline-free regimens showed a marginally higher pCR rate than anthracycline-containing regimens, while carboplatin-containing regimens demonstrated a numerically higher pCR rate than carboplatin-free regimens. Significant heterogeneity was observed in endocrine therapy analysis, which may be caused by different strategies for incorporating endocrine therapy. In conclusion, trastuzumab plus pertuzumab stands out as the optimal neoadjuvant HER2-targeting regimen for HR+/HER2 + BC Furthermore, anthracycline-free carboplatin-containing chemotherapy emerges as a promising combination treatment. Further investigation is required to clarify the role of endocrine therapy in HR+/HER2 + BC to guide its clinical application.

De-escalated neoadjuvant weekly nab-paclitaxel with trastuzumab and pertuzumab versus docetaxel, carboplatin, trastuzumab, and pertuzumab in patients with HER2-positive early breast cancer (HELEN-006): a multicentre, randomised, phase 3 trial

BACKGROUND

A previous phase 2 trial showed promising outcomes for patients with HER2-positive early-stage breast cancer using neoadjuvant de-escalation chemotherapy with paclitaxel, trastuzumab, and pertuzumab. We aimed to evaluate the efficacy of weekly nab-paclitaxel compared with the standard regimen of docetaxel plus carboplatin, both with trastuzumab and pertuzumab, as neoadjuvant therapies for patients with HER2-positive breast cancer.

METHODS

HELEN-006 was a multicentre, randomised, phase 3 trial done at six hospitals in China. We enrolled patients aged 18-70 years with untreated, histologically confirmed stage II-III invasive HER2-positive breast cancer and an Eastern Cooperative Oncology Group performance status of 0 or 1. Using an interactive response system, patients were randomly assigned (1:1) under a permuted block randomisation scheme (block size of four), stratified by tumour stage, nodal status, and hormone receptor status. Patients received either intravenous nab-paclitaxel (125 mg/m2 on days 1, 8, and 15) for six 3-week cycles, or intravenous docetaxel (75 mg/m2 on day 1) plus intravenous carboplatin (area under the concentration-time curve 6 mg/mL per min on day 1) for six 3-week cycles. Both groups also received concurrent intravenous trastuzumab, with an initial loading dose of 8 mg/kg and a maintenance dose of 6 mg/kg on day 1, as well as intravenous pertuzumab with a loading dose of 840 mg and a maintenance dose of 420 mg on day 1. This report is the final analysis of the primary endpoint, pathological complete response (ypT0/is ypN0), analysed in all patients who started treatment (modified intention to treat). The trial is registered with ClinicalTrials.gov, NCT04547907, and follow-up of the adjuvant phase is ongoing.

FINDINGS

Between Sept 20, 2020, and March 1, 2023, 789 patients were screened for eligibility, 689 of whom were randomly assigned (343 to the nab-paclitaxel group and 346 to the docetaxel plus carboplatin group). All 689 patients were Asian women. 669 patients received at least one dose of the study treatment and were included in the full analysis set (332 in the nab-paclitaxel group and 337 in the docetaxel plus carboplatin group). Median age of the patients was 50 years (IQR 43-55). Median follow-up time was 26 months (IQR 19-32). 220 (66·3% [95% CI 61·2-71·4]) patients in the nab-paclitaxel group had a pathological complete response, compared with 194 (57·6% [52·3-62·9]) in the docetaxel plus carboplatin group (combined odds ratio 1·54 [95% CI 1·10-2·14]; stratified p=0·011). 100 (30%) patients in the nab-paclitaxel group and 128 (38%) in the docetaxel plus carboplatin group had grade 3-4 adverse events. The most common grade 3-4 adverse events were nausea (22 [7%] in the nab-paclitaxel group vs 76 [23%] in the docetaxel plus carboplatin group), diarrhoea (25 [8%] vs 55 [16%]), and neuropathy (43 [13%] vs eight [2%]). Serious drug-related adverse events were reported in three (1%) patients in the nab-paclitaxel group and five (2%) in the docetaxel plus carboplatin group. No treatment-related deaths were reported in either group.

INTERPRETATION

These findings might suggest a potential advantage of nab-paclitaxel combined with trastuzumab and pertuzumab compared with the standard regimen in neoadjuvant therapy for patients with HER2-positive early breast cancer, suggesting that this new combination might establish a new standard for neoadjuvant treatment in this patient population.

FUNDING

National Natural Science Foundation of China, and Science and Technology Research Projects of Henan Province, China.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

Diffusion-weighted imaging in addition to contrast-enhanced MRI in identifying complete response in HER2-positive breast cancer

OBJECTIVES

The aim of this study is to investigate the added value of diffusion-weighted imaging (DWI) to dynamic-contrast enhanced (DCE)-MRI to identify a pathological complete response (pCR) in patients with HER2-positive breast cancer and radiological complete response (rCR).

MATERIALS AND METHODS

This is a single-center observational study of 102 patients with stage I-III HER2-positive breast cancer and real-world documented rCR on DCE-MRI. Patients were treated between 2015 and 2019. Both 1.5 T/3.0 T single-shot diffusion-weighted echo-planar sequence were used. Post neoadjuvant systemic treatment (NST) diffusion-weighted images were reviewed by two readers for visual evaluation and ADCmean. Discordant cases were resolved in a consensus meeting. pCR of the breast (ypT0/is) was used to calculate the negative predictive value (NPV). Breast pCR-percentages were tested with Fisher's exact test. ADCmean and ∆ADCmean(%) for patients with and without pCR were compared using a Mann-Whitney U-test.

RESULTS

The NPV for DWI added to DCE is 86% compared to 87% for DCE alone in hormone receptor (HR)-/HER2-positive and 67% compared to 64% in HR-positive/HER2-positive breast cancer. Twenty-seven of 39 non-rCR DWI cases were false positives. In HR-positive/HER2-positive breast cancer the NPV for DCE MRI differs between MRI field strength (1.5 T: 50% vs. 3 T: 81% [p = 0.02]). ADCmean at baseline, post-NST, and ∆ADCmean were similar between patients with and without pCR.

CONCLUSION

DWI has no clinically relevant effect on the NPV of DCE alone to identify a pCR in early HER2-positive breast cancer. The added value of DWI in HR-positive/HER2-positive breast cancer should be further investigated taken MRI field strength into account.

CLINICAL RELEVANCE STATEMENT

The residual signal on DWI after neoadjuvant systemic therapy in cases with early HER2-positive breast cancer and no residual pathologic enhancement on DCE-MRI breast should not (yet) be considered in assessing a complete radiologic response.

KEY POINTS

Radiologic complete response is associated with a pathologic complete response (pCR) in HER2+ breast cancer but further improvement is warranted. No relevant increase in negative predictive value was observed when DWI was added to DCE. Residual signal on DW-images without pathologic enhancement on DCE-MRI, does not indicate a lower chance of pCR.

Identification of HER2-positive breast cancer molecular subtypes with potential clinical implications in the ALTTO clinical trial

In HER2-positive breast cancer, clinical outcome and sensitivity to HER2-targeted therapies are influenced by both tumor and microenvironment features. However, we are currently unable to depict the molecular heterogeneity of this disease with sufficient granularity. Here, by performing gene expression profiling in HER2-positive breast cancers from patients receiving adjuvant trastuzumab in the ALTTO clinical trial (NCT00490139), we identify and characterize five molecular subtypes associated with the risk of distant recurrence: immune-enriched, proliferative/metabolic-enriched, mesenchymal/stroma-enriched, luminal, and ERBB2-dependent. Additionally, we validate the biological profiles of the subtypes and explore their prognostic/predictive value in external cohorts, namely the NeoALTTO trial (NCT00553358), SCAN-B (NCT02306096), I-SPY2 (NCT01042379), METABRIC and TCGA. Immune-enriched tumors present better survival outcomes, in contrast to mesenchymal/stroma-enriched and proliferative/metabolic-enriched tumors, while luminal and ERBB2-dependent tumors are characterized by low and high rates of pathological complete response, respectively. Of note, these molecular subtypes provide the rationale for treatment approaches leveraging the heterogeneous biology of HER2-positive breast cancer.

Pyrotinib and trastuzumab combination treatment synergistically overcomes HER2 dependency in HER2-positive breast cancer: insights from the PHILA trial

BACKGROUND

The PHILA study suggests that pyrotinib, trastuzumab, and docetaxel significantly improved progression-free survival (PFS) compared with placebo, trastuzumab, and docetaxel in patients with untreated HER2-positive metastatic breast cancer. In this study, we aimed to investigate the synergistic mechanisms of pyrotinib plus trastuzumab and provide further insights for the PHILA trial.

METHODS

The in vitro activity of combination treatments was assessed through cell biological and biochemical experiments. The in vivo efficacy was evaluated in cell-derived xenografts, a TUBO tumour model, and one clinical case. Next-generation sequencing was performed on circulating tumour DNA (ctDNA) from patients in the PHILA trial.

