Alteration of HER2 Status During Breast Cancer Progression: A Clinicopathological Analysis Focusing on HER2-Low Status.

Recent studies have shown that novel antibody-drug conjugates (ADCs) can improve clinical outcomes in patients with HER2-low breast cancers. This study aimed to investigate alteration of HER2 status during breast cancer progression with an emphasis on HER2-low status. Using 386 paired samples of primary and recurrent breast cancers, HER2 discordance rate between primary and matched recurrent samples, the relationships between HER2 discordance and clinicopathological characteristics and clinical outcomes of the patients were analyzed. HER2 discordance rate between primary breast cancer and first recurrence was 25.9% (κ = 0.586) with mostly zero-to-low (10.6%) or low-to-zero (9.3%) conversion. There was no significant difference in the discordant rates according to type or location of the recurrence. Of 70 cases with a second recurrence, HER2 discordance rate between the primary tumor and the second recurrence was 27.1% (κ = 0.554). HER2 discordance was associated with lower HER2 level, lymphovascular invasion, and progesterone receptor positivity of the primary tumor. In further analyses, HER2-zero-to-low conversion was associated with lymph node metastasis and hormone receptor (HR) positivity, whereas HER2-low-to-zero conversion was associated with HR negativity and triple-negative subtype. In survival analyses, HER2 discordance was associated with decreased overall survival of patients in the HR-positive group but not in the HR-negative group. Furthermore, patients with HER2-low-to-zero converted tumors showed worse overall survival compared with those with HER2-low concordant tumors. In conclusion, HER2 status changes during breast cancer progression in significant proportions, mostly between zero and low status. As HER2 instability increases during progression and affects clinical outcome, HER2 status needs to be reevaluated in recurrent settings.

Prognostic significance of S100A8-positive immune cells in relation to other immune cell infiltration in pre-invasive and invasive breast cancers.

Myeloid-derived suppressor cells (MDSCs) play an important role in tumor progression through both immunologic and non-immunologic mechanisms. This study was conducted to evaluate the expression of S100A8, a well-known MDSC marker, and the significance of its expression in pre-invasive and invasive breast cancers. S100A8 expression in tumor cells (TCs) and immune cells (ICs) was assessed by immunohistochemistry, and its association with clinicopathologic features and infiltration of other IC subsets including CD4+, CD8+, and FOXP3+ tumor-infiltrating lymphocytes (TILs) and PD-L1+ ICs was evaluated. S100A8 expression in TCs and ICs showed a positive correlation in pre-invasive carcinoma and invasive carcinoma. S100A8+ ICs, but not S100A8+ TCs, were significantly higher in number in invasive carcinoma than in pre-invasive carcinoma. Infiltration of S100A8+ ICs was revealed as a poor prognostic indicator in pre-invasive and invasive carcinomas, especially in hormone receptor-positive subgroup. Infiltration of CD4+, CD8+, and FOXP3+ TIL subsets and PD-L1+ ICs was significantly higher in S100A8+ IC (+) group than in S100A8+ IC (-) group. Combined analyses of IC subset infiltration revealed that infiltration of S100A8+ ICs was associated with poor clinical outcome in the PD-L1+ IC (-), CD8+ TIL-low, and FOXP3+ TIL-low subgroups. In conclusion, S100A8+ ICs seem to undergo a dynamic change during breast cancer progression in association with other IC subset infiltration. The prognostic impact of S100A8+ IC infiltration was greater in less immunogenic tumors.

Immune microenvironment in ductal carcinoma in situ: a comparison with invasive carcinoma of the breast.

