Neoadjuvant chemotherapy for “Triple Negative” breast cancer: a review of current practice and future outlook

Epigenetic drugs induce the potency of classic chemotherapy, suppress post-treatment re-growth of breast cancer, but preserve the wound healing ability of stem cells

Epigenetic therapy augments neoadjuvant chemotherapy (NACT) in breast cancer and may aid post-surgical wound healing affected by NACT. Our study investigates: (1) The cytotoxicity of classic paclitaxel chemotherapy on triple negative breast cancer (TNBC) independently and in combination with epigenetic drugs. (2) The sustainable inhibition of breast cancer regrowth following paclitaxel and epigenetic therapies. (3) The effects of paclitaxel with and without epigenetic therapy on the post-treatment viability and wound healing potential of adipose stem cells (ASCs). Cytotoxicity assays were performed on TNBC and ASCs. Cells were treated and recovered in drug-free medium. Cell viability was measured via cell counts and MTT assays. W -ound healing was tested with scratch assays. The combination of epigenetic drugs shows increased toxicity against TNBC cells compared to standard chemotherapy alone. Moreover, the combination of paclitaxel with epigenetic treatments causes cancer toxicity that is sustainable to TNBC cells after the drugs' removal with minimal effect on ASCs wound healing ability. The use of epigenetic drugs in addition to standard chemotherapy is cytotoxic to TNBC cells and prevents post-treatment recovery of TNBC while maintaining ASC wound healing ability. This strategy may be useful in maximizing post-surgical wound healing following NACT in TNBC.

SDF-1 expression and tumor-infiltrating lymphocytes identify clinical subtypes of triple-negative breast cancer with different responses to neoadjuvant chemotherapy and survival

Background

In this study, we investigated the prediction and prognostic value of SDF-1 for triple-negative breast cancer (TNBC) patients who underwent neoadjuvant chemotherapy (NAC) following standard radical surgery.

Methods

A total of 303 TNBC patients were included in this study. The NAC regimen was weekly paclitaxel plus carboplatin (PC) for all patients. SDF-1 and CXCR4 expression were measured at baseline and surgery via enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry (IHC), respectively. Correlations between variables and treatment response were studied, and Cox proportional hazards regression analysis was implemented for prognostic evaluation.

Results

Of the 303 patients, 103 (34.0%) experienced pathological complete response (pCR) after completion of NAC. Serum SDF-1 expression before NAC was significantly correlated with the abundance of TILs. A higher pCR rate was more likely to be observed in patients with lower serum SDF-1 levels before NAC (P=0.001, OR=0.997, 95% CI: 0.996-0.999) and higher levels of TILs (P=0.005). In the multivariate survival model for nonpCR patients, serum SDF-1 expression at surgery served as an independent prognostic value for survival (high level, HR=1.980, 95% CI: 1.170-3.350, low level was used as a reference; P=0.011). Additionally, the predictive and prognostic value of serum SDF-1 expression was significant in patients with high abundance of TILs but not in patients with low abundance of TILs.

Conclusions

This study contributes to the clarification of the value of serum SDF-1 to predict pCR and survival for TNBC patients who underwent NAC. This new serum marker, together with TILs, might help identify clinical subtypes of TNBC with different treatment responses and survival and play an important role in tailoring and modifying the NAC strategy for advanced TNBCs in the future.

eEF2 kinase mediated autophagy as a potential therapeutic target for paclitaxel-resistant triple-negative breast cancer

Background

Triple-negative breast cancers (TNBCs) are initially responsive to chemotherapy, but most recurrent TNBCs develop resistance. Autophagy is believed to play dual roles in cancer and might contribute to chemoresistance. In this study, we aimed to investigate the role of autophagy and its regulator, eukaryotic elongation factor 2 kinase (eEF2K), in determining the biological nature of TNBC.

Methods

We used in vitro models of TNBC, namely, paclitaxel-resistant cell lines derived from sensitive cell lines. Various approaches to measuring autophagy flux were applied. We assessed the effects of inhibiting autophagy and silencing eEF2K on cell viability, tumor formation and invasion. We also collected residual tumor samples from 222 breast cancer patients who underwent neoadjuvant chemotherapy and measured eEF2K and LC3 expression levels by immunohistochemistry (IHC). Multivariate survival analysis was used to determine prognostic variables.

