Neoadjuvant treatment of HER2 and hormone-receptor positive breast cancer - moving beyond pathological complete response

The Role of Ultrasound Features in Predicting the Breast Cancer Response to Neoadjuvant Chemotherapy

Background Neoadjuvant chemotherapy (NACT) has become the standard of care for locally advanced breast cancer. This study investigates whether baseline ultrasound features can predict complete pathological response (pCR) after NACT. Methods This retrospective study was approved by the Institutional Review Board of King Abdulaziz University Hospital, Jeddah, Saudi Arabia, with a waiver of informed consent. Records of female patients aged over 18 years with locally advanced breast cancer treated with NACT from 2018 to 2020 were reviewed. Baseline ultrasound parameters were assessed, including posterior effect, echo pattern, margin, and maximum lesion diameter. Tumor grade and immunophenotype were documented from the core biopsy. pCR was defined as the absence of invasive residual disease in the breast and axilla. Univariate and multivariate analyses assessed the association between ultrasound features and pathological response. Results A total of 110 breast cancer cases were analyzed: 36 (32.7%) were estrogen receptor (ER)-positive/human epidermal growth factor 2 (HER-2) negative, 49 (44.5%) were HER-2 positive, and 25 (22.7%) were triple-negative (TN). A pCR was achieved in 20 (18%) of cancers. Lesion diameter was significantly different between pCR and non-pCR groups, 28.5 ± 12 mm versus 39 ± 18 mm, respectively, with an area under the curve (AUC) of 0.7, a confidence interval (CI) of 0.55-0.81, and a p-value of 0.01. No significant association was observed between ultrasound features, tumor grade, and immunophenotype with pCR. Conclusion Ultrasound features could not predict pCR. A smaller tumor diameter was the only significant factor associated with pCR. Further prospective studies combining imaging features from different modalities are needed to explore the potential of varying imaging features in predicting post-NACT pathological response more comprehensively.

Current trends in the treatment of HR+/HER2+ breast cancer

Treatment for HR+/HER2+ patients has been debated, as some tumors within this luminal HER2+ subtype behave like luminal A cancers, whereas others behave like non-luminal HER2+ breast cancers. Recent research and clinical trials have revealed that a combination of hormone and targeted anti-HER2 approaches without chemotherapy provides long-term disease control for at least some HR+/HER2+ patients. Novel anti-HER2 therapies, including neratinib and trastuzumab emtansine, and new agents that are effective in HR+ cancers, including the next generation of oral selective estrogen receptor downregulators/degraders and CDK4/6 inhibitors such as palbociclib, are now being evaluated in combination. This review discusses current trials and results from previous studies that will provide the basis for current recommendations on how to treat newly diagnosed patients with HR+/HER2+ disease.

Current Landscape of Breast Cancer Imaging and Potential Quantitative Imaging Markers of Response in ER-Positive Breast Cancers Treated with Neoadjuvant Therapy

In recent years, neoadjuvant treatment trials have shown that breast cancer subtypes identified on the basis of genomic and/or molecular signatures exhibit different response rates and recurrence outcomes, with the implication that subtype-specific treatment approaches are needed. Estrogen receptor-positive (ER+) breast cancers present a unique set of challenges for determining optimal neoadjuvant treatment approaches. There is increased recognition that not all ER+ breast cancers benefit from chemotherapy, and that there may be a subset of ER+ breast cancers that can be treated effectively using endocrine therapies alone. With this uncertainty, there is a need to improve the assessment and to optimize the treatment of ER+ breast cancers. While pathology-based markers offer a snapshot of tumor response to neoadjuvant therapy, non-invasive imaging of the ER disease in response to treatment would provide broader insights into tumor heterogeneity, ER biology, and the timing of surrogate endpoint measurements. In this review, we provide an overview of the current landscape of breast imaging in neoadjuvant studies and highlight the technological advances in each imaging modality. We then further examine some potential imaging markers for neoadjuvant treatment response in ER+ breast cancers.