FINDINGS

The combination of pyrotinib and trastuzumab more effectively inhibited cell growth than pyrotinib or trastuzumab alone in models of HER2-dependent breast cancer. It potentiated membrane HER2 ubiquitination and downregulation, which resulted in a comprehensive blockade of the HER2 signalling pathway. The pyrotinib-altered membrane HER2 levels had no significant effect on trastuzumab-mediated antibody-dependent cell-mediated cytotoxicity (ADCC). We further validated the synergistic mechanisms in TUBO tumours and one clinical case, rather than models of HCC1954 cells harbouring the PIK3CA H1047R mutation. Similarly, in our centre cohort of the PHILA study, patients with genetic alterations in the HER2 signalling cascade had significantly shorter median PFS than individuals with the wild-type pathway.

INTERPRETATION

Our findings underscore the robust synergy between pyrotinib and trastuzumab in overcoming HER2 dependency and provide a rationale for pyrotinib, trastuzumab, and docetaxel as one of the optimal choices for patients with untreated HER2-positive metastatic breast cancer, who are dependent on the HER2 signalling cascade.

FUNDING

This work was supported by the National Key Research and Development Program of China (2021YFF1201300), the National Natural Science Foundation of China (82172875), the CAMS Innovation Fund for Medical Sciences (CIFMS) (2022-I2M-2-001), and the Joint Innovative Fund of Beijing Natural Science Foundation and Changping District (L234004).

Dual HER2 inhibition: mechanisms of synergy, patient selection, and resistance

HER2-targeted therapies for patients with HER2+ breast cancer are rapidly evolving, offering a range of more complex and personalized treatment options. Currently, an array of anti-HER2 monoclonal antibodies, tyrosine kinase inhibitors and antibody-drug conjugates are administered, sometimes alongside chemotherapy or endocrine therapy, both in curative and palliative contexts. However, the heterogeneous nature of HER2+ breast cancer demands a deeper understanding of disease biology and its role in responsiveness to novel HER2-targeted agents, as well as non-HER2-targeted therapies, in order to optimize patient outcomes. In this Review, we revisit the mechanisms of action of HER2-targeted agents, examine the evidence supporting the use of dual HER2 blockade in patients with HER2-amplified tumours, and explore the role of biomarkers in guiding future treatment strategies. We also discuss potential implications for the future treatment of patients with HER2+ breast cancer.

PI3K Mutation Profiles on Exons 9 (E545K and E542K) and 20 (H1047R) in Mexican Patients With HER-2 Overexpressed Breast Cancer and Its Relevance on Clinical-Pathological and Survival Biological Effects

Background: Trastuzumab resistance is associated with overexpressing the human epidermal growth factor receptor 2 (HER-2), which results from the altered phosphoinositide 3-kinase (PI3K) pathway in breast cancer patients. Objective: We quantified the frequency of PI3K enzyme single and double-point mutations in Mexican patients with HER-2 overexpressing breast cancer and its association with clinical-pathological variables. Methods: We embedded HER-2 breast samples in paraffin from 60 patients, extracted their DNA, and evaluated PI3K mutations in 49 HER-2-positive breast tumors. We focused on mutations for one exon 20 (H1047R) and two exon 9 PI3K (E545K, E542K) hotspots and characterized them as single and double-point mutations. The mean patient follow-up was 86 months. Results: Of 49 patients who tested positive for HER-2 breast cancer, 14.28% showed mutations in PI3K, 71.42% single-point, and 28.56% double-point mutations. We found single-point mutations in H1047R (42.85%) and E545K (28.57%). Only two patients exhibited double-point mutations: one in E542K/E545K and another in H1047R/E545K (14.28% each). Although we observed lower survival in patients with mutations in PI3K, we did not find a significant association between these factors (p = 0.191). However, single and double-point mutations in PI3K were significantly associated with the clinical stages of diagnosis and tumor size (p = 0.027 and p = 0.04, respectively). Conclusion: Single and double-point mutations in PI3K are related to tumor size and advanced clinical-pathological traits in Mexican patients with HER-2 overexpression, and future molecular studies are necessary to understand these findings.

Role of textural and radiomic analysis parameters in predicting histopathological parameters of the tumor in breast cancer patients

INTRODUCTION

Texture and radiomic analysis characterizes the tumor's phenotype and evaluates its microenvironment in quantitative terms. This study aims to investigate the role of textural and radiomic analysis parameters in predicting histopathological factors in breast cancer patients.

MATERIALS AND METHODS

Two hundred and twelve primary breast cancer patients underwent 18 F-FDG PET/computed tomography for staging. The images were processed in a commercially available textural analysis software. ROI was drawn over the primary tumor with a 40% threshold and was processed further to derive textural and radiomic parameters. These parameters were then compared with histopathological factors of tumor. Receiver-operating characteristic analysis was performed with a P -value <0.05 for statistical significance. The significant parameters were subsequently utilized in various machine learning models to assess their predictive accuracy.

RESULTS

A retrospective study of 212 primary breast cancer patients was done. Among all the significant parameters, SUVmin, SUVmean, SUVstd, SUVmax, discretized HISTO_Entropy, and gray level co-occurrence matrix_Contrast were found to be significantly associated with ductal carcinoma type. Four parameters (SUVmin, SUVmean, SUVstd, and SUVmax) were significant in differentiating the luminal subtypes of the tumor. Five parameters (SUVmin, SUVmean, SUVstd, SUVmax, and SUV kurtosis) were significant in predicting the grade of the tumor. These parameters showcased robust capabilities in predicting multiple histopathological parameters when tested using machine learning algorithms.

CONCLUSION

Though textural analysis could not predict hormonal receptor status, lymphovascular invasion status, perineural invasion status, microcalcification status of tumor, and all the molecular subtypes of the tumor, it could predict the tumor's histologic type, triple-negative subtype, and score of the tumor noninvasively.

Shifting the Paradigm: The Transformative Role of Neoadjuvant Therapy in Early Breast Cancer

The use of neoadjuvant systemic therapy (NST) has become increasingly important in the treatment of breast cancer because of its various advantages. These include the ability to downstage tumors without compromising locoregional control and the potential to obtain valuable information about clinical and biological response to therapy with implications for individual prognoses. Surgical response assessment paves the way for response-adapted therapy, and pathological complete response (pCR; defined as ypT0/is ypN0) serves as an additional endpoint for drug development trials. Recommended NST regimens commonly consist of anthracyclines and taxane, with dose-dense anthracyclines and weekly paclitaxel often preferred, whenever feasible. For patients with human epidermal growth factor receptor-2 (HER2)-positive tumors, dual anti-HER2 therapy (trastuzumab and pertuzumab) is indicated together with NST in case of elevated risk of recurrence. For patients with triple-negative breast cancer (TNBC), adding carboplatin to NST correlates with improved pCR and survival rates, as does the addition of immune checkpoint inhibitors. For hormone receptor (HR)-positive/HER2-negative cancers, emerging data on NST including immune checkpoint inhibitors may elevate the significance of NST in high-risk luminal breast cancer. Here, we present a synthesis of the results from neoadjuvant clinical trials that aim at optimizing treatment options for patients with high-risk breast cancer.

Targeted multimodal synergistic therapy of drug-resistant HER2-positive breast cancer by pyrotinib-ICG self-assembled nanoparticles

Neoadjuvant targeted therapy combining targeted agents with chemotherapy significantly improve survival rates of patients suffering from human epidermal receptor (HER2)-positive breast cancer (BC) in early or locally advanced stages. However, approximately 50% of patients fail to achieve a pathological complete response. In response, targeted photothermal therapy (PTT) and photodynamic therapy (PDT) have emerged as effective strategies to bolster primary tumors treatment. In this context, we developed a novel nanodrug, referred to as "P/ICG", which comprised of a tyrosine-kinase inhibitor pyrotinib and the photosensitizer indocyanine green (ICG). This formulation was created for the targeted and multimodal synergistic therapy of HER2-positive BC. Upon irradiation with near-infrared light, ICG generates high levels of intracellular reactive oxygen species and elevated temperature, enhancing chemotherapy effects of pyrotinib. This synergistic action boosts a highly effective anticancer effect promoting the ferroptosis pathway, providing an efficient therapeutic strategy for treating HER2-positive BC.

Advancing Pancreatic Cancer Surgical Treatments and Proposal of New Approaches

Pancreatic cancer is a significant challenge in oncology due to its aggressive nature and complex management, leading to high mortality rates and a dismally low 5-year survival rate. Approximately 85% of cases manifest as adenocarcinoma, while endocrine tumors constitute less than 5%. Borderline resectable and locally advanced pancreatic cancers are particularly difficult to treat due to vascular involvement, which complicates complete resections and increases morbidity. Various therapeutic modalities aim to overcome these challenges and improve patient outcomes. Traditionally, upfront surgery was the standard for resectable tumors, with multimodal chemotherapy being central to treatment. Understanding surgical anatomy is pivotal in enhancing surgical outcomes and patient survival. Resectability challenges are several when seeking to achieve R0 resections, particularly for borderline resectable tumors. Various classification systems-the MD Anderson criteria, the NCCN criteria, the AHPA/SSAT/SSO consensus statement, and the Alliance definition-assess tumor involvement with major blood vessels, with the first of these systems being broadly accepted. Vascular staging integration is also important, with the Ishikawa staging system using preoperative imaging to assess venous involvement. Furthermore, neoadjuvant therapy enhances treatment effectiveness by addressing micro-metastatic disease early, increasing R0 resection chances, and downstaging tumors for optimal surgery. Insights from the Fox Chase Cancer Center's neoadjuvant treatment approach highlight the importance of a multidisciplinary strategy when advancing therapy and improving patient prognosis. This commentary, inspired by Dr. Sanjay S. Reddy's Keynote Conference during MedNews week, highlights current advancements and ongoing challenges in the treatment of pancreatic cancer, emphasizing the need for a comprehensive, multidisciplinary approach to improve outcomes.