Results

Compared to the parental lines, the chemoresistant lines exhibited enhanced starvation-stimulated autophagy and showed significant decreases in cell viability, growth and invasion upon treatment with autophagy inhibitors. eEF2K silencing also resulted in the suppression of autophagic activity and in aggressive biological behavior. In the survival analysis, residual tumor LC3 (P=0.001) and eEF2K (P=0.027) expression levels were independent prognostic factors for patients who underwent neoadjuvant chemotherapy, especially in those with TNBC.

Conclusions

Our study indicated that eEF2K and autophagy play key roles in the maintenance of aggressive tumor behavior and chemoresistance in resistant TNBC. eEF2K silencing may be a novel strategy for the treatment of TNBC.

Predictive and prognostic value of Matrix metalloproteinase (MMP) - 9 in neoadjuvant chemotherapy for triple-negative breast cancer patients

Background

This study aimed to investigate the clinical utility of serum and histological MMP-9 detection during neoadjuvant chemotherapy (NAC) for triple-negative breast cancer (TNBC).

Methods

A total of 303 TNBC patients who underwent weekly paclitaxel plus carboplatin treatments followed by surgical resection were included in this study. Enzyme-linked immunosorbent assay (ELISA) was used to detect the serum level of Matrix metalloproteinase-9 (sMMP-9) at baseline and prior to surgery. Immunohistochemistry was used to detect histological MMP-9 (hMMP-9) expression in patients with residual tumors after NAC. The value of MMP-9 to predict the response to NAC and patient survival was studied.

Results

Of the 303 patients, 103 (34.0%) patients experienced pathological complete response (pCR) after completion of NAC. Univariate and multivariate analyses revealed that the relative change in sMMP-9, rather than sMMP-9 at baseline or surgery, had a remarkable predictive value for pCR. Each 1 ng/ml decrease in sMMP-9 after NAC was shown to result in a 0.3% increase in pCR rate. Additionally, in survival analyses, hMMP-9 expression in residual tumors was independently correlated with disease-free survival for non-pCR responders (P < 0.001).

Conclusions

Our findings indicate that monitoring serum MMP-9 and detection of histological MMP-9 could help identify TNBC patients who will respond to NAC and will display varying risks of disease relapse. MMP-9 may serve as a predictive and prognostic biomarker for tailoring and modifying the NAC strategy for TNBC.

PD-L1 expression of the residual tumor serves as a prognostic marker in local advanced breast cancer after neoadjuvant chemotherapy

This study sought to investigate the prevalence of programmed death ligand 1 (PD-L1) and its prognostic value in patients with residual tumors after neoadjuvant chemotherapy (NCT) for locally advanced breast cancer. A total of 309 patients considered as non-pathological complete responders (non-pCR) after NCT followed by mastectomy were selected. The expression of PD-L1 and tumor-infiltrating lymphocytes (TILs) in residual breast cancer cells was assessed by immunohistochemistry in surgical specimens. The median density was used to classify PD-L1 expression from low to high. The prognostic value of various clinicopathological factors was evaluated. The expression of PD-L1 was more commonly observed in patients with low levels of total TILs (p < 0.001), high levels of FOXP3+ TILs (p < 0.001) and low levels of CD8+ TILs (p < 0.001). This served as an independent prognostic factor for both relapse-free survival (Hazard ratio = 1.824, p = 0.013) and overall survival (OS) (Hazard ratio = 2.585, p = 0.001). High expression of PD-L1 was correlated to worse survival, which is most significantly observed in triple-negative patients. Patients classified as PD-L1-high/CD8-low exhibited relatively unfavorable survival, whereas patients with either low expression of PD-L1 or high expression of CD8 had similar outcomes. PD-L1 expression in residual tumor can be used as a prognostic marker in non-pCR patients after receiving NCT for breast cancer, which highlights the importance of immune evasion in the therapeutic vulnerability of chemoresistant cancer cells as well as the potential of anti-PD-L1 treatments in non-pCR responders.

