Pathological non-response to chemotherapy in a neoadjuvant setting of breast cancer: an inter-institutional study

Is Ki-67 Really Useful as a Predictor for Response to Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer?

Neoadjuvant chemotherapy (NACT) is routinely offered to operable locally advanced breast cancer (LABC) patients desirous of breast conservation surgery and inoperable LABC patients. Pathological complete response (pCR) following chemotherapy is recognized as a surrogate for survival outcomes in high grade tumour subtypes. Many biological and tumor characters have been shown to predict pCR. The current study was performed with the aim of investigating the ability of Ki-67 in predicting pCR with NACT in breast cancer patients. A total of 105 patients with locally advanced breast cancer who completed NACT followed by surgery were included in this study from January 2020 till December 2022. Patients with advanced metastatic breast carcinoma, who did not give consent for NACT, who did not complete NACT and who did not undergo surgery were excluded. All patients were assessed for Ki-67 score on core-needle biopsy samples and response rate was assessed clinically and by histopathological examination of resected specimen. Quantitative variables were compared using unpaired t-test or Mann-Whitney 'U' test and for categorical variables Chi-square or Fisher's exact test were used. Receiver operating characteristic (ROC) curve analysis was performed to assess the predictive potential of Ki-67 expression levels in predicting pCR. To identify the predictive factors associated with pCR, univariate analysis was performed. The P value < 0.05 was considered as statistically significant. Mean age was 51.57 ± 10.8 years. 51 patients achieved clinical complete response (cCR) and 33 achieved pCR after NACT. Mean Ki-67 index in overall study population, in pCR group and no pCR group was 46.44 ± 22.92%, 51.60 ± 22.3% and 44.06 ± 22.7%, respectively. On univariate analysis, ER negativity, PR negativity and Her 2neu positivity were found predictive of pCR. On subgroup analysis, TNBC and Her 2neu positive sub groups were associated with higher cCR and pCR rate. We found no significant association between Ki-67 and pCR. This result may be confounded by the fact that a significant duration of the study was in the COVID-19 pandemic. Validation of this data is required in a large prospective study.

Enhanced therapeutic efficacy of doxorubicin/cyclophosphamide in combination with pitavastatin or simvastatin against breast cancer cells

Fighting breast tumors mandates finding different agents devoid of chemotherapy side effects. Repurposing existing drugs, such as statins, presents a promising avenue for the development of novel cancer therapeutics. Based on the different effects of statin members, this study aims to evaluate the effect of two of the most promising lipophilic statins, Simvastatin and Pitavastatin, and their combination with a conventional chemotherapeutic regimen of doxorubicin and cyclophosphamide on breast cancer cells. MDA-MB-231 and MCF7 cell lines were used to analyze the effects of Pitavastatin and simvastatin in combination with doxorubicin/cyclophosphamide. Cell viability and cell cycle were analyzed and certain apoptosis-related genes such as Bax, Bcl2, and caspase-3, besides cyclin D1 were analyzed using qPCR. The viability of breast cancer cells decreased significantly after treatment with a doxorubicin/cyclophosphamide combination in the presence of Pitavastatin or simvastatin compared with dual doxorubicin/cyclophosphamide with a higher effect in MDA-MB-231 cells than MCF7. In MDA-MB-231, The triple combination of Pitavastatin or simvastatin with doxorubicin/cyclophosphamide resulted in an increase in the expression levels of apoptotic markers than treatment with doxorubicin/cyclophosphamide combination (Bax (p-value = 0.09& 0.02, respectively), Bax/Bcl2 ratio (p-value = 0.0002& <0.0001, respectively)). However, the increase in caspase3 wasn't significant (p-value = 0.45& 0.09, respectively). Moreover, the expression of cyclin D1 decreased (p-value = 0.0002& <0.0001, respectively) and the cell cycle was arrested in the G1 phase. Combination of Pitavastatin or simvastatin with doxorubicin/ cyclophosphamide may induce apoptosis in breast cancer cells via upregulation of the Bax/Bcl2 pathway, potentially providing a promising new therapeutic strategy for breast cancer.

Evaluation of the relationship between Ki67 expression level and neoadjuvant treatment response and prognosis in breast cancer based on the Neo-Bioscore staging system

BACKGROUND

Neoadjuvant chemotherapy (NAC) is widely used in the treatment of primary breast cancer. Different staging systems have been developed to evaluate the residual tumor after NAC and classify patients into different prognostic groups. Ki67, a proliferation marker, has been shown to be useful in predicting treatment response and prognosis. We aimed to investigate the prognostic importance Neo-Bioscore stage and pretreatment and posttreatment Ki67 levels in breast cancer patients who received NAC and correlations between Neo-Bioscore stage and pretreatment and posttreatment Ki67 levels.