BACKGROUND: The immune microenvironment in ductal carcinoma in situ (DCIS) and its significance are not well established. This study was conducted to evaluate the immune microenvironment of DCIS including the composition of tumor-infiltrating lymphocyte (TIL) subsets and PD-L1+ immune cells and to compare it with that of invasive breast cancer. MATERIALS AND METHODS: A total of 671 cases including three different disease groups of pure DCIS, DCIS with microinvasion (DCIS-M), and invasive carcinoma were included in this study. CD4+, CD8+, and FOXP3+ TIL subsets and PD-L1+ immune cells were detected with immunohistochemistry using tissue microarrays and were analyzed in relation to clinicopathologic characteristics and different disease groups. RESULTS: In pure DCIS, high infiltrations of CD4+, CD8+, and FOXP3+ T cells and the presence of PD-L1+ immune cells were associated with high nuclear grade, comedo-type necrosis, hormone receptor (HR) negativity, and high Ki-67 proliferation index. All immune cell infiltrations were higher in invasive carcinoma than in pure DCIS regardless of the HR status. While CD4+ T cells were more abundant than CD8+ T cells in pure DCIS, CD8+ T cells were dominant in invasive carcinoma, especially in HR-negative tumors. Within individual cases of invasive carcinoma with DCIS component, all immune cell subset infiltration was higher in the invasive component than in the DCIS component; however, CD4+ TIL infiltration did not differ between the two components in HR-negative tumors. Comparing pure DCIS, DCIS-M, and DCIS associated with invasive carcinoma (DCIS-INV), CD4+ TIL infiltration revealed a gradual increase from pure DCIS to DCIS-M and DCIS-INV in the HR-negative group, whereas FOXP3+ TIL infiltration was significantly increased in DCIS-INV than in pure DCIS in the HR-positive group. The high infiltration of FOXP3+ TIL and the presence of PD-L1+ immune cells were associated with tumor recurrence in patients with pure DCIS. CONCLUSIONS: Our study showed that the immune microenvironment differs significantly not only between DCIS and invasive carcinoma but also between pure DCIS, DCIS-M, and DCIS-INV depending on the HR status.

Utility of a formatted pathologic reporting system in thyroid core needle biopsy: A validation study of 1998 consecutive cases.

OBJECTIVE: Thyroid core needle biopsy (CNB) is increasingly being used as a tool for evaluating thyroid nodules; thus, standardization of its diagnostic terminology is called for. We aimed to analyse the pathologic reporting system of thyroid CNB based on the recently proposed protocol by the Korean Endocrine Pathology Thyroid Core Needle Biopsy Study Group and evaluate its usefulness. DESIGN/METHODS: A total of 1998 consecutive cases of thyroid CNBs were reviewed and divided into six categories according to the protocol. Malignancy rate in each category and the diagnostic performance of thyroid CNB were calculated using 705 resected cases. RESULTS: Thyroid CNB yielded 132 nondiagnostic (6.6%), 791 benign (39.6%), 328 indeterminate (16.4%), 227 follicular neoplasm (11.4%), 69 suspicious for malignancy (3.5%) and 451 malignant lesions (22.6%). In resected specimens, all of the cases designated as suspicious for malignancy and malignant categories in CNB were proven to be true malignant lesions. Lesions diagnosed with follicular neoplasm in CNB were identified as malignant lesions in 57.0%. Malignancy rate was significantly higher in indeterminate lesions with nuclear atypia compared to those with architectural atypia (80.0% vs 28.2%). When CNB diagnoses of indeterminate lesions or higher categories were considered positive, the sensitivity and positive predictive value for final malignant diagnoses were 99.2% and 81.3%, respectively. CONCLUSIONS: CNB is an accurate method of evaluating thyroid nodules and can serve as an alternative to fine needle aspiration when it is used and reported according to standardized diagnostic categories.

Prognostic value of tumor infiltrating lymphocyte subsets in breast cancer depends on hormone receptor status.