Biomarkers Predicting Pathologic Complete Response to Neoadjuvant Chemotherapy in Breast Cancer

OBJECTIVES

Recent studies have shown strong correlation of pathologic complete response (pCR) to neoadjuvant chemotherapy with survival and prognosis in breast cancers.

METHODS

Clinical data from 237 breast cancer patients who received neoadjuvant chemotherapy between 2012 and 2014 were reviewed. Correlations were sought between pCR and estrogen receptor (ER), progesterone receptor (PR), and HER2 status; Nottingham and nuclear grades; tumor tubule formation; mitotic score; Ki67 index; and tumoral and stromal lymphocytic infiltration (TLI and SLI, respectively).

RESULTS

Of the 237 cases, 104 (43.9%) achieved pCR. The HER2+ and triple negative breast cancer (TNBC) subtypes had higher pCR rates compared with the luminal subtype (ER+ or PR+ and HER2-). ER and PR negativity, HER2 positivity, Nottingham grade 3, increased TLI and SLI, high mitotic count and Ki67 score correlated significantly with pCR in the overall cohort. TLI and SLI correlated significantly with pCR in the HER2+ and TNBC subtypes in multivariate analysis, whereas no biomarkers correlated with pCR in the luminal subtype.

CONCLUSIONS

In addition to the pathologic parameters and biomarkers already routinely assessed, evaluation of TLI and SLI may help to better select patients with HER2+ and TNBC for neoadjuvant chemotherapy.

Generation of an algorithm based on minimal gene sets to clinically subtype triple negative breast cancer patients

BACKGROUND

Recently, a gene expression algorithm, TNBCtype, was developed that can divide triple-negative breast cancer (TNBC) into molecularly-defined subtypes. The algorithm has potential to provide predictive value for TNBC subtype-specific response to various treatments. TNBCtype used in a retrospective analysis of neoadjuvant clinical trial data of TNBC patients demonstrated that TNBC subtype and pathological complete response to neoadjuvant chemotherapy were significantly associated. Herein we describe an expression algorithm reduced to 101 genes with the power to subtype TNBC tumors similar to the original 2188-gene expression algorithm and predict patient outcomes.

METHODS

The new classification model was built using the same expression data sets used for the original TNBCtype algorithm. Gene set enrichment followed by shrunken centroid analysis were used for feature reduction, then elastic-net regularized linear modeling was used to identify genes for a centroid model classifying all subtypes, comprised of 101 genes. The predictive capability of both this new "lean" algorithm and the original 2188-gene model were applied to an independent clinical trial cohort of 139 TNBC patients treated initially with neoadjuvant doxorubicin/cyclophosphamide and then randomized to receive either paclitaxel or ixabepilone to determine association of pathologic complete response within the subtypes.

RESULTS

The new 101-gene expression model reproduced the classification provided by the 2188-gene algorithm and was highly concordant in the same set of seven TNBC cohorts used to generate the TNBCtype algorithm (87%), as well as in the independent clinical trial cohort (88%), when cases with significant correlations to multiple subtypes were excluded. Clinical responses to both neoadjuvant treatment arms, found BL2 to be significantly associated with poor response (Odds Ratio (OR) =0.12, p=0.03 for the 2188-gene model; OR = 0.23, p < 0.03 for the 101-gene model). Additionally, while the BL1 subtype trended towards significance in the 2188-gene model (OR = 1.91, p = 0.14), the 101-gene model demonstrated significant association with improved response in patients with the BL1 subtype (OR = 3.59, p = 0.02).

CONCLUSIONS

These results demonstrate that a model using small gene sets can recapitulate the TNBC subtypes identified by the original 2188-gene model and in the case of standard chemotherapy, the ability to predict therapeutic response.

Clinical and pathological response to neoadjuvant chemotherapy based on primary tumor reduction is correlated to survival in hormone receptor-positive but not hormone receptor-negative locally advanced breast cancer

PURPOSE

This study was designed to examine the relationship between different methodologies for response evaluation and long-term survival estimation in patients underwent neoadjuvant chemotherapy (NCT) for breast cancer.