METHODS

A total of 176 invasive breast carcinoma patients who underwent NAC were included in the study. Ki67 levels were evaluated by immunohistochemical methods in Trucut biopsy and surgical excision specimens. Patients were classified into prognostic groups using the Neo-Bioscore staging system.

RESULTS

Patients with high pretreatment Ki67 score were more likely to be in the higher Neo-Bioscore risk group (p < 0.001). Patients with a high posttreatment Ki67 score were more likely to be in the higher Neo-Bioscore prognostic risk group (p < 0.001). Overall survival (OS) and disease-free survival (DFS) were shorter in patients with high posttreatment Ki67 scores and in patients in the higher Neo-Bioscore risk group. We also determined a cutoff 37% for pathological complete response.

CONCLUSION

Neo-Bioscore staging system is found to be important in predicting survival. The posttreatment Ki67 level is more important than pretreatment Ki67 level in predicting survival.

Machine Learning Approach for the Determination of the Best Cut-off Points for Ki67 Proliferation Index in Adjuvant and Neo-adjuvant Therapy Breast Cancer Patients

BACKGROUND

This study aims to evaluate Ki67 cut-off points for differentiating low and high-risk patients based on survival and recurrence and find the best Ki67 cut-off points in breast cancer patients undergoing adjuvant and neoadjuvant therapy using machine learning methods.

PATIENTS AND METHODS

Patients with breast cancer treated at 2 referral hospitals between December 2000 and March 2021 who had invasive breast cancer entered this study. There were 257 patients in the neoadjuvant group and 2139 in the adjuvant group. A decision tree method was used to predict the likelihood of survival and recurrence. The 2-ensemble technique of RUSboost and bagged tree were imposed on the decision tree method to increase the accuracy of the determination. 80 percent of the data was used to train and validate the model, and 20% was used as a test.

RESULTS

In adjuvant therapy breast cancer patients with Invasive ductal carcinoma (IDC) and Invasive lobular carcinoma (ILC) the cutoff points for survival were 20 and 10, respectively. For luminal A, luminal B, Her2 neu, and triple-negative adjuvant therapy patients' the cutoff points for survival were 25, 15, 20, and 20, respectively. For neoadjuvant therapy luminal A and luminal B group, survival cutoff points were 25 and 20, respectively.

CONCLUSION

Despite variability in measurement and cut-off points, the Ki-67 proliferation index is still helpful in the clinic. Further investigation is needed to determine the best cut-off points for different patients. The sensitivity and specificity of Ki-67 cutoff point prediction models in this study could further prove its significance as a prognostic factor.

Novel Radiomic Measurements of Tumor-Associated Vasculature Morphology on Clinical Imaging as a Biomarker of Treatment Response in Multiple Cancers

PURPOSE

The tumor-associated vasculature (TAV) differs from healthy blood vessels by its convolutedness, leakiness, and chaotic architecture, and these attributes facilitate the creation of a treatment-resistant tumor microenvironment. Measurable differences in these attributes might also help stratify patients by likely benefit of systemic therapy (e.g., chemotherapy). In this work, we present a new category of computational image-based biomarkers called quantitative tumor-associated vasculature (QuanTAV) features, and demonstrate their ability to predict response and survival across multiple cancer types, imaging modalities, and treatment regimens involving chemotherapy.

EXPERIMENTAL DESIGN

We isolated tumor vasculature and extracted mathematical measurements of twistedness and organization from routine pretreatment radiology (CT or contrast-enhanced MRI) of a total of 558 patients, who received one of four first-line chemotherapy-based therapeutic intervention strategies for breast (n = 371) or non-small cell lung cancer (NSCLC, n = 187).

RESULTS

Across four chemotherapy-based treatment strategies, classifiers of QuanTAV measurements significantly (P < 0.05) predicted response in held out testing cohorts alone (AUC = 0.63-0.71) and increased AUC by 0.06-0.12 when added to models of significant clinical variables alone. Similarly, we derived QuanTAV risk scores that were prognostic of recurrence-free survival in treatment cohorts who received surgery following chemotherapy for breast cancer [P = 0.0022; HR = 1.25; 95% confidence interval (CI), 1.08-1.44; concordance index (C-index) = 0.66] and chemoradiation for NSCLC (P = 0.039; HR = 1.28; 95% CI, 1.01-1.62; C-index = 0.66). From vessel-based risk scores, we further derived categorical QuanTAV high/low risk groups that were independently prognostic among all treatment groups, including patients with NSCLC who received chemotherapy only (P = 0.034; HR = 2.29; 95% CI, 1.07-4.94; C-index = 0.62). QuanTAV response and risk scores were independent of clinicopathologic risk factors and matched or exceeded models of clinical variables including posttreatment response.