PURPOSE: Interaction between immune-regulatory proteins and tumor infiltrating lymphocytes (TILs) is complex, and their associations may have significant clinical implications. This study was designed to evaluate the relationships between immunomodulatory proteins and TIL subsets and their impact on prognosis in breast cancer. METHODS: 377 invasive breast cancer cases were selected, and immunohistochemistry was performed for HLA-A, HLA-ABC, and indoleamine 2,3-dioxygenase (IDO); CD4+, CD8+, and FOXP3+ T cells were counted in intratumoral and stromal areas for both absolute numbers as well as their ratios. RESULTS: While HLA-ABC and HLA-A expressions showed a positive correlation with CD8+ and FOXP3+ TIL infiltration, IDO expression showed a negative correlation with FOXP3+/CD4+ and FOXP3+/CD8+ T cell ratios. Expressions of HLA-ABC, HLA-A, and IDO shared an association with negative estrogen receptor status. Infiltration of CD4+, CD8+, and FOXP3+ TILs was significantly higher in tumors with high histologic grade, negative hormone receptor status, HER2 amplification, high Ki-67 index, and p53 overexpression. In survival analyses, increased CD4+ TIL infiltration was associated with better prognosis of the patients while other TIL subset infiltration and expression of immunomodulatory proteins had no prognostic significance. In subgroup analyses, high CD4+ TIL infiltration was revealed as an independent good prognostic factor in hormone receptor-negative subgroup while high FOXP3+/CD8+ T cell ratio was found to be an independent adverse prognostic factor in hormone receptor-positive subgroup, especially in luminal A subtype. CONCLUSION: CD4+ TIL subset and FOXP3+/CD8+ T cell ratio have different prognostic significance in breast cancer according to hormone receptor status.

SIRT1 induces tumor invasion by targeting epithelial mesenchymal transition-related pathway and is a prognostic marker in triple negative breast cancer.

Absence of therapeutic targets poses a critical hurdle in improving prognosis for patients with triple negative breast cancer (TNBC). We evaluated interaction between SIRT1 and epithelial mesenchymal transition (EMT)-associated proteins as well as the role of combined protein expression as a predictor of lymph node metastasis and clinical outcome in TNBC through in vivo and vitro studies. Three hundred nineteen patients diagnosed with TNBC were chosen, immunohistochemical staining for SIRT1 and EMT-related markers' expression was performed on tissue microarrays, and in vitro experiments with each of the three human TNBC cell lines were carried out. The cohort was reclassified according to the use of adjuvant chemotherapy, tumor size, and AJCC stage to analyze the prognostic role of SIRT1 and EMT-related proteins' expression considering different therapeutic modalities and AJCC stages. Combination of four proteins including SIRT1 and three EMT-related proteins was revealed to be a statistically significant independent predictor of lymph node metastasis in the tumor size cohort as well as in the total patient population. Upon Cox regression analysis, increased expression level of the combined proteins correlated with decreased disease-free survival in the total patients as well as those who received adjuvant chemotherapy and those who had early stage breast cancer. In additional in vitro experiments, inhibition of SIRT1 expression with small interfering RNA (siRNA) suppressed tumor invasion in three different TNBC cell lines, and altered expression levels of EMT-related proteins following SIRT1 gene inhibition were identified on western blotting and fluorescence activated cell sorting (FACS) analysis; on the other hand, no change in expression levels of the cell cycle-related factors was observed. Our analysis showed the potential role of SIRT1 in association with EMT-related factors on tumor invasion, metastasis, and disease-free survival in TNBC, SIRT1, and associated EMT-related markers may offer a new prognostic indicator as well as a novel therapeutic candidate.

New insight on the biological role of p53 protein as a tumor suppressor: re-evaluation of its clinical significance in triple-negative breast cancer.

While p53 mutation is found in the majority of triple-negative breast cancer (TNBC) and despite recent developments in p53-targeting agents, their therapeutic application is still limited by the absence of standard biomarkers and ambiguousness of its essential biological role in cancer. Whole sections from 305 TNBC cases were stained for p53 to determine the correlation with lymph node metastasis and clinical outcomes in the whole cohort as well as in stratified patient groups according to AJCC stage and the use of adjuvant chemotherapy. Reduced immunohistochemical expression of p53 was an independent risk factor for lymph node metastasis. p53 overexpression was predictive of better clinical outcome in all patients (P = 0.012, disease-free survival and P = 0.008, overall survival) and the stratified cohorts of those who had early breast cancer and received adjuvant chemotherapy. Suppression of endogenous mutant p53 by siRNA and induction of wild-type p53 repressed TNBC cell invasion in vitro. In TNBC, increased immunohistochemical expression of p53 may reflect the accumulation of wild-type p53 rather than the mutant form. Strong p53 protein expression may serve as a favorable prognostic indicator and provide evidence for the use of specific agents targeting p53.