Evaluation of the prognostic stage in the 8th edition of the American Joint Committee on Cancer in locally advanced breast cancer: An analysis based on SEER 18 database

BACKGROUND

The new "prognostic stage" in the 8th edition of the American Joint Committee on Cancer (AJCC) incorporated important biologic factors such as estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER2), histologic grade and TNM stage into one system. The objective of this study was to evaluate the "prognostic stage" in locally advanced breast cancer (LABC) based on the Surveillance, Epidemiology, and End Results (SEER) 18 database.

METHODS

10053 LABCs diagnosed between 2010 and 2013 were enrolled. TNM stage was based on AJCC 7th edition. Comparisons of biologic factor proportions among stage changes were performed using Pearson's chi-square test. Breast cancer-specific survival (BCSS) and overall survival (OS) were estimated using the Kaplan-Meier method and log rank testing with pairwise comparisons between different stages was conducted. Cox models were fitted to assess the independent prognostic factors.

RESULTS

The prognostic stage grouped LABC into six stages: IB-IIIC among which IB-IIIA had a relatively better survival. It reassigned 74% LABCs to a different tumor stage. 60.4% cases in grade III and 68.3% cases with triple negative breast cancer were upstaged while 57.1% cases with ER/PR dual positivity were down staged. It was an independent prognostic factor of LABC. There were statistically significant survival differences among stage IB-IIIA, IIIB and IIIC. Among each TNM stage, there were statistically significant survival differences among stage changes.

CONCLUSIONS

The prognostic stage provided accurate prognostic information for LABC compared with anatomic TNM stage. It will lead to accuracy in prognosis prediction and optimal treatment selection, and therefore, better outcomes.

[Evaluation of breast HER2+ cancer pathologic response after a taxan plus trastuzumab-based chemotherapy]

OBJECTIVES

In our study, we aimed to assess the pathologic complete response after neo-additive chemotherapy that contains a taxan associated to trastuzumab for patients treated from breast cancer at the institute Jean-Godinot between 2012 and 2014, and to evaluate factors associated to this pathologic complete response.

METHODS

Retrospective study with clinical, anatomopathologic and radiologic parameters analysis before and after new adjuvant chemotherapy. The statistical analysis was done on logiciel XL-STAT, the Mann-Whitney-Wilcoxon for quantitative variables and Fisher exact tests for qualitative variables, the Spearman rang test.

RESULTS

The rate of pathologic complete response is 38.8%. The prognostic factor associated to pathologic complete response is a Ki-67>44%.

CONCLUSION

The pathologic complete response rate corresponds to international lower rate; because of the lack of several data, we found out only one prognostic factor, Ki-67>44%.

Predictors of pathological complete response to neoadjuvant chemotherapy in stage II and III breast cancer: The impact of chemotherapeutic regimen

In this study, we sought to determine the predictors of pathological complete response (pCR) and compare the chemotherapeutic regimens administered to breast cancer patients with and those without pCR. We retrospectively reviewed the data of 879 patients treated at the Alvin J. Siteman Cancer Center between 2006 and 2010, to identify patients who were diagnosed with primary stage II or III breast cancer and received neoadjuvant chemotherapy. Patients who received only neoadjuvant endocrine therapy were considered to be ineligible. Patient, tumor, and treatment characteristics, including type of chemotherapy, were compared between patients who did and those who did not achieve pCR using Chi-square or Fishers exact tests and multivariate logistic regression analysis. Two-sided P-values of <0.05 were considered significant. Of the 333 patients who met the inclusion criteria, 61 (18.3%) had documented pCR. Compared with patients not achieving pCR, a greater proportion of patients with pCR had stage II disease (80.3 vs. 68%, P=0.057), had poorly differentiated (grade 3) tumors (82 vs. 59.2%, P<0.001), had negative lymph node involvement (41 vs. 34%, P=0.0004) and had tumors that were HER2-amplified (41 vs. 23.5%, P=0.0054). A greater proportion of patients with pCR received taxane-based chemotherapy (23 vs. 12.5%, P=0.016) or trastuzumab in conjunction with chemotherapy (41.0 vs. 16.9%, P<0.001). No patients receiving solely anthracycline-based therapy achieved pCR in our study. Our study demonstrated that, for stage II and III breast cancer, lower stage, negative lymph node involvement and HER2 receptor amplification were each associated with pCR. Taxane therapy and the concurrent use of trastuzumab were also associated with a higher likelihood of pCR.