CONCLUSIONS

Across these domains, we observed an association of vascular morphology on CT and MRI-as captured by metrics of vessel curvature, torsion, and organizational heterogeneity-and treatment outcome. Our findings suggest the potential of shape and structure of the TAV in developing prognostic and predictive biomarkers for multiple cancers and different treatment strategies.

Anti-Cancer Effects of Cyclic Peptide ALOS4 in a Human Melanoma Mouse Model

We examined the effects of ALOS4, a cyclic peptide discovered previously by phage library selection against integrin α_vβ₃, on a human melanoma (A375) xenograft model to determine its abilities as a potential anti-cancer agent. We found that ALOS4 promoted healthy weight gain in A375-engrafted nude mice and reduced melanoma tumor mass and volume. Despite these positive changes, examination of the tumor tissue did not indicate any significant effects on proliferation, mitotic index, tissue vascularization, or reduction of αSMA or Ki-67 tumor markers. Modulation in overall expression of critical downstream α_vβ₃ integrin factors, such as FAK and Src, as well as reductions in gene expression of c-Fos and c-Jun transcription factors, indirectly confirmed our suspicions that ALOS4 is likely acting through an integrin-mediated pathway. Further, we found no overt formulation issues with ALOS4 regarding interaction with standard inert laboratory materials (polypropylene, borosilicate glass) or with pH and temperature stability under prolonged storage. Collectively, ALOS4 appears to be safe, chemically stable, and produces anti-cancer effects in a human xenograft model of melanoma. We believe these results suggest a role for ALOS4 in an integrin-mediated pathway in exerting its anti-cancer effects possibly through immune response modulation.

Cytoplasmic Cyclin E Expression Predicts for Response to Neoadjuvant Chemotherapy in Breast Cancer

BACKGROUND

Pathologic complete response (pCR) has been shown to be associated with favorable outcomes in breast cancer. Predictors of pCR could be useful in guiding treatment decisions regarding neoadjuvant therapy. The objective of this study was to evaluate cyclin E as a predictor of response to neoadjuvant chemotherapy in breast cancer.

METHODS

Patients (n = 285) with stage II-III breast cancer were enrolled in a prospective study and received neoadjuvant chemotherapy with anthracyclines, taxanes, or combination of the two. Pretreatment biopsies from 190 patients and surgical specimens following chemotherapy from 192 patients were available for immunohistochemical analysis. Clinical and pathologic responses were recorded and associated with presence of tumor infiltrating lymphocytes, cyclin E, adipophilin, programmed cell death-ligand 1, and elastase staining and other patient, tumor and treatment characteristics.

RESULTS

The pCR rate was significantly lower in patients with cytoplasmic cyclin E staining compared with those who had no cyclin E expression (16.1% vs 38.9%, P = 0.0005). In multivariable logistic regression analysis, the odds of pCR for patients who had cytoplasmic negative tumors was 9.35 times (P value < 0.0001) that compared with patients with cytoplasmic positive tumors after adjusting for ER, PR, and HER2 status. Cytoplasmic cyclin E expression also predicts long-term outcome and is associated with reduced disease free, recurrence free, and overall survival rates, independent of increased pretreatment tumor infiltrating lymphocytes.

CONCLUSIONS

Cyclin E independently predicted response to neoadjuvant chemotherapy. Hence, its routine immunohistochemical analysis could be used clinically to identify those breast cancer patients expected to have a poor response to anthracycline/taxane-based chemotherapy.

Prognostic and Clinicopathological Correlations of Cell Cycle Marker Expressions before and after the Primary Systemic Therapy of Breast Cancer