Cost-utility and budget impact analysis of neoadjuvant dual HER2 targeted therapy for HER2-positive breast cancer in Sri Lanka

This study aimed to assess the cost-utility and budget impact of dual to single HER2 targeted neoadjuvant therapy for HER2-positive breast cancer in Sri Lanka. A five-health state Markov model with lifetime horizon was used to assess the cost-utility of neoadjuvant trastuzumab (T) plus pertuzumab (P) or lapatinib (L) compared to single therapy of T with chemotherapy (C), in public healthcare system and societal perspectives. Input parameters were estimated using local data, network meta-analysis, published reports and literature. Costs were adjusted to year 2021 (1USD = LKR194.78). Five-year budget impact for public healthcare system was assessed. Incremental cost-effectiveness ratios in societal perspective for neoadjuvantLTC plus adjuvantT (strategy 3), neoadjuvantPTC plus adjuvantT (strategy 2), neoadjuvantLTC plus adjuvantLT (strategy 5), and neoadjuvantPTC plus adjuvantPT (strategy 4) compared to neoadjuvantTC plus adjuvantT (strategy 1) were USD2716, USD5600, USD6878, and USD12127 per QALY gained, respectively. One GDP per-capita (USD3815) was considered as the cost-effectiveness threshold for the analysis. Even though only the ICER for strategy 3 was cost-effective, uncertainty of efficacy parameter was revealed. For strategy 2 neoadjuvant PTC plus adjuvant T, a 25% reduction of neoadjuvant regimen cost was required to be cost effective for use in early HER2 positive breast cancer.

Assessing risks and knowledge gaps on the impact of systemic therapies in early breast cancer on female fertility: A systematic review of the literature

The therapeutic landscape for early breast cancer (eBC) has expanded by introducing novel anticancer agents into clinical practice. During their reproductive years, women with eBC should be informed of the potential risk of premature ovarian insufficiency (POI) and infertility with the proposed systemic therapy. Although the topic of female fertility is becoming increasingly relevant in patients with cancer, limited information is available on the gonadotoxicity of new agents available for eBC treatment. Analyses from clinical trials and prospective data on ovarian function biomarkers are lacking. The purpose of this systematic review is to report the available preclinical and clinical data on female fertility risk with the use of the new agents that are part of clinical practice use or under development for eBC management. This review highlights the clear need to perform additional research efforts to improve our understanding on the gonoadtoxicity of new anticancer agents.

Clinicopathological and molecular predictors of [18F]FDG-PET disease detection in HER2-positive early breast cancer: RESPONSE, a substudy of the randomized PHERGain trial

BACKGROUND

The PHERGain study (NCT03161353) is assessing early metabolic responses to neoadjuvant treatment with trastuzumab-pertuzumab and chemotherapy de-escalation using a [18Fluorine]fluorodeoxyglucose-positron emission tomography ([18F]FDG-PET) and a pathological complete response-adapted strategy in HER2-positive (HER2+) early breast cancer (EBC). Herein, we present RESPONSE, a PHERGain substudy, where clinicopathological and molecular predictors of [18F]FDG-PET disease detection were evaluated.

METHODS

A total of 500 patients with HER2 + EBC screened in the PHERGain trial with a tumor size > 1.5 cm by magnetic resonance imaging (MRI) were included in the RESPONSE substudy. PET[-] criteria entailed the absence of  ≥ 1 breast lesion with maximum standardized uptake value (SUVmax) ≥ 1.5 × SUVmean liver + 2 standard deviation. Among 75 PET[-] patients screened, 21 with SUVmax levels < 2.5 were randomly selected and matched with 21 PET[+] patients with SUVmax levels ≥ 2.5 based on patient characteristics associated with [18F]FDG-PET status. The association between baseline SUVmax and [18F]FDG-PET status ([-] or [+]) with clinicopathological characteristics was assessed. In addition, evaluation of stromal tumor-infiltrating lymphocytes (sTILs) and gene expression analysis using PAM50 and Vantage 3D™ Cancer Metabolism Panel were specifically compared in a matched cohort of excluded and enrolled patients based on the [18F]FDG-PET eligibility criteria.

RESULTS

Median SUVmax at baseline was 7.2 (range, 1-39.3). Among all analyzed patients, a higher SUVmax was associated with a higher tumor stage, larger tumor size, lymph node involvement, hormone receptor-negative status, higher HER2 protein expression, increased Ki67 proliferation index, and higher histological grade (p < 0.05). [18F]FDG-PET [-] criteria patients had smaller tumor size (p = 0.014) along with the absence of lymph node involvement and lower histological grade than [18F]FDG-PET [+] patients (p < 0.01). Although no difference in the levels of sTILs was found among 42 matched [18F]FDG-PET [-]/[+] criteria patients (p = 0.73), [18F]FDG-PET [-] criteria patients showed a decreased risk of recurrence (ROR) and a lower proportion of PAM50 HER2-enriched subtype than [18F]FDG-PET[+] patients (p < 0.05). Differences in the expression of genes involved in cancer metabolism were observed between [18F]FDG-PET [-] and [18F]FDG-PET[+] criteria patients.

CONCLUSIONS

These results highlight the clinical, biological, and metabolic heterogeneity of HER2+ breast cancer, which may facilitate the selection of HER2+ EBC patients likely to benefit from [18F]FDG-PET imaging as a tool to guide therapy.

TRIAL REGISTRATION

Clinicaltrials.gov; NCT03161353; registration date: May 15, 2017.

Neoadjuvant anthracycline-based (5-FEC) or anthracycline-free (docetaxel/carboplatin) chemotherapy plus trastuzumab and pertuzmab in HER2 + BC patients according to their TOP2A: a multicentre, open-label, non-randomized phase II trial

PURPOSE

Previous studies have reported the benefit of dual HER2-targeting combined to neoadjuvant chemotherapy in HER2-amplified breast cancer (HER2 + BC). Moreover, besides the cardiac toxicity following their association to Trastuzumab, anthracyclines chemotherapy may not profit all patients. The NeoTOP study was designed to evaluate the complementary action of Trastuzumab and Pertuzumab, and the relevance of an anthracycline-based regimen according to TOP2A amplification status.

METHODS

Open-label, multicentre, phase II study. Eligible patients were aged ≥ 18 with untreated, operable, histologically confirmed HER2 + BC. After centralized review of TOP2A status, TOP2A-amplified (TOP2A+) patients received FEC100 for 3 cycles then 3 cycles of Trastuzumab (8 mg/kg then 6 mg/kg), Pertuzumab (840 mg/kg then 420 mg/kg), and Docetaxel (75mg/m2 then 100mg/m2). TOP2A-not amplified (TOP2A-) patients received 6 cycles of Docetaxel (75mg/m2) and Carboplatin (target AUC 6 mg/ml/min) plus Trastuzumab and Pertuzumab. Primary endpoint was pathological Complete Response (pCR) using Chevallier's classification. Secondary endpoints included pCR (Sataloff), Progression-Free Survival (PFS), Overall Survival (OS), and toxicity.

RESULTS

Out of 74 patients, 41 and 33 were allocated to the TOP2A + and TOP2A- groups respectively. pCR rates (Chevallier) were 74.4% (95%CI: 58.9-85.4) vs. 71.9% (95%CI: 54.6-84.4) in the TOP2A + vs. TOP2A- groups. pCR rates (Sataloff), 5-year PFS and OS were 70.6% (95%CI: 53.8-83.2) vs. 61.5% (95%CI: 42.5-77.6), 82.4% (95%CI: 62.2-93.6) vs. 100% (95%CI: 74.1-100), and 90% (95%CI: 69.8-98.3) vs. 100% (95%CI: 74.1-100). Toxicity profile was consistent with previous reports.

CONCLUSION

Our results showed high pCR rates with Trastuzumab and Pertuzumab associated to chemotherapy. They were similar in TOP2A + and TOP2A- groups and the current role of neoadjuvant anthracycline-based chemotherapy remains questioned.

TRIAL REGISTRATION NUMBER

NCT02339532 (registered on 14/12/14).

Tumor Intrinsic Subtypes and Gene Expression Signatures in Early-Stage ERBB2/HER2-Positive Breast Cancer: A Pooled Analysis of CALGB 40601, NeoALTTO, and NSABP B-41 Trials

Importance

Biologic features may affect pathologic complete response (pCR) and event-free survival (EFS) after neoadjuvant chemotherapy plus ERBB2/HER2 blockade in ERBB2/HER2-positive early breast cancer (EBC).

Objective

To define the quantitative association between pCR and EFS by intrinsic subtype and by other gene expression signatures in a pooled analysis of 3 phase 3 trials: CALGB 40601, NeoALTTO, and NSABP B-41.

