Identification of prognostic different subgroups in triple negative breast cancer by Her2-neu protein expression

Analysis of clinical features, genomic landscapes and survival outcomes in HER2-low breast cancer

BACKGROUND

Novel human epidermal growth factor receptor 2 (HER2)-directed antibody-drug conjugates prompt the identification of the HER2-low subtype. However, the biological significance of HER2-low expression in breast cancer is unclear.

METHODS

Clinical and genomic data of 579 metastatic breast cancer patients were reviewed from our next-generation sequencing (NGS) database and genomic analysis of early breast cancer patients from TCGA was also analyzed.

FINDINGS

First, the clinicopathological characteristics of HER2-low patients were profoundly influenced by HR status and no difference of prognosis was observed between HER2-low and HER2-zero patients when paired by HR status, but notably HER2-low patients showed similar metastatic patterns to HER2-positive patients in the HR-positive (HR+ ) subgroup, with more brain and initial lung metastases and more cases of de novo stage IV breast cancer than HER2-zero patients. Second, among patients with primary HER2-low or HER2-zero tumors, the discordance of HER2 status between primary and metastatic tumors was significant, with 48.4% of patients with HER2-zero primary tumors exhibiting HER2-low phenotype in metastatic tumors in the HR+ subgroup. Third, within HR+ and HR-negative subtypes, HER2-low and HER2-zero tumors showed no substantial differences in mutation alterations and copy number variations. Forth, germline BRCA2 mutations were observed only in HER2-low patients in our NGS database, especially in HR+ HER2-low tumors. Finally, three molecular subtypes based on genomic alterations in HER2-low breast cancer were identified, which provided novel insights into heterogeneity in HER2-low breast cancer.

CONCLUSIONS

After correcting for HR expression, only marginal differences in clinical and molecular phenotypes were determined between HER2-low and HER2-zero breast cancer. Therefore, HER2-low breast cancer is insufficient to be defined as a distinct molecular entity, but rather a heterogenous disease.

The Survival Outcomes of T1aN0M0 Triple-Negative Breast Cancer With Adjuvant Chemotherapy

Purpose: Triple-negative breast cancer (TNBC) is a subtype with distinct heterogeneity, high invasiveness, and poorer prognosis. There is a controversy about adjuvant chemotherapy (ACT) at the T1aN0M0 stage. This study was carried out to assess the survival benefit of ACT for these patients.

Methods: We identified 1,099 patients with T1aN0M0 TNBC who were diagnosed between 2010 and 2016 from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariable analyses were conducted to determine factors related to survival. One-to-one (1:1) propensity score matching (PSM) was applied to construct a matched sample consisting of pairs of ACT and non-ACT subjects. Breast cancer–specific survival (BCSS) and overall survival (OS) of the two groups were evaluated by Kaplan–Meier plots and Cox proportional hazard regression models. Stratified analysis according to different variables was also performed.

Results: No obvious differences in demographic or clinical characteristics were found between patients who had ACT and those without ACT therapy in terms of race, marital status, laterality, or radiation therapy. A higher proportion of patients who were older, had a higher histological grade tumor, and who received breast-conserving surgery had adjuvant chemotherapy. The ACT group did not exhibit better survival in BCSS or OS before PSM. After PSM, the ACT and non-ACT groups consisted of 255 patients, respectively, and Kaplan–Meier curves and multivariate analysis both indicate that adjuvant chemotherapy was not associated with better survival in terms of BCSS or OS. Furthermore, we did not observe any survival advantage in any subgroup irrespective of age, race, marital status, histological grade, surgery type, or radiotherapy status.

Conclusions: The study results indicate that there is no strong association between ACT and better survival in T1aN0M0 TNBC. It implies that the chemotherapy decision should be made cautiously and further research into therapeutic strategies are needed in T1aN0M0 TNBC patients.

Is vimentin a potential prognostic factor for patients with triple-negative breast cancer?

OBJECTIVE

To evaluate the prognostic potential of vimentin, p53, EGFR, CK5/6, CK 14, and CK 17 in patients with triple-negative breast cancer (TNBC).