We aimed to analyze the expression of cell-cycle regulation markers - minichromosome maintenance protein 2 (MCM2), Ki-67, Cyclin-A and phosphohistone-H3 (PHH3) - in pre-treatment core-biopsy samples of breast carcinomas in correlation with known predictive and prognostic factors. Totally 52 core biopsy samples obtained prior to neoadjuvant therapy were analyzed. Immunohistochemistry was performed to analyze the expression of MCM2, Ki-67, Cyclin A and PHH3, which were correlated with the following clinicopathological parameters: clinical TNM, tumor grade, biological subtype, the presence of tumor infiltrating lymphocytes (TIL), pathological tumor response rate to the neoadjuvant therapy and patient survival. All investigated markers showed higher expression in high grade and in triple negative tumors (p < 0.01 and p < 0.05, respectively). Hormone receptor negative tumors showed significantly higher expression of Ki-67 (p < 0.01), MCM2 (p < 0.01) and Cyclin A (p < 0.01) than hormone receptor positive ones. Tumors with increased TIL showed significantly higher Ki-67 expression (p = 0.04). Pattern analysis suggested that novel cell-cycle marker-based subgrouping reveals predictive and prognostic potential. Tumors with high MCM2, Cyclin A or PHH3 expression showed significantly higher rate of pathological complete remission. Tumors with early relapse (progression-free survival ≤2 years) and shortened overall survival also show a higher rate of proliferation. Our cell cycle marker (Ki-67, MCM2, Cyclin A, PHH3) based testing could identify tumors with worse prognosis, but with a favorable response to primary systemic therapy. The pattern of cell-cycle activity could also be useful for predicting early relapse, but our findings need to be further substantiated in larger patient cohorts.

Circulating lncRNA H19 may be a useful marker of response to neoadjuvant chemotherapy in breast cancer

BACKGROUND

Novel biomarkers are needed to predict the effectiveness of the treatment of presurgical neoadjuvant chemotherapy (NAC) in breast cancer (BC).

OBJECTIVE

This is an exploratory study to assess the impact of 3 cancer-related long non-coding RNAs (lncRNAs) (H19, MALAT1 and GA5) in blood plasma of patients with BC in predicting the response to NAC.

METHODS

The plasma levels of RNAs were relatively measured by quantitative PCR at baseline, and at the end of the fourth cycle of NAC in patients with locally advanced BC.

RESULTS

Only H19 was associated with patients' characteristics, and with the response to NAC. Higher plasma expression of H19 was associated with younger age at diagnosis, triple negative tumors, and Ki-67 index. Patients with a pathological complete response (20%) had lower pre-therapeutic levels of H19 compared with the non-complete responders (relative levels 0.1 vs 0.2, respectively, P: 0.04). In addition, the patients with higher degree of downstaging of initial tumors had lower baseline levels of H19 among non-complete responders.

CONCLUSION

Our study reveals that H19, but not MALAT1 and GAS5, may be a useful marker of response to NAC in BC.

The Dilemma of HER2 Double-equivocal Breast Carcinomas: Genomic Profiling and Implications for Treatment

Supplemental Digital Content is available in the text.

The American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) 2013 guidelines for HER2 assessment have increased the number of HER2 equivocal breast carcinomas following in situ hybridization reflex testing, that is, HER2 “double equivocal” (equivocal protein expression and equivocal gene copy number). Forty-five double-equivocal carcinomas were subjected to Prosigna analysis. Twenty-seven cases were investigated for the expression of genes found to be differentially expressed between estrogen receptor (ER)-positive/HER2-positive (N=22) and ER-positive/HER2-negative (N=22) control cases. Twenty-nine of the 45 cases were also analyzed by targeted sequencing using a panel of 14 genes. We then explored the pathologic complete response rates in an independent series of double-equivocal carcinoma patients treated with trastuzumab-containing chemotherapy. All cases were ER-positive, with a mean Ki67 of 28%. Double-equivocal carcinomas were predominantly luminal B (76%); 9 cases (20%) were luminal A, and 2 cases (4%) HER2-enriched. The majority (73%) showed a high risk of recurrence by Prosigna, even when the carcinomas were small (<2 cm), node-negative/micrometastatic, and/or grade 2. Double-equivocal carcinomas showed TP53 (6/29, 20%), PIK3CA (3/29, 10%), HER2 (1/29, 3%), and MAP2K4 (1/29, 3%) mutations. Compared with grade-matched ER-positive/HER2-negative breast carcinomas from METABRIC, double-equivocal carcinomas harbored more frequently TP53 mutations and less frequently PIK3CA mutations (P<0.05). No significant differences were observed with grade-matched ER-positive/HER2-positive carcinomas. Lower pathologic complete response rates were observed in double-equivocal compared with HER2-positive patients (10% vs. 60%, P=0.009). Double-equivocal carcinomas are preferentially luminal B and show a high risk of recurrence. A subset of these tumors can be labeled as HER2-enriched by transcriptomic analysis. HER2 mutations can be identified in HER2 double-equivocal cases.