Design, Setting, and Participants

In this retrospective pooled analysis, 1289 patients with EBC received chemotherapy plus either trastuzumab, lapatinib, or the combination, with a combined median follow-up of 5.5 years. Gene expression profiling by RNA sequencing was obtained from 758 samples, and intrinsic subtypes and 618 gene expression signatures were calculated. Data analyses were performed from June 1, 2020, to January 1, 2023.

Main Outcomes and Measures

The association of clinical variables and gene expression biomarkers with pCR and EFS were studied by logistic regression and Cox analyses.

Results

In the pooled analysis, of 758 women, median age was 49 years, 12% were Asian, 6% Black, and 75% were White. Overall, pCR results were associated with EFS in the ERBB2-enriched (hazard ratio [HR], 0.45; 95% CI, 0.29-0.70; P < .001) and basal-like (HR, 0.19; 95% CI, 0.04-0.86; P = .03) subtypes but not in luminal A or B tumors. Dual trastuzumab plus lapatinib blockade over trastuzumab alone had a trend toward EFS benefit in the intention-to-treat population; however, in the ERBB2-enriched subtype there was a significant and independent EFS benefit of trastuzumab plus lapatinib vs trastuzumab alone (HR, 0.47; 95% CI, 0.27-0.83; P = .009). Overall, 275 of 618 gene expression signatures (44.5%) were significantly associated with pCR and 9 of 618 (1.5%) with EFS. The ERBB2/HER2 amplicon and multiple immune signatures were significantly associated with pCR. Luminal-related signatures were associated with lower pCR rates but better EFS, especially among patients with residual disease and independent of hormone receptor status. There was significant adjusted HR for pCR ranging from 0.45 to 0.81 (higher pCR) and 1.21-1.94 (lower pCR rate); significant adjusted HR for EFS ranged from 0.71 to 0.94.

Conclusions and relevance

In patients with ERBB2/HER2-positive EBC, the association between pCR and EFS differed by tumor intrinsic subtype, and the benefit of dual ERBB2/HER2 blockade was limited to ERBB2-enriched tumors. Immune-activated signatures were concordantly associated with higher pCR rates and better EFS, whereas luminal signatures were associated with lower pCR rates.

MRI-guided optimisation of neoadjuvant chemotherapy duration in stage II-III HER2-positive breast cancer (TRAIN-3): a multicentre, single-arm, phase 2 study

BACKGROUND

Patients with stage II-III HER2-positive breast cancer have good outcomes with the combination of neoadjuvant chemotherapy and HER2-targeted agents. Although increasing the number of chemotherapy cycles improves pathological complete response rates, early complete responses are common. We investigated whether the duration of chemotherapy could be tailored on the basis of radiological response.

METHODS

TRAIN-3 is a single-arm, phase 2 study in 43 hospitals in the Netherlands. Patients with stage II-III HER2-positive breast cancer aged 18 years or older and a WHO performance status of 0 or 1 were enrolled. Patients received neoadjuvant chemotherapy consisting of paclitaxel (80 mg/m2 of body surface area on day 1 and 8 of each 21 day cycle), trastuzumab (loading dose on day 1 of cycle 1 of 8 mg/kg bodyweight, and then 6 mg/kg on day 1 on all subsequent cycles), and carboplatin (area under the concentration time curve 6 mg/mL per min on day 1 of each 3 week cycle) and pertuzumab (loading dose on day 1 of cycle 1 of 840 mg, and then 420 mg on day 1 of each subsequent cycle), all given intravenously. The response was monitored by breast MRI every three cycles and lymph node biopsy. Patients underwent surgery when a complete radiological response was observed or after a maximum of nine cycles of treatment. The primary endpoint was event-free survival at 3 years; however, follow-up for the primary endpoint is ongoing. Here, we present the radiological and pathological response rates (secondary endpoints) of all patients who underwent surgery and the toxicity data for all patients who received at least one cycle of treatment. Analyses were done in hormone receptor-positive and hormone receptor-negative patients separately. This trial is registered with ClinicalTrials.gov, number NCT03820063, recruitment is closed, and the follow-up for the primary endpoint is ongoing.

FINDINGS

Between April 1, 2019, and May 12, 2021, 235 patients with hormone receptor-negative cancer and 232 with hormone receptor-positive cancer were enrolled. Median follow-up was 26·4 months (IQR 22·9-32·9) for patients who were hormone receptor-negative and 31·6 months (25·6-35·7) for patients who were hormone receptor-positive. Overall, the median age was 51 years (IQR 43-59). In 233 patients with hormone receptor-negative tumours, radiological complete response was seen in 84 (36%; 95% CI 30-43) patients after one to three cycles, 140 (60%; 53-66) patients after one to six cycles, and 169 (73%; 66-78) patients after one to nine cycles. In 232 patients with hormone receptor-positive tumours, radiological complete response was seen in 68 (29%; 24-36) patients after one to three cycles, 118 (51%; 44-57) patients after one to six cycles, and 138 (59%; 53-66) patients after one to nine cycles. Among patients with a radiological complete response after one to nine cycles, a pathological complete response was seen in 147 (87%; 95% CI 81-92) of 169 patients with hormone receptor-negative tumours and was seen in 73 (53%; 44-61) of 138 patients with hormone receptor-positive tumours. The most common grade 3-4 adverse events were neutropenia (175 [37%] of 467), anaemia (75 [16%]), and diarrhoea (57 [12%]). No treatment-related deaths were reported.

INTERPRETATION

In our study, a third of patients with stage II-III hormone receptor-negative and HER2-positive breast cancer had a complete pathological response after only three cycles of neoadjuvant systemic therapy. A complete response on breast MRI could help identify early complete responders in patients who had hormone receptor negative tumours. An imaging-based strategy might limit the duration of chemotherapy in these patients, reduce side-effects, and maintain quality of life if confirmed by the analysis of the 3-year event-free survival primary endpoint. Better monitoring tools are needed for patients with hormone receptor-positive and HER2-positive breast cancer.

FUNDING

Roche Netherlands.

Integrated multiomic profiling of breast cancer in the Chinese population reveals patient stratification and therapeutic vulnerabilities

Molecular profiling guides precision treatment of breast cancer; however, Asian patients are underrepresented in publicly available large-scale studies. We established a comprehensive multiomics cohort of 773 Chinese patients with breast cancer and systematically analyzed their genomic, transcriptomic, proteomic, metabolomic, radiomic and digital pathology characteristics. Here we show that compared to breast cancers in white individuals, Asian individuals had more targetable AKT1 mutations. Integrated analysis revealed a higher proportion of HER2-enriched subtype and correspondingly more frequent ERBB2 amplification and higher HER2 protein abundance in the Chinese HR+HER2+ cohort, stressing anti-HER2 therapy for these individuals. Furthermore, comprehensive metabolomic and proteomic analyses revealed ferroptosis as a potential therapeutic target for basal-like tumors. The integration of clinical, transcriptomic, metabolomic, radiomic and pathological features allowed for efficient stratification of patients into groups with varying recurrence risks. Our study provides a public resource and new insights into the biology and ancestry specificity of breast cancer in the Asian population, offering potential for further precision treatment approaches.

International multidisciplinary consensus on the integration of radiotherapy with new systemic treatments for breast cancer: European Society for Radiotherapy and Oncology (ESTRO)-endorsed recommendations

Novel systemic therapies for breast cancer are being rapidly implemented into clinical practice. These drugs often have different mechanisms of action and side-effect profiles compared with traditional chemotherapy. Underpinning practice-changing clinical trials focused on the systemic therapies under investigation, thus there are sparse data available on radiotherapy. Integration of these new systemic therapies with radiotherapy is therefore challenging. Given this rapid, transformative change in breast cancer multimodal management, the multidisciplinary community must unite to ensure optimal, safe, and equitable treatment for all patients. The aim of this collaborative group of radiation, clinical, and medical oncologists, basic and translational scientists, and patient advocates was to: scope, synthesise, and summarise the literature on integrating novel drugs with radiotherapy for breast cancer; produce consensus statements on drug-radiotherapy integration, where specific evidence is lacking; and make best-practice recommendations for recording of radiotherapy data and quality assurance for subsequent studies testing novel drugs.

Hormone, Targeted, and Combinational Therapies for Breast Cancers: From Humans to Dogs

Breast cancer (BC) is the most frequent cancer in women. In female dogs, canine mammary gland tumor (CMT) is also the leading neoplasm. Comparative oncology indicates similar tumor behaviors between human BCs (HBCs) and CMTs. Therefore, this review summarizes the current research in hormone and targeted therapies and describes the future prospects for HBCs and CMTs. For hormone receptor-expressing BCs, the first medical intervention is hormone therapy. Monoclonal antibodies against Her2 are proposed for the treatment of Her2+ BCs. However, the major obstacle in hormone therapy or monoclonal antibodies is drug resistance. Therefore, increasing alternatives have been developed to overcome these difficulties. We systemically reviewed publications that reported inhibitors targeting certain molecules in BC cells. The various treatment choices for humans decrease mortality in females with BC. However, the development of hormone or targeted therapies in veterinary medicine is still limited. Even though some clinical trials have been proposed, severe side effects and insufficient case numbers might restrict further explorations. This difficulty highlights the urgent need to develop updated hormone/targeted therapy or novel immunotherapies. Therefore, exploring new therapies to provide more precise use in dogs with CMTs will be the focus of future research. Furthermore, due to the similarities shared by humans and dogs, well-planned prospective clinical trials on the use of combinational or novel immunotherapies in dogs with CMTs to obtain solid results for both humans and dogs can be reasonably anticipated in the future.