METHODS

We retrospectively analyzed 569 patients who were diagnosed with LABC and received NCT followed by breast and axilla surgery. The RECIST 1.1 criteria and Miller-Payne (MP) grading scale were used to evaluate patient responses to NCT. Univariate and multivariate survival analyses were performed to investigate the correlation between treatment response and long-term patient survival.

RESULTS

Clinical response (RFS [P < 0.001]; OS [P = 0.003]), pathological response evaluated by pCR (RFS [P < 0.001]; OS [P < 0.001]), and MP grade (RFS [P < 0.001]; OS [P < 0.001]) were significant predictors of risks of relapse and survival. However, in hormone receptor-positive (ER and/or PR+) subtypes, the clinical response (P = 0.004 for Luminal-A and P = 0.038 for Luminal-B) and MP grade (P = 0.002 for Luminal-A and P < 0.001 for Luminal-B) significantly predicted RFS independently according to multivariate Cox regression model. MP grade (P = 0.015 for Luminal-A and P = 0.009 for Luminal-B) also was an independent predictor of patients' OS. However, these two methods failed to predict patient survival in hormone receptor-negative (ER and PR-) subtypes.

CONCLUSIONS

Our findings indicate that the value of response evaluation methods varies for different breast cancer subtypes. Conceiving of further prospective approaches for new individualized response-evaluation models are needed in the neoadjuvant setting.

Neoadjuvant therapy in the treatment of breast cancer

Neoadjuvant systemic therapy in breast cancer treatment was initially utilized for inoperable disease. However, several randomized prospective studies have demonstrated comparable survival with adjuvant chemotherapy in early-stage, operable breast cancer while also decreasing tumor size facilitating breast conservation without significant increases in local recurrence. Response to therapy can predict outcome, with improved survival associated with pathologic complete response (pCR). Triple negative and HER2-positive subtypes show increased pCR rates. A multidisciplinary approach is necessary with neoadjuvant treatment. This can improve rates of breast conservation, provide insights into tumor biology and predict patient outcomes.

The residual tumor autophagy marker LC3B serves as a prognostic marker in local advanced breast cancer after neoadjuvant chemotherapy

PURPOSE

This study sought to investigate the prognostic value of the autophagy marker microtubule-associated protein chain 3B (LC3B) in patients with residual tumors after neoadjuvant chemotherapy (NCT) for locally advanced breast cancer (LABC).

PATIENTS AND METHODS

The expression of LC3B in residual breast cancer cells was assessed by immunohistochemistry in surgical specimens from 229 patients diagnosed with histologically proven invasive breast cancer. All patients underwent NCT followed by mastectomy and were considered nonpathologic complete responders (non-pCR) after a pathologic evaluation. The prognostic value of various clinicopathologic factors was evaluated.

RESULTS

The LC3B density was similar between the peripheral and central area of the tumors (P = 0.328) but was significantly lower in the extratumoral area (P < 0.001 and P < 0.001, respectively). Furthermore, LC3B density, which correlated with Beclin-1 expression, Ki-67 index, and breast cancer subtype, served as an independent prognostic factor for both relapse-free survival (RFS; P = 0.012) and overall survival (OS; P = 0.008); the prognostic value of LC3B was most significant in triple-negative patients. Using a combination of LC3B expression and the status of residual involved lymph nodes, the patients were classified into four groups with different risks of relapse and death (P < 0.001 for RFS and P = 0.003 for OS).

CONCLUSION

LC3B can be used as a prognostic marker in patients with non-pCR after NCT for breast cancer, which highlights the importance of autophagy in the biologic behavior of chemoresistant cancer cells. Furthermore, evaluating and targeting autophagy in the neoadjuvant setting may help prevent disease relapse in patients with non-pCR.