Prognostic value of pathologic complete response and the alteration of breast cancer immunohistochemical biomarkers after neoadjuvant chemotherapy

Neoadjuvant chemotherapy(NCT) has become the standard treatment for breast cancer. The information about the tumor's sensitivity to chemotherapy and prognostic significance based on response to therapy can be provided after individualized neoadjuvant treatment. The biomarkers are key factors in the decision-making process regarding treatment as well as important prognostic indicators. Studies have shown that patients who achieve pathological complete response(pCR) after NCT have a better prognosis. For patients who do not achieve pCR, the pathological characteristics of the residual tumor can make an effect on the survival. Furthermore, the immunohistochemical (IHC) markers of the residual diseases after primary systemic therapy might be different from the primary tumor. Estrogen receptor (ER), progesterone receptor (PR), and Ki67 can usually change after NCT, while human epidermal growth factor receptor 2(HER2) seems to be more stable. The relationship between changes in breast cancer molecular biomarkers and the prognosis after neoadjuvant therapy is not yet clear. The article will make a review about it.

Prediction of pathological complete response and prognosis in patients with neoadjuvant treatment for triple-negative breast cancer

Background

It has been reported that pathological complete response is an important surrogate marker for disease-free survival and overall survival in patients with triple-negative breast cancer. This study investigates predictors of the response to neoadjuvant platinum-based or anthracycline-based treatment, and of the prognosis, in patients with triple-negative breast cancer.

Methods

A total of 121 patients with triple-negative breast cancer received neoadjuvant treatment with either platinum or anthracycline between 2008 and 2013. Pathological complete response was assessed relative to different treatments using logistic regression models with age, clinical tumor stage, grading, and Ki-67 as predictors and interaction terms, to obtain adjusted and subgroup-specific results. The impact of the pathological complete response rate on disease-free survival and overall survival was also analyzed.

Results

The pathological complete response rate was higher after platinum/taxane treatment compared with anthracycline/taxane (50.0% vs. 41.8%), but this was not significant in the adjusted analysis (OR 1.44; 95% CI, 0.68 to 3.09). A high histological grade (G3) was a predictor for higher pathological complete response in platinum-based therapy (OR 2.27; 95% CI, 1.00 to 5.30). The effect of neoadjuvant chemotherapy on pathological complete response was significantly different for G1–2 vs. G3 (P_interaction = 0.013), and additional subgroup-specific differences were noted. Pathological complete response was a predictor for improved disease-free survival and overall survival in both treatment groups, with and without platinum chemotherapy.

Conclusions

This retrospective study of patients with triple-negative breast cancer adds to the evidence that the treatment effect of platinum may be greatest particularly in G3 tumors. In addition, the effect of pathological complete response on the prognosis does not depend on the treatment used.

Circulating Cell-Free DNA and Colorectal Cancer: A Systematic Review

There is a strong demand for the identification of new biomarkers in colorectal cancer (CRC) diagnosis. Among all liquid biopsy analysts, cell-free circulating DNA (cfDNA) is probably the most promising tool with respect to the identification of minimal residual diseases, assessment of treatment response and prognosis, and identification of resistance mechanisms. Circulating cell-free tumor DNA (ctDNA) maintains the same genomic signatures that are present in the matching tumor tissue allowing for the quantitative and qualitative evaluation of mutation burdens in body fluids. Thus, ctDNA-based research represents a non-invasive method for cancer detection. Among the numerous possible applications, the diagnostic, predictive, and/or prognostic utility of ctDNA in CRC has attracted intense research during the last few years. In the present review, we will describe the different aspects related to cfDNA research and evidence from studies supporting its potential use in CRC diagnoses and the improvement of therapy efficacy. We believe that ctDNA-based research should be considered as key towards the introduction of personalized medicine and patient benefits.

Predicting the response to neoadjuvant therapy for early-stage breast cancer: tumor-, blood-, and imaging-related biomarkers

Neoadjuvant therapy (NAT) has been used increasingly in patients with locally advanced or early-stage breast cancer. However, the accurate evaluation and prediction of response to NAT remain the great challenge. Biomarkers could prove useful to identify responders or nonresponders, or even to distinguish between early and delayed responses. These biomarkers could include markers from the tumor itself, such as versatile proteins, genes, and ribonucleic acids, various biological factors or peripheral blood cells, and clinical and pathological features. Possible predictive markers could also include multiple features from functional imaging, such as standard uptake values in positron emission tomography, apparent diffusion coefficient in magnetic resonance, or radiomics imaging biomarkers. In addition, cells that indirectly present the immune status of tumor cells and/or their host could also potentially be used as biomarkers, eg, tumor-infiltrating lymphocytes, tumor-associated macrophages, and myeloid-derived suppressor cells. Though numerous biomarkers have been widely investigated, only estrogen and/or progesterone receptors and human epidermal growth factor receptor have been proven to be reliable biomarkers to predict the response to NAT. They are the only biomarkers recommended in several international guidelines. The other aforementioned biomarkers warrant further validation studies. Some multigene profiling assays that are commercially available, eg, Oncotype DX and MammaPrint, should be used with caution when extrapolated to NAT settings. A panel of combined multilevel biomarkers might be able to predict the response to NAT more robustly than individual biomarkers. To establish such a panel and its prediction model, reliable methods and extensive clinical validation are warranted.