Management and Mechanisms of Diarrhea Induced by Tyrosine Kinase Inhibitors in Human Epidermal Growth Factor Receptor-2-Positive Breast Cancer

Breast cancer has the highest incidence among female malignancies, significantly impacting women's health. Recently, numerous HER2-targeted therapies have achieved excellent clinical outcomes. Currently, anti-HER2 drugs are divided into three main categories: monoclonal antibodies, small-molecule tyrosine kinase inhibitors, and antibody-coupled drugs (ADCs). The main toxic side effects of small molecule TKI-based therapy are diarrhea, hand-foot syndrome, rash, nausea, and vomiting. Diarrhea is a potential predictor of tumor response, affecting up to 95% of cancer patients treated with TKIs. Severe gastrointestinal toxicity can result in the need for dose reductions and treatment interruptions. This not only compromises the efficacy of TKIs but also deteriorates human nutrition and quality of life. The majority of individuals develop diarrhea within 7 days of starting treatment, with approximately 30% developing grade 3 or higher diarrhea within 2-3 days of starting treatment. The severity of diarrhea typically correlates with the dosage of most TKIs. Current prevention and management strategies are primarily empirical, focusing on symptom alleviation rather than addressing the toxicological mechanisms underlying TKI-induced diarrhea. Consequently, anti-diarrheal drugs are often less effective in managing this condition in cancer patients receiving TKIs. Moreover, our understanding of the toxicological mechanisms responsible for such diarrhea remains limited, underscoring the urgent need to identify these mechanisms in order to develop effective anti-diarrheal medications tailored to this specific context. This review aims to elucidate management approaches and mechanisms for diarrhea induced by TKIs during HER2-positive breast cance.

The Efficacy and Safety of Inetetamab and Pyrotinib in Combination with Vinorelbine for Second-line Therapy and Beyond in HER2-positive Metastatic Breast Cancer: A Single-institution Clinical Experience

BACKGROUND AND OBJECTIVES

This study aimed to observe the efficacy and safety of inetetamab and pyrotinib in combination with vinorelbine in second-line therapy and beyond in HER2-positive metastatic breast cancer (MBC).

METHODS

Patients with HER2-positive MBC admitted to our hospital from January 2016 to December 2021 were selected. For patients who could not receive antibody‒drug conjugates (ADCs) during second-line (2nd-line) or third-line and beyond (≥ 3rd-line) anti-HER2 therapy, inetetamab + pyrotinib + vinorelbine was used for treatment until unacceptable adverse events occurred or the disease progressed, as evaluated by the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 every 2 cycles. The progression-free survival (PFS), objective response rate (ORR), clinical benefit rate (CBR), and adverse reactions were recorded. Multivariate Cox regression analysis was performed to explore the prognostic factors influencing the curative effect.

RESULTS

Overall, 52 patients were included; 13 patients received 2nd-line treatment, and 39 patients received ≥ 3rd-line treatment. The median PFS (mPFS) for all patients treated with inetetamab + pyrotinib + vinorelbine was 7 months. The mPFS of the 2nd-line subgroup was significantly better than that of the ≥ 3rd-line subgroup (17 vs. 5 months, P = 0.001). The mPFS of the subgroups that received trastuzumab (H) or trastuzumab and pertuzumab (HP) only was significantly better than that of the H or HP and tyrosine kinase inhibitor (TKI) subgroups (8 vs. 5 months, P = 0.030). The mPFS of the HER2 resistance subgroup was better than that of the HER2 refractoriness subgroup (14 vs. 7 months, P = 0.025). Cox regression analysis showed that the treatment line (2nd-line more so than ≥ 3rd-line) was an independent prognostic factor for PFS. In addition, the ORR and CBR of 2nd-line patients were significantly higher than those of ≥ 3rd-line patients (69.2% vs. 30.8% and 92.3% vs. 64.1%, respectively). The most common hematological toxicities were leukopenia and neutropenia, and the most common nonhematological toxicity was diarrhea.

CONCLUSION

Inetetamab and pyrotinib in combination with vinorelbine have good efficacy in ≥ 2nd-line treatment of HER2-positive MBC with controllable toxicity, and the combination is a new treatment option, especially for patients who cannot use ADCs in 2nd-line treatment.

Novel HER-2 Targeted Therapies in Breast Cancer

Human epidermal growth factor 2 (HER-2)-positive breast cancer represents 15-20% of all breast cancer subtypes and has an aggressive biological behavior with worse prognosis. The development of HER-2-targeted therapies has changed the disease's course, having a direct impact on survival rates and quality of life. Drug development of HER-2-targeting therapies is a prolific field, with numerous new therapeutic strategies showing survival benefits and gaining regulatory approval in recent years. Furthermore, the acknowledgement of the survival impact of HER-2-directed therapies on HER-2-low breast cancer has contributed even more to advances in the field. The present review aims to summarize the newly approved therapeutic strategies for HER-2-positive breast cancer and review the new and exploratory HER-2-targeted therapies currently under development.

Prognostic Factors and Survival Outcomes of Patients With Early HER2+ Breast Cancer Treated With Trastuzumab in a Brazilian Public Reference Center: A Real-World Study

PURPOSE

Trastuzumab was introduced into the Brazilian public health care service for early breast cancer (BC) in 2012. This study describes the survival outcomes and prognostic factors related to early HER2+ BC treatment in a Brazilian reference cancer center.

PATIENTS AND METHODS

This were a retrospective, single-center, observational study of early HER2+ BC patients treated with trastuzumab in the (neo)adjuvant setting between 2012 and 2018 at Hospital Pérola Byington. Demographic, clinical, disease-free survival (DFS) and overall survival (OS) data were evaluated. Multivariate analysis was performed to assess independent prognostic factors.

RESULTS

One hundred seventy-six and 353 patients treated in the neoadjuvant and adjuvant setting were included, respectively. The 3- and 5-year OS rates were 79% and 56% for the neoadjuvant group and 97% and 92% for the adjuvant group, respectively. Node positivity at diagnosis predicted poor OS for both groups. In the neoadjuvant group, stage III disease at diagnosis, delayed surgery, and lack of pathological complete response (pCR) predicted poor prognosis. The 3- and 5-year DFS rates were 67% and 46% in the neoadjuvant group and 91% and 86% in the adjuvant group, respectively. Histological grade 2, stage III disease at diagnosis, and lack of pCR predicted poor DFS for the neoadjuvant group. For the adjuvant group, node positivity at diagnosis predicted poor DFS.

CONCLUSION

Our results reveal multiple clinical parameters affecting survival outcomes according to the treatment setting. Patients treated with neoadjuvant therapy have a poor prognosis since they present with more advanced disease, indicating the importance of early diagnosis and optimized treatment.

Association of PIK3CA Mutation With Pathologic Complete Response and Outcome by Hormone Receptor Status and Intrinsic Subtype in Early-Stage ERBB2/HER2-Positive Breast Cancer

Importance

PIK3CA mutations may be associated with outcomes of patients with ERBB2/HER2-positive early breast cancer (EBC).

Objectives

To assess if PIK3CA mutations among patients with ERBB2/HER2-positive EBC are associated with treatment response and outcome, and if these associations vary by hormone receptor (HR) status or intrinsic molecular subtype (IMS).

Design, Setting, and Participants

This cohort study derived data on 184 patients from the phase 3 neoadjuvant Cancer and Leukemia Group B (CALGB) 40601 trial that enrolled patients with ERBB2/HER2-positive EBC in North America between January 1, 2008, and December 31, 2012. Participants received neoadjuvant paclitaxel with trastuzumab, lapatinib, or both. Statistical analysis was performed from March 23, 2022, to March 9, 2023.

Exposures

Gene expression profiling by RNA sequencing with Prediction Analysis of Microarray 50-determined IMS and PIK3CA mutations from whole-exome sequencing were obtained from pretreatment biopsies from 184 of 305 trial participants.

Main Outcomes and Measures

The primary end point was pathologic complete response (pCR) and the secondary end point of event-free survival (EFS). The association of PIK3CA mutations with pCR and EFS by HR status and IMS was estimated using logistic and Cox proportional hazards regression models.

Results

All 184 participants were women, with a median age of 49 years (range 24-75 years). A total of 121 participants (66%) had clinical stage II tumors; 32 (17%) had PIK3CA mutations, most frequently H1047R (38% [12 of 32]) and E545K (22% [7 of 32]). PIK3CA mutations were present in 20 of 102 cases of HR-positive EBC (20%) and 12 of 82 cases HR-negative EBC (15%) and varied by IMS (luminal B, 9 of 25 [36%]; luminal A, 2 of 21 [10%]; and ERBB2/HER2-enriched tumors, 19 of 102 [19%]). Pathologic complete response rates were lower in PIK3CA mutated than PIK3CA wild type in the overall population (34% [11 of 32] vs 49% [74 of 152]; P = .14) and were significantly different among those receiving trastuzumab (30% [7 of 23] vs 54% [63 of 117]; P = .045). At a median follow-up of 9 years, PIK3CA mutations were significantly associated with worse EFS in the overall cohort (hazard ratio, 2.58 [95% CI, 1.24-5.35]; P = .01), which persisted in a multivariable model including pCR, HR status, stage, and IMS (hazard ratio, 2.52 [95% CI, 1.16-5.47]; P = .02). The negative association of PIK3CA mutation was significant in HR-positive (hazard ratio, 3.60 [95% CI, 1.45-8.96]; P = .006) and luminal subtypes (hazard ratio, 4.84 [95% CI, 1.08-21.70]; P = .04), but not in nonluminal and HR-negative tumors.