MATERIAL AND METHODS

Tumor specimens of 60 patients with histologically confirmed TNBC were retrospectively analyzed. Formalin-fixed paraffin-embedded blocks of the tumor tissue were used to prepare tissue microarrays (TMAs). After immune-histochemical staining, protein expression of vimentin, p53, EGFR, CK5/6, CK 14, and CK 17 was determined and the immunoreactive score (IRS) was calculated. The protein expression was correlated to overall (OS) and disease-free survival (DFS).

RESULTS

Ninety percent of patients suffered from an invasive ductal carcinoma T1 or T2, 66.7% were N0, and 70% had a G3 tumor with Ki67 of > 14%. Vimentin expression was found in 28/60 patients (46.7%), p53 expression in 30/60 patients (50%), and EGFR expression in 3/60 patients (5%). CK5/6, CK14, and CK17 expression was found in 60.0%, 63.3%, and 66.7%, respectively. Vimentin expression vs no expression was associated with significantly higher mean Ki67 values (52.5% vs. 31.1%; p = 0.0013) and significantly higher p53 expression (67.9% vs. 34.4%; p = 0.0097). No significant association between vimentin expression and OS (p = 0.7710) or DFS (p = 0.5558) was found during a mean follow-up of 92 months.

CONCLUSION

None of the six proteins proved to be suitable prognostic factors for OS and DSF in patients with TNBC.

Prognostic Value of Ki-67 in Patients With Resected Triple-Negative Breast Cancer: A Meta-Analysis

Background: Ki-67 is a widely used marker of tumor proliferation, but the prognostic value of ki-67 in triple-negative breast cancer (TNBC) has not been comprehensively reviewed. This meta-analysis was conducted to evaluate the association between ki-67 expression and survival of patients with resected TNBC.

Materials and Methods: Relevant studies, evaluating the prognostic impact of pretreatment ki-67 in resected TNBC patients, were identified from PubMed, Embase, Web of Science, China National Knowledge Infrastructure, and Cochrane Library until March 14, 2019. Hazard ratios (HRs) with 95% confidence intervals (CI) were calculated as effect values for disease-free survival (DFS) and overall survival (OS).

Results: In present meta-analysis, 35 studies with 7,716 enrolled patients were eligible for inclusion. Pooled results showed that a high ki-67 expression was significantly associated with poor DFS (HR = 1.73, 95% CI: 1.45–2.07, p < 0.001) and poor OS (HR = 1.65, 95% CI: 1.27–2.14, p < 0.001) in resected TNBC. In the subgroup analysis, when a cutoff of Ki-67 staining ≥40% was applied, the pooled HR for DFS and OS was 2.30 (95% CI 1.54–3.44, p < 0.001) and 2.95 (95% CI 1.67–5.19, p < 0.001), respectively.

Conclusion: A high Ki-67 expression is a poor prognostic factor of resected TNBC. The cut-off of ki-67 ≥40% is associated with a greater risk of recurrence and death compared with lower expression rates, despite the Ki-67 threshold with the greatest prognostic significance is as yet unknown.

Potential clinically useful prognostic biomarkers in triple-negative breast cancer: preliminary results of a retrospective analysis

Background

Triple-negative breast cancer (TNBC) has a poor prognosis, even in its early stages. In the absence of postoperative targeted treatments, intensive adjuvant chemotherapy regimens are proposed. For those favorable histologies, such as apocrine and adenoid cystic carcinoma, which frequently belong to TNBC, aggressive treatments are unnecessary.

Patients and methods

We retrospectively analyzed 631 cases of breast cancer, primary operated curatively, and followed up at our institution for at least 36 months to identify the bio-markers assessable by immunohistochemistry, to be proposed as prognostic score for tailoring adjuvant treatment to TNBC patients.

Results

The triple-negative phenotype was found in 85 patients (13.5%). Over a mean followup of 55.7 months, relapses occurred in 106 patients (16.8%), of which 18 (2.8%) were TNBC. Recurrence was directly correlated with Ki67 and cytokeratin 5/6 (CK5/6) immunoreactivity in all breast cancer patients (P=0.005), but only marginally with CK5/6 and epithelial cadherin (E-cad) expression in TNBC patients (P=0.07). Mean event-free survival (EFS) in TNBC patients was 85.52 months compared with 100.4 months in non-TNBC patients (P=0.228). The EFS of CK5/6-negative triple-negative patients was 68.84 months compared with 98.84 months in those who were CK5/6 positive (HR =5.08; P=0.038). EFS differed among patients identified as double-positive for E-cad and CK5/6 (83.87 months), those expressing E-cad or CK5/6 (64.23 months), and those negative for both biomarkers (39.64 months).