Neoadjuvant endocrine therapy with exemestane followed by response-guided combination therapy with low-dose cyclophosphamide in postmenopausal patients with estrogen receptor-positive breast cancer: A multicenter, open-label, phase II study

Patients with estrogen receptor (ER)‐positive breast cancer are less likely to achieve a pathological complete response (pCR) with neoadjuvant chemotherapy. Neoadjuvant endocrine therapy may be more appropriate than neoadjuvant chemotherapy in these hormone‐sensitive patients. Most patients with ER‐positive breast cancer are postmenopausal, and therefore, generally older and less able to tolerate chemotherapy. We aimed to investigate the efficacy and safety of tailored neoadjuvant endocrine and chemoendocrine therapy for postmenopausal breast cancer patients. Untreated patients with primary invasive ER‐positive, HER2‐negative, stage I‐IIIA breast cancer, and Ki67 index ≤30% were enrolled. Patients received exemestane 25 mg/d for 12 weeks. Based on clinical response and change in Ki67 index, assessed at 8‐12 weeks, patients with complete response (CR), partial response (PR) with Ki67 index ≤5% after treatment, or stable disease (SD) with Ki67 index ≤5% before and after treatment were defined as responders. For the subsequent 24 weeks, responders continued exemestane monotherapy (group A), and nonresponders received exemestane 25 mg/d plus cyclophosphamide 50 mg/d (group B). The primary endpoint was clinical response at weeks 24 and 36. A total of 59 patients (median age, 69 years) started initial exemestane monotherapy. After exclusion of three patients who discontinued during this period, 56 remained enrolled to receive subsequent treatment. Clinical response rates (CR and PR) and 95% CI at weeks 24 and 36 were 85% (12/14; 57.2%‐98.2%) and 71% (10/14; 41.9%‐91.6%), respectively, in group A; and 54% (23/42; 38.7%‐70.2%) and 71% (30/42; 55.4%‐84.3%), respectively, in group B. At week 36, no significant difference was found in median Ki67 index between the groups (3.5% and 4.0%). There were no treatment‐related deaths. We found that clinical response comparable to that of responders was achieved in nonresponders after addition of cyclophosphamide to the initial endocrine therapy.

Molecular Classification of Breast Cancer

Breast cancer is a heterogeneous disease, observed traditionally by morphology and protein expression but, more recently with the advent of modern molecular technologies, at the genomic and transcriptomic level. This review describes the association between the different molecular subtypes with the histologic subtypes of breast cancer alongside some of their major genomic characteristics and illustrates how these subtypes may affect the appearance of tumors on imaging studies. The authors aim to show how molecular stratification can be used to augment traditional methods to improve our understanding of breast cancers and their clinical management.

Mitotic Spindle Assembly and Genomic Stability in Breast Cancer Require PI3K-C2α Scaffolding Function

Proper organization of the mitotic spindle is key to genetic stability, but molecular components of inter-microtubule bridges that crosslink kinetochore fibers (K-fibers) are still largely unknown. Here we identify a kinase-independent function of class II phosphoinositide 3-OH kinase α (PI3K-C2α) acting as limiting scaffold protein organizing clathrin and TACC3 complex crosslinking K-fibers. Downregulation of PI3K-C2α causes spindle alterations, delayed anaphase onset, and aneuploidy, indicating that PI3K-C2α expression is required for genomic stability. Reduced abundance of PI3K-C2α in breast cancer models initially impairs tumor growth but later leads to the convergent evolution of fast-growing clones with mitotic checkpoint defects. As a consequence of altered spindle, loss of PI3K-C2α increases sensitivity to taxane-based therapy in pre-clinical models and in neoadjuvant settings.

Ki-67 as a controversial predictive and prognostic marker in breast cancer patients treated with neoadjuvant chemotherapy

BACKGROUND

Studies have partly demonstrated the clinical validity of Ki-67 as a predictive marker in the neoadjuvant setting, but the question of the best cut-off points as well as the importance of this marker as a prognostic factor in partial responder/non-responder groups remains uncertain.