Conclusions and Relevance

In ERBB2/HER2-positive EBC, PIK3CA mutations were associated with lower pCR rates and independently associated with worse long-term EFS. These findings appear to be associated with PIK3CA mutations in HR-positive and luminal EBC.

Immunological and clinicopathological features predict HER2-positive breast cancer prognosis in the neoadjuvant NeoALTTO and CALGB 40601 randomized trials

The identification of prognostic markers in patients receiving neoadjuvant therapy is crucial for treatment optimization in HER2-positive breast cancer, with the immune microenvironment being a key factor. Here, we investigate the complexity of B and T cell receptor (BCR and TCR) repertoires in the context of two phase III trials, NeoALTTO and CALGB 40601, evaluating neoadjuvant paclitaxel with trastuzumab and/or lapatinib in women with HER2-positive breast cancer. BCR features, particularly the number of reads and clones, evenness and Gini index, are heterogeneous according to hormone receptor status and PAM50 subtypes. Moreover, BCR measures describing clonal expansion, namely evenness and Gini index, are independent prognostic factors. We present a model developed in NeoALTTO and validated in CALGB 40601 that can predict event-free survival (EFS) by integrating hormone receptor and clinical nodal status, breast pathological complete response (pCR), stromal tumor-infiltrating lymphocyte levels (%) and BCR repertoire evenness. A prognostic score derived from the model and including those variables, HER2-EveNT, allows the identification of patients with 5-year EFS > 90%, and, in those not achieving pCR, of a subgroup of immune-enriched tumors with an excellent outcome despite residual disease.

Real world data on the demographic and clinicopathological profile and management of patients with early-stage HER2-positive breast cancer and residual disease treated with adjuvant trastuzumab emtansine (KARMA study)

INTRODUCTION

Trastuzumab emtansine (T-DM1) significantly improves invasive disease-free survival and reduces the risk of recurrence in patients with HER2-positive early breast cancer (EBC) with residual disease (RD). The KARMA study aimed to describe the characteristics and management of these patients in clinical practice in Spain.

MATERIAL AND METHODS

We conducted a multicentre retrospective study in patients with HER2-positive EBC with RD following neoadjuvant treatment (NeoT) and who had received ≥1 dose of T-DM1 as adjuvant treatment. The primary endpoint was the evaluation of sociodemographic and clinicopathological characteristics of these patients.

RESULTS

A total of 114 patients were included (March-July 2020). At diagnosis, most tumours were infiltrating ductal carcinoma (IDC) (93.9 %), grade 2 (56.1 %), and hormone receptor (HR)-positive (79.8 %). Over 75 % of patients had disease in operable clinical stages (T1-3 N0-1). In the neoadjuvant setting, 86.8 % of patients received trastuzumab plus pertuzumab, and 23.6 % achieved radiological complete response. Breast-conserving surgery was performed in 55.8 % of patients. Surgical specimens showed that 89.5 % of patients had IDC, 49.1 % grade 2, 84.1 % HR-positive, and 8.3 % HER2-negative disease. Most patients had RD classified as RCB-II and Miller/Payne grade 3/4. Grade 3 treatment-related adverse events (trAEs) occurred in 5.3 % of patients. No grade 4/5 AEs occurred. Over 95 % of patients were free of invasive-disease during T-DM1 adjuvant treatment.

CONCLUSION

The KARMA study describes the characteristics of patients with HER2-positive EBC with RD after NeoT and the real-life management of a T-DM1 adjuvant regimen, which showed a manageable safety profile in line with the KATHERINE trial data.

Dose-sparing effect of lapatinib co-administered with a high-fat enteral nutrition emulsion: preclinical pharmacokinetic study

Background

Lapatinib is an oral small-molecule tyrosine kinase inhibitor indicated for advanced or metastatic HER2-positive breast cancer. In order to reduce the treatment cost, a high-fat enteral nutrition emulsion TPF-T was selected as a dose-sparing agent for lapatinib-based therapies. This study aimed to investigate the effect of TPF-T on lapatinib pharmacokinetics.

Methods

First, a simple and rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed to quantitatively evaluate lapatinib in rabbit plasma. The method was fully validated according to the China Pharmacopoeia 2020 guidance. Rabbits and rats were chosen as the animal models due to their low and high bile flows, respectively. The proposed LC-MS/MS method was applied to pharmacokinetic studies of lapatinib, with or without TPF-T, in rabbit and rat plasma.

Results

The LC-MS/MS method revealed high sensitivity and excellent efficiency. In the rabbit model, co-administration with TPF-T resulted in a 32.2% increase in lapatinib exposure. In the rat model, TPF-T had minimal influence on the lapatinib exposure. In both models, TPF-T was observed to significantly elevate lapatinib concentration in the absorption phase.

Conclusion

Co-administration with TPF-T had a moderate effect on increasing exposure to lapatinib. Dose sparing using a high-fat liquid diet is potentially feasible for lapatinib-based therapies.

Crofelemer for the Management of Neratinib-Associated Diarrhea in Patients With HER2+ Early-Stage Breast Cancer

BACKGROUND

To evaluate the efficacy of crofelemer, a first in class anti-secretory anti-diarrheal agent, to manage neratinib-induced diarrhea in patients with early-stage breast cancer taking adjuvant neratinib.

PATIENTS AND METHODS

This single center, open label trial enrolled patients with Stage 2 to 3 HER2+ breast cancer taking adjuvant neratinib. One cohort took prophylactic crofelemer 125 mg bid and loperamide in the first 2 cycles, and as needed in subsequent cycles. The second cohort took dose-escalated neratinib with loperamide as needed (DE cohort). The primary endpoint was incidence of grade ≥ 3 diarrhea in the first 2 cycles.

RESULTS

Seven patients in the crofelemer cohort and 4 in the DE cohort were enrolled. In the first 2 cycles, 2 patients (29%) in the crofelemer cohort and 2 patients (50%) in the DE cohort experienced grade 3 diarrhea lasting 1 day on average. After cycle 2, no additional patients in either cohort had grade 3 diarrhea. Five of 7 patients controlled diarrhea with crofelemer alone. There were no grade 4 diarrhea events in either cohort. Three patients in the crofelemer cohort dose-reduced neratinib due to diarrhea in the first 2 cycles. Patients in the crofelemer cohort had an average of 0.58 diarrhea episodes/day. 82% experienced constipation, all grade 1.

CONCLUSIONS

This is the first study to investigate crofelemer for neratinib-induced diarrhea and demonstrates crofelemer activity in this setting. Further investigation of crofelemer for diarrhea secondary to cancer treatment is needed.

Potential Biomarkers Associated with Prognosis and Trastuzumab Response in HER2+ Breast Cancer

Breast cancer (BC) is the most common malignancy among women worldwide. Around 15-25% of BC overexpress the human epidermal growth factor receptor 2 (HER2), which is associated with a worse prognosis and shortened disease-free survival. Therefore, anti-HER2 therapies have been developed, such as monoclonal antibodies (trastuzumab, Tz), antibody-drug conjugates (ado-trastuzumab emtansine, T-DM1), and pharmacological inhibitors of tyrosine kinase activity (lapatinib, Lp). Although Tz, the standard treatment, has significantly improved the prognosis of patients, resistance still affects a significant population of women and is currently a major challenge in clinical oncology. Therefore, this study aims to identify potential biomarkers to predict disease progression (prognostic markers) and the efficacy of Tz treatment (predictive markers) in patients with HER2+ BC. We hypothesize that proteins involved in cell motility are implicated in Tz-resistance. We aim to identify alterations in Tz-resistant cells to guide more efficient oncologic decisions. By bioinformatics, we selected candidate proteins and determined how their expression, localization, and the process they modulate were affected by anti-HER2 treatments. Next, using HER2+ BC patients' data, we assessed these proteins as prognostic and predictive biomarkers. Finally, using Tz-resistant cells, we evaluated their roles in Tz response. We identified deregulated genes associated with cell motility in Tz/T-DM1-resistant vs. -sensitive cells. We showed that Tz, T-DM1, and Lp decrease cell viability, and their effect is enhanced in combinations. We determined synergism between Tz/T-DM1 and Lp, making possible a dose reduction of each drug to achieve the same therapeutic effect. We found that combinations (Tz/T-DM1 + Lp) efficiently inhibit cell adhesion and migration. Furthermore, we demonstrated the induction of FAK nuclear and cortactin peri-nuclear localization after T-DM1, Lp, and Tz/T-DM1 + Lp treatments. In parallel, we observed that combined treatments downregulate proteins essential for metastatic dissemination, such as SRC, FAK, and paxillin. We found that low vinculin (VCL) and cortactin (CTTN) mRNA expression predicts favorable survival rates and has diagnostic value to discriminate between Tz-sensible and Tz-resistant HER2+ BC patients. Finally, we confirmed that vinculin and cortactin are overexpressed in Tz-resistance cells, SKBR3-RTz. Moreover, we found that Tz plus FAK/paxillin/cortactin-silencing reduced cell adhesion/migration capacity in Tz-sensitive and -resistant cells. In conclusion, we demonstrate that combined therapies are encouraging since low doses of Tz/T-DM1 + Lp inhibit metastatic processes by downregulating critical protein expression and affecting its subcellular localization. We propose that vinculin and cortactin might contribute to Tz-sensibility/resistance in BC cells. Finally, we identify potential prognostic and predictive biomarkers that are promising for personalized BC management that would allow efficient patient selection in order to mitigate resistance and maximize the safety and efficacy of anti-HER2 therapies.

