Alterations in Breast Cancer Biomarkers Following Neoadjuvant Therapy

Change in Biomarker Profile After Neoadjuvant Chemotherapy is Prognostic and Common Among Patients with HER2+ Breast Cancer

BACKGROUND

Rates of pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) for breast cancer have improved, especially among human epidermal growth factor 2-positive (HER2+) and triple-negative subtypes. The frequency and significance of biomarker profile change in residual disease are unclear. This study aimed to determine the rate of biomarker profile changes after NAC and the impact on clinical outcomes in a contemporary cohort.

METHODS

Upon institutional review board approval, the study identified 634 consecutive patients treated with NAC between 2010 and 2022 at two academic institutions. The study cohort was focused on patients with residual disease who underwent biomarker profile retesting. Biomarker profile change for each subtype was compared across groups using Fisher-Irwin tests. Cox Proportional Hazards Model and Kaplan-Meier plots were performed to evaluate the association of changed versus unchanged biomarker profile with event-free survival.

RESULTS

Biomarker retesting was performed for 259 (61.4 %) of 422 patients with residual disease. Biomarker profile change occurred in 18.1 % overall and was significantly higher among those with pre-NAC HER2+ disease (32.7 %, 17/52) than among those with HER2-disease (14.5 %, 30/207) (p = 0.004). Conversion of pre-NAC biomarker profiles of HR+HER2- and HR+HER2+ to triple-negative breast cancer (TNBC) post-NAC may be associated with worse event-free survival, hazard ratios of 2.23 (95 % confidence interval [CI], 0.90-5.53; p = 0.08), trending toward significance, and 36.7 (95 % CI, 2.2-610.8; p = 0.01), respectively.

CONCLUSIONS

The results from one of the largest contemporary cohorts demonstrated that biomarker profile change in patients with residual disease after NAC was common. Furthermore, specific biomarker profile change in residual disease may have prognostic value. These findings strengthen the rationale for routine re-testing of biomarkers in residual disease after NAC.

Impact of Neoadjuvant Chemotherapy (NAC) on Biomarker Expression in Breast Cancer

Background and Objectives: This study aimed to explore biomarker change after NAC (neoadjuvant chemotherapy) and to investigate biomarker expression as a prognostic factor in patients with residual disease (RD) after NAC. Materials and Methods: We retrospectively evaluated 104 patients with invasive breast cancer, who underwent NAC and surgery at Pusan National University Hospital from 2015 to July 2022. The expression of the biomarker was assessed, and the overall survival (OS) and disease-free survival (DFS) were investigated. Results: After NAC, 24 patients (23.1%) out of 104 total patients had a pathological complete response (pCR). We found that changes in at least one biomarker were observed in 41 patients (51.2%), among 80 patients with RD. In patients with RD after NAC (n = 80), a subtype change was identified in 20 patients (25.0%). Any kind of change in the HER2 status was present 19 (23.7%) patients. The hormone receptor (HR)+/HER2+ subtype was significantly associated with better disease-free survival (DFS) (HR, 0.13; 95% CI, 0.02-0.99; p = 0.049). No change in p53 was associated with better DFS, and negative-to-positive change in p53 expression after NAC was correlated with worse DFS (p < 0.001). Negative-to-positive change in p53 was an independent, worse DFS factor in the multivariate analysis (HR,18.44; 95% CI, 1.86-182.97; p = 0.013). Conclusions: Biomarker change and subtype change after NAC were not infrequent, which can affect the further treatment strategy after surgery. The expression change of p53 might have a prognostic role. Overall, we suggest that the re-evaluation of biomarkers after NAC can provide a prognostic role and is needed for the best decision to be made on further treatment.

Routine Use of a Standardized Mastectomy Diagram by Surgeons Improves Accuracy and Timeliness of the Final Pathological Report

BACKGROUND

Accurate and timely assessment of pathology specimens is critical for patient care and oncologic management. This study aimed to determine whether a standardized mastectomy diagram would facilitate communication among surgeons and pathologists and improve pathologic processing.

METHODS

A prospective quality improvement study was conducted over a continuous 12-month period. During the first 6 months, usual pathologic processing of mastectomy specimens was performed per standard department protocol. In the second 6 months, a standardized mastectomy diagram was completed at the time of surgery, noting the location and preoperative pathologic diagnosis of all benign and malignant lesions. An analysis of covariance was used to compare the number of breast lesions identified and the number of days between specimen receipt and the date of the final pathology report between each group.

RESULTS

Time from specimen receipt to final pathologic report decreased from a mean (± SE) of 8.3 ± 0.7 days in the usual processing group to 6.1 ± 0.6 days with the use of the standardized mastectomy diagram, for a between-group difference of 2.1 days (95% confidence interval [CI] 0.3-4.0; p = 0.02). The number of lesions identified increased from 1.8 ± 0.2 to 2.6 ± 0.2, for a between-group difference of 0.8 (95% CI 0.1-1.5; p = 0.02).

CONCLUSION

A standardized mastectomy diagram completed at the time of surgery improves the quality of pathologic processing. The diagram, which serves as a mastectomy lesion map, assists lesion localization, enhances accuracy, and reduces time to final pathology report.