Conclusion

These preliminary results suggest that CK5/6 and E-cad are possible core biomarkers for a cost-effective prognostic evaluation of primary operable TNBC patients.

The CD4/CD8 ratio of tumor-infiltrating lymphocytes at the tumor-host interface has prognostic value in triple-negative breast cancer

Compelling evidence has demonstrated the prognostic value of tumor-infiltrating lymphocytes (TILs), especially in triple-negative breast cancer (TNBC). However, only a limited number of studies to investigate the importance of the subsets of T cells in TILs have been carried out, less so the significance of the location of these TILs. In this study, we explored in a cohort of 42 consecutive TNBC cases the prognostic significance of TIL subsets at the tumor-host interface (within 1 high-power field [0.5 mm] of the invasive front) and compared them with TILs within the intratumoral stroma. Given the reported importance of TILs in HER2-overexpressing breast cancer, a subset of such tumors was also included for comparison. The range was wide in both locations; nevertheless, the mean CD4⁺ and CD8⁺ T cell count was significantly higher at the tumor-host interface than that found within the intratumoral stroma (both P<.0001). The number of CD4⁺ or CD8⁺ T cells at either location was not significantly associated with distant relapse-free or overall survival. However, the CD4/CD8 ratio at the tumor-host interface was significantly associated with both relapse-free survival (hazard ratio 0.2, P=.002) and overall survival (hazard ratio 0.13, P=.002), whereas this association was not seen for the CD4/CD8 ratio within the intratumoral stroma. As expected, both tumor size and nodal status were significantly associated with survival outcomes. The findings further support the contention that TILs, as markers of regional immune escape, are of prognostic importance in TNBC progression and that the CD4/CD8 ratio of TILs at the tumor-host interface plays a distinctive role, thus appearing to be of clinical relevance.

Prognostic Value of E-Cadherin and β-Catenin in Triple-Negative Breast Cancer

OBJECTIVES

To analyze the expression of E-cadherin and β-catenin in triple-negative breast cancer (TNBC) to assess their prognostic significance.

METHODS

The expression of E-cadherin and β-catenin was examined semiquantitatively and correlated with other pathologic factors and survival outcomes.

RESULTS

Of 72 consecutive TNBCs, 56% showed reduced membranous expression of E-cadherin or β-catenin, with a strong correlation to each other. Of the clinicopathologic factors analyzed, tumor size and nodal status were significantly associated with overall survival and disease-specific survival, while the latter remained an independent factor by multivariate analysis. Reduced E-cadherin and β-catenin were both significantly associated with a poor overall survival and disease-specific survival by univariate and multivariate analyses.

CONCLUSIONS

E-cadherin and β-catenin expression provides discriminative prognostic power independent of conventional pathologic factors, thus further reinforcing the important role of cell adhesion molecules in the process of tumor metastasis, especially in TNBC.

Loss of Anti-HER-3 CD4+ T-Helper Type 1 Immunity Occurs in Breast Tumorigenesis and is Negatively Associated with Outcomes

BACKGROUND

We previously demonstrated a progressive loss of the anti-human epidermal growth factor receptor 2 (HER2) CD4+ T-helper type 1 (Th1) response during HER2^pos breast tumorigenesis. This loss is associated with residual disease following neoadjuvant therapy and increased risk of recurrence. In this study, we assessed the fate of anti-HER3 Th1 immunity during breast tumorigenesis.

METHODS

Peripheral blood from 131 subjects, including healthy donors (HDs), patients with benign breast disease (BD), ductal carcinoma in situ (DCIS) and invasive breast cancer (IBC), was collected. Interferon (IFN)-γ^pos immune responses to four HER3-derived major histocompatibility complex (MHC) class II promiscuous peptides were tested via enzyme-linked immunosorbent (ELISPOT) assays, and three immune response parameters were compared: anti-HER3 (i) responsivity, or proportion of subjects responding to at least one peptide; (ii) repertoire, or number of responding peptides; and (iii) cumulative response, or summed peptide response.