METHODS

One hundred twenty patients diagnosed with invasive breast cancer and treated with neoadjuvant chemotherapy (NAC) between 2002 and 2013 were retrospectively recruited to this study. The optimal cut-off value for Ki-67 labeling index (LI) to discriminate response to treatment was assessed by receiver operating characteristic (ROC) curve analysis. Kaplan-Meier curve estimation, log-rank test and cox regression analysis were carried out to reveal the association between Ki-67 categories and survival (DMFS = Distant metastases-free survival, OS = Overall survival).

RESULTS

Twenty three out of 120 patients (19.2%) achieved pathologic complete remission (pCR), whereas partial remission (pPR) and no response (pNR) to neoadjuvant chemotherapy (NAC) was detected in 60.8% and 20.0%, respectively. The distribution of subtypes showed a significant difference in pathological response groups (p < 0.001). Most of the TNBC cases were represented in pCR group. The most relevant cut-off value for the Ki-67 distinguishing pCR from pNR cases was 20% (p = 0.002). No significant threshold for Ki-67 was found regarding DMFS (p = 0.208). Considering OS, the optimal cut-off point occurred at 15% Ki-67 (p = 0.006). The pPR group represented a significant Ki-67 threshold at 30% regarding OS (p = 0.001). Ki-67 and pPR subgroups were not significantly associated (p = 0.653). For prognosis prediction, Ki-67 at 30% cut-off value (p = 0.040) furthermore subtype (p = 0.037) as well as pathological response (p = 0.044) were suitable to separate patients into good and unfavorable prognosis cohorts regarding OS. However, in multivariate analyses, only Ki-67 at 30% threshold (p = 0.029), and subtype (p = 0.008) were independently linked to OS.

CONCLUSIONS

NAC is more efficient in tumors with at least 20% Ki-67 LI. Both Ki-67 LI and subtype showed a significant association with pathological response. Ki-67 LI represented independent prognostic potential to OS in our neoadjuvant patient cohort, while pathological response did not. Additionally, our data also suggest that if a tumor is non-responder to NAC, increased Ki-67 is a poor prognostic marker.

Neoadjuvant chemotherapy in breast cancers

With advances in science and technology, there are more innovations in the approach to management of patients with breast cancer. Neoadjuvant chemotherapy that is designed to be used prior to surgical removal of a tumor has received significant attention. Currently, neoadjuvant chemotherapy is offered to patients with locally advanced breast cancer and also those breast cancer patients who may benefit from size reduction before conservation therapy. There is now sufficient evidence that if neoadjuvant chemotherapy leads to complete pathologic response, the patient will enjoy a better outcome. Therefore, assessment of the degree of response to neoadjuvant chemotherapy has a major impact on patient selection and the follow-up management of each patient and defines patient outcome.

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.

Expression of cell cycle markers is predictive of the response to primary systemic therapy of locally advanced breast cancer

We aimed to analyze to what extent expression of four cell cycle regulation markers-minichromosome maintenance protein (MCM2), Ki-67, cyclin A, and phosphohistone-H3 (PHH3)-predict response to primary systemic therapy in terms of pathological complete remission (pCR). In search of an accurate and reproducible scoring method, we compared computer-assisted (CA) and routine visual assessment (VA) of immunoreactivity. We included 57 patients with breast cancer in the study. The cell cycle markers were detected using immunohistochemistry on pre-therapy core biopsy samples. Parallel CA (validated by manual labeling) and standard VA were performed and compared for diagnostic agreement and predictive value for pCR. CA and VA results were dichotomized based on receiver operating characteristic analysis defined optimal cut-off values. "High" was defined by staining scores above the optimal cut-off, while "low" had staining scores below the optimal cut-off. The CA method resulted in significantly lower values for Ki-67 and MCM2 compared to VA (mean difference, -3.939 and -4.323). Diagnostic agreement was highest for cyclin A and PHH3 (-0.586 and -0.666, respectively). Regardless of the method (CA/VA) used, all tested markers were predictive of pCR. Optimal cut-off-based dichotomization improved diagnostic agreement between the CA and VA methods for every marker, in particular for MCM2 (κ = 1, p < 0.000). Cyclin A displayed excellent agreement (κ = 0.925; p < 0.000), while Ki-67 and PHH3 showed good agreement (κ = 0.789, p < 0.000 and κ = 0.794, p < 0.000, respectively). We found all cell cycle markers (Ki-67, MCM2, cyclin A, and PHH3) predictive of pCR. Diagnostic agreement between CA and VA was better at lower staining scores but improved after optimal cut-off-based dichotomization.