Ten-Year Oncologic Outcomes in T1-3N1 Breast Cancer After Targeted Axillary Sampling: A Retrospective Study

BACKGROUND

Targeted axillary sampling (TAS) is a new surgical concept for the assessment of axillary lymph node status in breast cancer that is hypothesized to be more effective at minimizing postoperative morbidities than axillary lymph node dissection (ALND), provided the metastatic axillary lymph node can be accurately detected without missing data; however, the oncologic outcomes over long-term follow-up have not been sufficiently investigated. This was a retrospective analysis to evaluate the 10-year oncologic outcomes in T1-3N1 breast cancer after TAS.

METHODS

Between 2008 and 2013, 230 female patients with cT1-3N1 breast cancer underwent breast and axillary surgery (ALND, n = 171; TAS, n = 59) at our institute. After TAS was applied, additional axillary radiotherapy was performed. Various postoperative complications, including postoperative seroma, lymphedema, and 10-year oncological outcomes, were evaluated and compared between the ALND and TAS groups.

RESULTS

Although overall survival during the 10-year follow-up period was better in the TAS group, there was no statistically significant difference in oncologic outcomes, including locoregional recurrence, distant metastasis, and overall survival (p = 0.395, 0.818, and 0.555, respectively). Furthermore, the incidence of lymphedema on the ipsilateral arm was significantly higher in the ALND group (p < 0.001).

CONCLUSIONS

The 10-year oncological outcomes of TAS were not inferior to those of conventional ALND in T1-3N1 breast cancers; however, the incidence of lymphedema was significantly higher in the ALND group.

Changing the role of pCR in breast cancer treatment - an unjustifiable interpretation of a good prognostic factor as a "factor for a good prognosis"

Pathologic complete response (pCR) after neoadjuvant systemic therapy (NAST) of early breast cancer (EBC) has been recognized as a good prognostic factor in the treatment of breast cancer because of its significant correlation with long-term disease outcome. Based on this correlation, pCR has been accepted by health authorities (FDA, EMA) as a surrogate endpoint in clinical trials for accelerated drug approval. Moreover, in recent years, we have observed a tendency to treat pCR in routine clinical practice as a primary therapeutic target rather than just one of the pieces of information obtained from clinical trials. These trends in routine clinical practice are the result of recommendations in treatment guidelines, such as the ESMO recommendation "…to deliver all planned (neoadjuvant) treatment without unnecessary breaks, i.e. without dividing it into preoperative and postoperative periods, irrespective of the magnitude of tumor response", because "…this will increase the probability of achieving pCR, which is a proven factor for a good prognosis…". We hypothesize that the above recommendations and trends in routine clinical practice are the consequences of misunderstanding regarding the concept of pCR, which has led to a shift in its importance from a prognostic factor to a desired treatment outcome. The origin of this misunderstanding could be a strong subconscious incentive to achieve pCR, as patients who achieved pCR after NAST had a better long-term outcome compared with those who did not. In this paper, we attempt to prove our hypothesis. We performed a comprehensive analysis of the therapeutic effects of NAST and adjuvant systemic therapy (AST) in EBC to determine whether pCR, as a phenomenon that can only be achieved at NAST, improves prognosis per se. We used published papers as a source of data, which had a decisive influence on the formation of the modern attitude towards EBC therapy. We were unable to find any evidence supporting the use of pCR as a desired therapeutic goal because NAST (reinforced by pCR) was never demonstrated to be superior to AST in any context.

Long-term outcomes of dual vs single HER2-directed neoadjuvant therapy in NSABP B-41

BACKGROUND

The primary aim of this randomized neoadjuvant trial in operable, HER2-positive breast cancer, was to determine the efficacy on pathologic complete response (pCR) of substituting lapatinib (L) for trastuzumab (T) or adding L to T, in combination with weekly paclitaxel (WP) following AC. Results on pCR were previously reported. Here, we report data on planned secondary endpoints, recurrence-free interval (RFI) post-surgery, and overall survival (OS).

METHODS

All patients received standard AC q3 weeks × 4 cycles followed by WP (80 mg/m2) on days 1, 8, and 15, q28 days × 4 cycles. Concurrently with WP, patients received either T (4 mg/kg load, then 2 mg/kg) weekly until surgery, L (1250 mg) daily until surgery, or weekly T plus L (750 mg) daily until surgery. Following surgery, all patients received T to complete 52 weeks of HER2-targeted therapy. 522 of 529 randomized patients had follow-up. Median follow-up was 5.1 years.

RESULTS

RFI at 4.5 years was 87.2%, 79.4% (p = 0.34; HR = 1.37; 95% CI 0.80, 2.34), and 89.4% (p = 0.37; HR = 0.70; 0.37, 1.32) for arms T, L, and TL, respectively. The corresponding five-year OS was 94.8%, 89.1% (p = 0.34; HR = 1.46; 0.68, 3.11), and 95.8% (p = 0.25; HR = 0.58; 0.22, 1.51), respectively. Patients with pCR had a much better prognosis, especially in the ER-negative cohort: RFI (HR = 0.23, p < 0.001) and OS (HR = 0.28, p < 0.001).

CONCLUSIONS

Although pCR, RFI, and OS were numerically better with the dual combination and less with L, the differences were not statistically significant. However, achievement of pCR again correlated with improved outcomes, especially remarkable in the ER-negative subset.

CLINICAL TRIALS REGISTRATION

NCT00486668.

Molecular subtypes as a prognostic breast cancer factor in women users of the São Paulo public health system, Brazil

OBJECTIVE

This study aimed to analyze the prognosis of women with breast cancer by molecular subtypes, sociodemographic variables, and clinical and treatment characteristics.

METHODS

This hospital-based retrospective cohort study analyzed 1,654 women over 18 years of age diagnosed with invasive breast cancer from 2000 to 2018. Data were extracted from Brazil's Oncocenter Foundation of São Paulo. The variables analyzed were age, histology, molecular subtypes, clinical staging, treatment type, and diagnosis-to-treatment time. Cox regression analysis was applied to estimate death risk.

RESULTS

Women with HER-2-positive (nonluminal) and triple-negative molecular subtypes were more than twice more likely to be at risk of death, with adjusted hazard ratio - HRadj=2.30 (95% confidence interval - 95%CI 1.34-3.94) and HRadj=2.51 (95%CI 1.61-3.92), respectively. A delayed treatment associated with an advanced clinical stage at diagnosis increased fourfold the risk of death (HRadj=4.20 (95%CI 2.36-7.49).

CONCLUSION

In summary, besides that interaction between advanced clinical stage and longer time between diagnosis and treatment, HER-2-positive (nonluminal) and triple-negative phenotypes were associated with a worse prognosis. Therefore, actions to reduce barriers in diagnosis and treatment can provide better outcome, even in aggressive phenotypes.

Identification of genetic and immune signatures for the recurrence of HER2-positive breast cancer after trastuzumab-based treatment

PURPOSE

To determine the genetic and immune features associated with the recurrence of human epidermal growth factor receptor2-positive (HER2 +) breast cancer (BC) after trastuzumab-based treatment.

METHODS

A retrospective cohort study of 48 patients who received trastuzumab-based treatment was divided into recurrent and non-recurrent groups according to clinical follow-up. Baseline samples from all 48 patients were analyzed for genetic variation, HLA allele type, gene expression, and immune features, which were linked to HER2 + BC recurrence. Statistics included logistic regression models, Kaplan-Meier plots, and Univariate Cox proportional hazards models.

RESULTS

Compared with the non-recurrent group, the extracellular matrix-related pathway and 3 Hallmark gene sets were enriched in the recurrent group. The infiltration levels of immature B cells and activated B cells were significantly increased in the non-recurrent group, which correlated remarkably with improved overall survival (OS) in two other published gene expression datasets, including TCGA and METABRIC. In the TCGA cohort (n = 275), activated B cells (HR 0.23, 95%CI 0.13-0.43, p < 0.0001), and immature B cells (HR 0.26, 95%CI 0.12-0.59, p < 0.0001). In the METABRIC cohort (n = 236), activated B cells (HR 0.60, 95%CI 0.43-0.83, p = 0.002), and immature B cells (HR 0.65, 95%CI 0.47-0.91, p = 0.011). Cox regression suggested that immature B cells and activated B cells were protective factors for outcome OS.

CONCLUSIONS

Aberrant activation of multiple pathways and low baseline tumor-infiltrating B cells are related to HER2 + BC trastuzumab-based recurrence, which primarily affects the antitumor activity of trastuzumab.