RESULTS

A significant decline in anti-HER3 Th1 response was observed going from HDs to IBC patients; patients with triple-negative breast cancer (TNBC) demonstrated the lowest responses. HDs had significantly higher Th1 responses versus estrogen receptor (ER)^pos IBC and TNBC patients across all three immune parameters; HER2^pos IBC patients displayed responses similar to HDs and BDs. Patients with recurrent breast cancer and residual disease following neoadjuvant therapy demonstrated significantly lower anti-HER3 Th1 immunity compared with patients without recurrence or with a pathologic complete response to neoadjuvant therapy.

CONCLUSIONS

Anti-HER3 CD4+ Th1 responses decline during breast tumorigenesis, particularly in TNBC. Attempts to immunologically restore depressed responses in vulnerable subgroups may help mitigate recurrence.

Her2-neu score as a prognostic factor for outcome in patients with triple-negative breast cancer

PURPOSE

Triple-negative breast cancer (TNBC) is characterized by a strong heterogeneity with regard to tumour biology as well as in the clinical course of the disease. This study aimed to analyse whether there are any prognostic factors enabling prediction of the clinical outcome in patients with TNBC. Particularly, the impact of Her2-neu score 0 versus Her2-neu score 1 and 2 on survival was investigated.

MATERIALS AND METHODS

We retrospectively studied a cohort of 1013 patients with TNBC, diagnosed at seven hospitals between May 2002 and February 2015. We studied the impact of Her2-neu scores (0 vs. 1 or 2 with negative FISH) on disease-free survival (DFS) and overall survival (OS).

RESULTS

1013 patients were included in this study. 447 (44.13 %) of them had a T2-4 tumour. A total of 314 (31.00 %) were nodal-positive and 714 (70.48 %) had high-grade tumours. The Her2-neu score of all participating patients was determined. 588 (58.05 %) of them had a Her2-neu score 0, and 425 (41.95 %) had a score of 1 or 2. This study shows that TNBC patients with a Her2-neu score 0 had a significantly poorer outcome regarding DFS (p = 0.0001) and OS (p = 0.0051) compared to a score of 1 or 2. In contrast, grading did not seem to have any prognostic value for women with TNBC.

CONCLUSION

The Her2-neu score 0 might be considered as an innovative prognostic factor for patients with TNBC indicating poor clinical outcome.

An overview of triple-negative breast cancer

PURPOSE

Triple-negative breast cancer (TNBC) is a heterogeneous group of tumors comprising various breast cancers simply defined by the absence of estrogen receptor, progesterone receptor and overexpression of human epidermal growth factor receptor 2 gene. In this review, we discuss the epidemiology, risk factors, clinical characteristics and prognostic variables of TNBC, and present the summary of recommended treatment strategies and all other available treatment options.

METHODS

We performed a systematic literature search using Medline and selected those articles which seemed relevant for this review. In addition, the ClinicalTrials.gov was also scanned for ongoing trials.

RESULTS

TNBC accounts for 10-20 % of all invasive breast cancers and has been found to be associated with African-American race, younger age, higher grade and mitotic index, and more advanced stage at diagnosis. Locoregional treatment is similar to other invasive breast cancer subtypes and involves surgery-mastectomy with or without adjuvant radiotherapy or breast conservation followed by adjuvant radiotherapy. Due to lack of drug-targetable receptors, chemotherapy is the only recommended systemic treatment to improve disease outcome. TNBC is sensitive to chemotherapy as demonstrated by high pathological complete response rates achieved after neoadjuvant chemotherapy, and this approach also allows for breast-conserving surgery. The peak risk of relapse is at 3 years after surgery, thereafter recurrence risk rapidly decreases. Survival after metastatic relapse is shorter as compared to other breast cancer subtypes, treatment options are few and response rates are poor and lack durability. Important molecular characteristics have now been identified that can subdivide this group of breast cancers further and can provide alternative systemic therapies.

CONCLUSIONS

To improve therapeutic outcome of TNBC, reliable predictive biomarkers and newer drugs against the known molecular pathways are required.