Tumor slice culture system to assess drug response of primary breast cancer

BACKGROUND

The high incidence of breast cancer has sparked the development of novel targeted and personalized therapies. Personalization of cancer treatment requires reliable prediction of chemotherapy responses in individual patients. Effective selection can prevent unnecessary treatment that would mainly result in the unwanted side effects of the therapy. This selection can be facilitated by characterization of individual tumors using robust and specific functional assays, which requires development of powerful ex vivo culture systems and procedures to analyze the response to treatment.

METHODS

We optimized culture methods for primary breast tumor samples that allowed propagation of tissue ex vivo. We combined several tissue culture strategies, including defined tissue slicing technology, growth medium optimization and use of a rotating platform to increase nutrient exchange.

RESULTS

We could maintain tissue cultures for at least 7 days without losing tissue morphology, viability or cell proliferation. We also developed methods to determine the cytotoxic response of individual tumors to the chemotherapeutic treatment FAC (5-FU, Adriamycin [Doxorubicin] and Cyclophosphamide). Using this tool we designated tumors as sensitive or resistant and distinguished a clinically proven resistant tumor from other tumors.

CONCLUSION

This method defines conditions that allow ex vivo testing of individual tumor responses to anti-cancer drugs and therefore might improve personalization of breast cancer treatment.

High Expression of Pyruvate Kinase M2 is Associated with Chemosensitivity to Epirubicin and 5-Fluorouracil in Breast Cancer

BACKGROUND

Pyruvate kinase M2 (PKM2) is the key enzyme in the Warburg effect, and it was recently reported to be involved in the metabolic pathways of chemotherapeutic drugs. However, the role of PKM2 in breast cancer and its influence in the sensitivity to front-line anticancer drugs remains unclear.

METHODS

In this study, we examined the correlation between the expression of PKM2 and the sensitivity of primary breast cancer cells to anticancer drugs. PKM2 expression was studied by immunohistochemistry using biopsy samples of 296 patients diagnosed with invasive breast carcinoma, and the collagen gel droplet embedded culture-drug sensitivity tests (CD-DST) was conducted to all the patients to detect in vitro chemosensitivity after surgery.

RESULTS

We found high PKM2 expression was significantly associated with in vitro chemosensitivity to epirubicin (EPI) (P=0.019) and 5-fluorouracil (5-Fu) (P=0.009) in breast cancer patients. Then we used a small group of neoadjuvant chemotherapy cases to confirm that the higher PKM2 expression, the better pathological response to therapy was obtained in patients treated with EPI-based or EPI plus 5-Fu chemotherapy regimens. Although univariate and multivariate analysis indicated that high PKM2 was a poor independent predictor of progression free survival (PFS) and overall survival (OS) in breast cancer, patients with PKM2 high expression who received EPI-based or EPI plus 5-Fu chemotherapy were found to have a longer PFS (P=0.003, P=0.013) and OS (P=0.003, P=0.004) than patients treated with non-EPI/5-Fu-based regimens, respectively.

CONCLUSIONS

Our findings confirmed the poor prognosis of high PKM2 expression in breast cancer patients and revealed the predictive value of high PKM2 in the therapeutic response to EPI and 5-Fu. Moreover, our results provide the guidance of individual treatment for breast cancer patients who are foreboded a poor prognosis by the presence of high PKM2 status.

International Expert Consensus on Primary Systemic Therapy in the Management of Early Breast Cancer: Highlights of the Fifth Symposium on Primary Systemic Therapy in the Management of Operable Breast Cancer, Cremona, Italy (2013)

Expert consensus-based recommendations regarding key issues in the use of primary (or neoadjuvant) systemic treatment (PST) in patients with early breast cancer are a valuable resource for practising oncologists. PST remains a valuable therapeutic approach for the assessment of biological antitumor activity and clinical efficacy of new treatments in clinical trials. Neoadjuvant trials provide endpoints, such as pathological complete response (pCR) to treatment, that potentially translate into meaningful improvements in overall survival and disease-free survival. Neoadjuvant trials need fewer patients and are less expensive than adjuvant trial, and the endpoint of pCR is achieved in months, rather than years. For these reasons, the neoadjuvant setting is ideal for testing emerging targeted therapies in early breast cancer. Although pCR is an early clinical endpoint, its role as a surrogate for long-term outcomes is the key issue. New and better predictors of treatment efficacy are needed to improve treatment and outcomes. After PST, accurate management of post-treatment residual disease is mandatory. The surgery of the sentinel lymph-node could be an acceptable option to spare the axillary dissection in case of clinical negativity (N0) of the axilla at the diagnosis and/or after PST. No data exists yet to support the modulation of the extent of locoregional radiation therapy on the basis of the response attained after PST although trials are underway.