Phase II study (KAMELEON) of single-agent T-DM1 in patients with HER2-positive advanced urothelial bladder cancer or pancreatic cancer/cholangiocarcinoma

The antibody-drug conjugate trastuzumab emtansine (T-DM1) is approved for human epidermal growth factor receptor 2 (HER2/ERBB2)-positive breast cancer. We aimed to study tumor HER2 expression and its effects on T-DM1 responses in patients with HER2-positive urothelial bladder cancer (UBC) or pancreatic cancer (PC)/cholangiocarcinoma (CC). In the phase II KAMELEON study (NCT02999672), HER2 status was centrally assessed by immunohistochemistry, with positivity defined as non-focal homogeneous or heterogeneous overexpression of HER2 in ≥30% of stained cells. We also performed exploratory biomarker analyses (e.g., gene-protein assay) on tissue samples collected from study participants and consenting patients who failed screening. Of the 284 patients successfully screened for HER2 status (UBC, n = 69; PC/CC, n = 215), 13 with UBC, four with PC, and three with CC fulfilled eligibility criteria. Due to recruitment difficulty, the sponsor terminated KAMELEON prematurely. Of the five responders in the UBC cohort (overall response rate, 38.5%), HER2 expression was heterogeneous in two and homogeneous in three. The one responder in the PC/CC cohort had PC, and the tumor displayed homogeneous expression. In the biomarker-evaluable population, composed of screen-failed and enrolled patients, 24.3% (9/37), 1.5% (1/66), and 8.2% (4/49) of those with UBC, PC, or CC, respectively, had HER2-positive tumors. In a gene-protein assay combining in situ hybridization with immunohistochemistry, greater HER2 homogeneity was associated with increased ERBB2 amplification ratio. In conclusion, KAMELEON showed that some patients with HER2-positive UBC or PC can respond to T-DM1 and provided insight into the prevalence of HER2 positivity and expression patterns in three non-breast tumor types.

Association of serum reproductive hormones changes after neoadjuvant chemotherapy with hormone receptors expression alterations and survival outcomes in breast cancer

Purpose

This study aimed to determine the effect of neoadjuvant chemotherapy (NAC) on circulating levels of reproductive hormones and evaluate the correlation of hormone changes after NAC with hormone receptors expression alterations and relapse-free survival (RFS) outcomes in breast cancer.

Methods

Information from 181 breast cancer patients who received NAC was retrospectively analyzed. For hormones parameters, the median and interquartile range (IQR) were provided at baseline and the end of NAC then was compared by Wilcoxon signed-rank test. Categorical variables were represented as numbers and percentages and were compared via two-sided chi-square and Fisher's tests. The RFS outcomes were compared between patients according to hormone changes using the log-rank test. Univariate and multivariate survival analyses with hazard ratios (HR) and 95% confidence intervals (95% CI) were carried out using Cox regression.

Results

Sex steroids including estradiol, progesterone, testosterone, and dehydroepiandrosterone sulfate (DHEAS) levels decreased significantly after NAC among both premenopausal and postmenopausal patients (all P < 0.05). Decreased estradiol levels were associated with reduced progesterone receptor (PR) expression (P = 0.030). In multivariate survival analysis, the non-decreased progesterone level was strongly associated with worse RFS (non-decreased vs. decreased, HR = 7.178, 95% CI 2.340–22.019, P = 0.001). Patients with decreased progesterone levels exhibited better 3-year RFS compared with those with non-decreased (87.6% vs. 58.3%, log-rank, P = 0.001).

Conclusion

Multiple reproductive hormone levels were influenced by NAC. The change in estradiol level had a positive connection with PR expression alteration. Furthermore, an inverse association between the change in progesterone level and RFS outcomes was found. These findings may provide a theoretical basis for pre-operative endocrine therapy combined with NAC in breast cancer patients.

Biomarkers Changes after Neoadjuvant Chemotherapy in Breast Cancer: A Seven-Year Single Institution Experience

The adoption of neoadjuvant chemotherapy (NACT) for breast cancer (BC) is increasing. The need to repeat the biomarkers on a residual tumor after NACT is still a matter of debate. We verified estrogen receptors (ER), progesterone receptors (PR), Ki67 and human epidermal growth factor receptor 2 (HER2) status changes impact in a retrospective monocentric series of 265 BCs undergoing NACT. All biomarkers changed with an overall tendency toward a reduced expression. Changes in PR and Ki67 were statistically significant (p = 0.001). Ki67 changed in 114/265 (43.0%) cases, PR in 44/265 (16.6%), ER in 31/265 (11.7%) and HER2 in 26/265 (9.8%). Overall, intrinsic subtype changed in 72/265 (27.2%) cases after NACT, and 10/265 (3.8%) cases switched to a different adjuvant therapy accordingly. Luminal subtypes changed most frequently (66/175; 31.7%) but with less impact on therapy (5/175; 2.8%). Only 3 of 58 triple-negative BCs (5.2%) changed their intrinsic subtype, but all of them switched treatment. No correlation was found between intrinsic subtype changes and clinicopathological features. To conclude, biomarkers changes with prognostic implications occurred in all BC intrinsic subtypes, albeit they impacted therapy mostly in HER2 negative and/or hormone receptors negative BCs. Biomarkers retesting after NACT is important to improve both tailored adjuvant therapies and prognostication of patients.

Breast Cancer Heterogeneity

Breast tumor heterogeneity is a major challenge in the clinical management of breast cancer patients. Both inter-tumor and intra-tumor heterogeneity imply that each breast cancer (BC) could have different prognosis and would benefit from specific therapy. Breast cancer is a dynamic entity, changing during tumor progression and metastatization and this poses fundamental issues to the feasibility of a personalized medicine approach. The most effective therapeutic strategy for patients with recurrent disease should be assessed evaluating biopsies obtained from metastatic sites. Furthermore, the tumor progression and the treatment response should be strictly followed and radiogenomics and liquid biopsy might be valuable tools to assess BC heterogeneity in a non-invasive way.