Unfavorable pathological complete response rate of neoadjuvant chemotherapy epirubicin plus taxanes for locally advanced triple-negative breast cancer

Anthracycline-Taxane chemotherapy is widely used in neoadjuvant treatment for breast cancers. However, there is limited data reported in patients with triple negative breast cancer (TNBC). Here, we evaluated the pathologic responses and survival of neoadjuvant epirubicin and taxanes chemotherapy in patients with locally advanced TNBC to provide some useful information for clinical practice. A total of 43 patients with locally advanced TNBC were enrolled in this study. Patients were administered with epirubicin 75 mg/m(2) plus paclitaxel 175 mg/m(2) or docetaxel 75 mg/m(2) every 3 weeks for at least 2 cycles. The primary endpoint was pathologic complete response (pCR), which was defined as no residual invasive cancer, or only carcinoma in situ in both the excised breast and axillary lymph node, while relapse-free survival (RFS) and overall survival (OS) were secondary endpoints. Thirty-nine (90.7%) patients were at clinical stages IIB-IIIC. Thirty-seven (86%) completed 4-6 cycles of preoperative chemotherapy, and objective response rate (ORR) was 81.4% (35/43). Forty-two patients underwent radical surgery subsequently. The pCR rate was 14.3% (6/42). The most common adverse events in neoadjuvant chemotherapy were nausea/vomiting (88.4%, 38/43) and neutropenia (88.4%). After a median follow-up period of 34.0 months, 3-year RFS and OS rate was 53.6% and 80.1%, respectively. All events of recurrence and death occurred in non-pCR patients, in whom the 3-year RFS and OS rates were 44.3% and 76.6%, respectively. This study suggest that neoadjuvant chemotherapy with epirubicin plus taxanes has a relatively low pCR rate and high early recurrence risk in locally advanced TNBC, which indicates the necessity for more efficacious treatment. Further study is needed to validate these results.

Downregulation of BCSG1 may correlate with better outcome of neoadjuvant chemotherapy for triple-negative breast cancer

The aim of this study was to investigate the correlation between breast cancer-specific gene 1 (BCSG1) and the effect of neoadjuvant chemotherapy (NAC) in patients with triple-negative breast cancer (TNBC). Real-time RT-PCR and immunohistochemistry were used to determine the expression of BCSG1 mRNA and protein levels of 32 TNBC patients before and after NAC. Tumor size was reduced significantly after NAC in all 32 TNBC patients. The expression of BCSG1 was also decreased after NAC at both mRNA and protein levels. There was a negative correlation between BCSG1 levels after NAC and the effect of NAC. BCSG1 may be a potential target for NAC in the treatment of TNBC.

Triple-negative and basal-like breast cancer: implications for oncologists

Since the start of the 1990s, molecular pathology has been playing an increasingly important role in cancer diagnosis and treatment.[...]

[Triple-negative breast carcinoma--rewiev of current literature]

Breast cancer is one of the most common malignancies in women. Approximately 15% of cases belong to the triple-negative breast cancer (TNBC) group, in which no estrogen/progesterone receptors, or HER2 expression is detected. The unfavorable prognosis of this group of patients, as well as the lack of effective targeted therapy makes TNBC the subject of intensive research. In the present study, we searched PubMed for publications from January 2007 to June 2009 with the following key-words in addition to "breast cancer" and "triple negative": "epidemiology" or "gene-profile" or "predictive" or "prognostic" or "therapy" or "review". A total of 513 publications were identified. Relevant references were also reviewed. Beyond the well-known facts that TNBC affects younger patients, and is more common among Afro- or Hispano-Americans with lower socioeconomic status, hormonal environment and obesity emerged as potential etiologic factors. TNBC is not a homogenous disease. It can be further sub-classified based on histomorphologic features and immunohistochemistry. Hereditary BRCA1 mutations as well as acquired BRCA1 disfunction are described to be common in TNBC. Previously, many investigators considered TNBC to be identical to a subgroup called basal-like breast cancer defined by gene expression micro-array technology, but in the light of more recent findings, this view is no longer accepted by most investigators. Several large studies provide evidence that triple negativity, per se, is an independent adverse prognostic factor, in spite of the fact that approximately 10% of TNBC patients have a good prognosis. The therapy of choice for TNBC is systemic chemotherapy. Promising novel targeted chemotherapeutic agents include PARP1 inhibitors, a new group of compounds exploiting the defective DNA repair machinery. Rubovszky G, Udvarhelyi N, Horváth Z, Láng I, Kásler M. Triple negative breast carcinoma - rewiev of current literature.