Prognostic and Predictive Value of Immune-Related Gene Expression Signatures vs Tumor-Infiltrating Lymphocytes in Early-Stage ERBB2/HER2-Positive Breast Cancer: A Correlative Analysis of the CALGB 40601 and PAMELA Trials

Importance

Both tumor-infiltrating lymphocytes (TILs) assessment and immune-related gene expression signatures by RNA profiling predict higher pathologic complete response (pCR) and improved event-free survival (EFS) in patients with early-stage ERBB2/HER2-positive breast cancer. However, whether these 2 measures of immune activation provide similar or additive prognostic value is not known.

Objective

To examine the prognostic ability of TILs and immune-related gene expression signatures, alone and in combination, to predict pCR and EFS in patients with early-stage ERBB2/HER2-positive breast cancer treated in 2 clinical trials.

Design, Setting, and Participants

In this prognostic study, a correlative analysis was performed on the Cancer and Leukemia Group B (CALGB) 40601 trial and the PAMELA trial. In the CALGB 40601 trial, 305 patients were randomly assigned to weekly paclitaxel with trastuzumab, lapatinib, or both for 16 weeks. The primary end point was pCR, with a secondary end point of EFS. In the PAMELA trial, 151 patients received neoadjuvant treatment with trastuzumab and lapatinib for 18 weeks. The primary end point was the ability of the HER2-enriched subtype to predict pCR. The studies were conducted from October 2013 to November 2015 (PAMELA) and from December 2008 to February 2012 (CALGB 40601). Data analyses were performed from June 1, 2020, to January 1, 2022.

Main Outcomes and Measures

Immune-related gene expression profiling by RNA sequencing and TILs were assessed on 230 CALGB 40601 trial pretreatment tumors and 138 PAMELA trial pretreatment tumors. The association of these biomarkers with pCR (CALGB 40601 and PAMELA) and EFS (CALGB 40601) was studied by logistic regression and Cox analyses.

Results

The median age of the patients was 50 years (IQR, 42-50 years), and 305 (100%) were women. Of 202 immune signatures tested, 166 (82.2%) were significantly correlated with TILs. In both trials combined, TILs were significantly associated with pCR (odds ratio, 1.01; 95% CI, 1.01-1.02; P = .02). In addition to TILs, 36 immune signatures were significantly associated with higher pCR rates. Seven of these signatures outperformed TILs for predicting pCR, 6 of which were B-cell related. In a multivariable Cox model adjusted for clinicopathologic factors, including PAM50 intrinsic tumor subtype, the immunoglobulin G signature, but not TILs, was independently associated with EFS (immunoglobulin G signature-adjusted hazard ratio, 0.63; 95% CI, 0.42-0.93; P = .02; TIL-adjusted hazard ratio, 1.00; 95% CI, 0.98-1.02; P = .99).

Conclusions and Relevance

Results of this study suggest that multiple B-cell-related signatures were more strongly associated with pCR and EFS than TILs, which largely represent T cells. When both TILs and gene expression are available, the prognostic value of immune-related signatures appears to be superior.

Emerging Targeted Therapies for HER2-Positive Breast Cancer

Breast cancer is the most common cancer in women and the leading cause of death. HER2 overexpression is found in approximately 20% of breast cancers and is associated with a poor prognosis and a shorter overall survival. Tratuzumab, a monoclonal antibody directed against the HER2 receptor, is the standard of care treatment. However, a third of the patients do not respond to therapy. Given the high rate of resistance, other HER2-targeted strategies have been developed, including monoclonal antibodies such as pertuzumab and margetuximab, trastuzumab-based antibody drug conjugates such as trastuzumab-emtansine (T-DM1) and trastuzumab-deruxtecan (T-DXd), and tyrosine kinase inhibitors like lapatinib and tucatinib, among others. Moreover, T-DXd has proven to be of use in the HER2-low subtype, which suggests that other HER2-targeted therapies could be successful in this recently defined new breast cancer subclassification. When patients progress to multiple strategies, there are several HER2-targeted therapies available; however, treatment options are limited, and the potential combination with other drugs, immune checkpoint inhibitors, CAR-T cells, CAR-NK, CAR-M, and vaccines is an interesting and appealing field that is still in development. In this review, we will discuss the highlights and pitfalls of the different HER2-targeted therapies and potential combinations to overcome metastatic disease and resistance to therapy.

Six-Year Survival Outcomes for Patients with HER2-Positive Early Breast Cancer Treated with CT-P6 or Reference Trastuzumab: Observational Follow-Up Study of a Phase 3 Randomised Controlled Trial

BACKGROUND

The Phase 3 CT-P6 3.2 study demonstrated equivalent efficacy and comparable safety between CT-P6 and reference trastuzumab in patients with human epidermal growth factor receptor-2 (HER2)-positive early breast cancer after up to 3 years' follow-up.

OBJECTIVE

To investigate long-term survival with CT-P6 and reference trastuzumab.

METHODS

In the CT-P6 3.2 study, patients with HER2-positive early breast cancer were randomised to neoadjuvant chemotherapy with CT-P6 or reference trastuzumab, surgery, and adjuvant CT-P6 or reference trastuzumab before a 3-year post-treatment follow-up. Patients who completed the study could enter a 3-year extension (CT-P6 4.2 study). Data were collected every 6 months to assess overall survival (OS), disease-free survival (DFS), and progression-free survival (PFS).

RESULTS

Of 549 patients enrolled in the CT-P6 3.2 study, 216 (39.3%) patients continued in the CT-P6 4.2 study (CT-P6, 107; reference trastuzumab, 109) (intention-to-treat extension set). Median follow-up was 76.4 months for both groups. Medians were not reached for time-to-event parameters; estimated hazard ratios (95% confidence intervals) for CT-P6 versus reference trastuzumab were 0.59 (0.17-2.02) for OS, 1.07 (0.50-2.32) for DFS, and 1.08 (0.50-2.34) for PFS. Corresponding 6-year survival rates in the CT-P6 and reference trastuzumab groups, respectively, were 0.96 (0.90-0.99) and 0.94 (0.87-0.97), 0.87 (0.78-0.92) and 0.89 (0.81-0.94), and 0.87 (0.78-0.92) and 0.89 (0.82-0.94).

CONCLUSIONS

Data from this extended follow-up of the CT-P6 3.2 study demonstrate the comparable long-term efficacy of CT-P6 and reference trastuzumab up to 6 years.

EUDRACT NUMBER

2019-003518-15 (retrospectively registered 10 March 2020).

Ten-year survival of neoadjuvant dual HER2 blockade in patients with HER2-positive breast cancer

BACKGROUND

Dual anti-HER2-targeted therapy in breast cancer (BC) significantly increased the rate of pathological complete response (pCR) compared to single blockade when added to chemotherapy. However, limited data exist on the long-term impact on survival of the additional increase in pCR.

METHODS

Neoadjuvant lapatinib and/or trastuzumab treatment optimisation (NCT00553358) is an international, randomised, open-label, phase III study investigating the addition of lapatinib to chemotherapy plus trastuzumab in HER2-positive early BC. Ten-year event-free survival (EFS), overall survival (OS) and safety were assessed on intention-to-treat population. The association between pCR and EFS or OS was investigated in landmark population.

RESULTS

A total of 455 patients were randomised to receive lapatinib (154), trastuzumab (149) or the combination (152). Ten-year EFS estimates were 63% (95% confidence interval [CI], 54%-71%) in the lapatinib group, 64% (95% CI, 55%-72%) in the trastuzumab group and 67% (95% CI, 58%-74%) in the combination group. Ten-year OS rates were 76% (95% CI, 67%-83%), 75% (95% CI, 66%-82%) and 80% (95% CI, 73%-86%) in the lapatinib, trastuzumab and combination groups, respectively. Women who achieved a pCR had improved EFS (hazard ratio 0.48, 95% CI, 0.31-0.73) and OS (hazard ratio 0.37, 95% CI, 0.20-0.63) compared with those who did not. The numerical difference in survival according to pCR status was greater in women treated with the combination and those with hormone-receptor-negative tumours. There were no new or long-term safety concerns.

CONCLUSIONS

Patients with HER2-positive BC showed a durable survival benefit of neoadjuvant anti-HER2, irrespective of treatment arm. Patients who achieve pCR have significantly better outcomes than patients without pCR.

Optimizing treatment for HER2-positive HR-positive breast cancer

Triple-positive breast tumors overexpress human epidermal growth factor receptor 2 (HER2) and are positive for hormone receptor (HR) expression. Data from real-life and clinical trials show that estrogen receptor (ER) expression affects the response to combinations of anti-HER2 and associated systemic therapies. Despite triple-positive tumors having decreased response rates compared to HR-negative/HER2-positive breast cancers, optimizing anti-HER2 treatment with dual anti-HER2 blockade remains important for optimal disease control. Preclinical data on the cross-talk between ER and growth factor receptor pathways show the efficacy of combinations of endocrine therapy and anti-HER2 drugs, which is confirmed in the clinic. Molecular dissection of triple-positive breast cancer might provide the rational for additional therapeutic strategies and the identification of promising biomarkers. This review summarizes data on systemic treatment efficacy from major clinical trials and perspectives for future clinical research in triple-positive breast cancer.