Assessment of HER2 status in invasive breast cancers with increased centromere 17 copy number.

This study was designed to evaluate usefulness of additional fluorescence in situ hybridization (FISH) using other reference genes on chromosome 17 for assessment of HER2 status in invasive breast cancers with increased centromere 17 copy number, and to compare this approach with conventional methods based on the 2007 and 2013 ASCO/CAP guidelines. We performed FISH with probes for SMS, RARA, and TP53 on 253 breast cancers with centromeric probe CEP17 copy number ≥ 2.6 using tissue microarrays. If one or more gene had a mean copy number <2.6, the largest number for that gene(s) was chosen as an alternative to CEP17 copy number. Of the 243 cases in which re-grading was possible, only 2 had copy numbers ≥ 2.6 for RARA, SMS, and TP53. Of the 151 breast cancers which were considered HER2 non-amplified by the 2007 ASCO/CAP guidelines using the HER2:CEP17 ratio, 42 (27.8%) were re-graded as amplified and 33 (21.8%) as equivocal after FISH using additional reference genes. Of the 101 HER2-non-amplified cases by the 2013 ASCO/CAP guidelines, 2 (2.0%) were reclassified as amplified and 24 (23.8%) as equivocal. Of 46 equivocal cases, 35 (76.1%) were re-graded as amplified. After re-grading, HER2-amplified cases were significantly increased, and the concordance between HER2 FISH and HER2 immunohistochemistry decreased. And some pathologic features of the cases which were designated to have HER2 amplification after additional FISH were not compatible with those of HER2-amplified breast cancers. The use of additional reference genes has been suggested as an option for accurate assessment of HER2 status in breast cancers with increased CEP17 copy number. However, this has limitations in that it can cause over-grading of HER2 status in tumors that lose the new reference genes. Thus, at present, it seems that additional FISH using other reference gene such as SMS, RARA, and TP53 for the cases with increased CEP17 copy number is not suitable for daily practice.

MicroRNA-9 is associated with epithelial-mesenchymal transition, breast cancer stem cell phenotype, and tumor progression in breast cancer.

MicroRNAs (miRNAs) are involved in the progression of breast cancer. Some miRNAs, especially the miR-200 family, miR-9, and miR-155 have been reported to be associated with epithelial-mesenchymal transition (EMT) and breast cancer stem cell (BCSC) phenotypes. This study was designed to evaluate the expression levels of these miRNAs in human breast cancer samples and analyzed their relationship with clinicopathologic features of the tumor including breast cancer subtype, EMT, BCSC phenotype, and prognosis. Expression levels of the miR-200 family, miR-9, and miR-155 were quantified using qRT-PCR. Breast cancer subtype, BCSC phenotype (CD44+/CD24- and ALDH1+), and expression of EMT markers (vimentin expression and E-cadherin loss) were evaluated by immunohistochemistry. miR-9 was more highly expressed in HER2+ and triple-negative subtypes than in luminal subtypes. Its expression level was significantly higher in tumors with high T stage, high histologic grade, p53 overexpression, and high proliferation index. Expression of miR-9 was also higher in tumors showing the CD44+/CD24- phenotype, vimentin expression, and E-cadherin loss. Furthermore, high level of miR-9 expression was found to be an independent prognostic factor for poor disease-free survival of the patients. Expression of miR-200a and miR-141 was highest in luminal A subtype, and miR-155 expression was highest in triple-negative subtype. Although the expression levels of some miR-200 family members and miR-155 showed difference with regard to EMT or BCSC phenotype, they were not associated with patients' prognosis. In conclusion, overexpression of miR-9 is found in tumors with aggressive phenotypes and is associated with poor prognosis in breast cancer, suggesting that it may serve as a potential biomarker for breast cancer progression and a target for treatment.

Comparative analysis of high- and low-level deep learning approaches in microsatellite instability prediction.

Deep learning-based approaches in histopathology can be largely divided into two categories: a high-level approach using an end-to-end model and a low-level approach using feature extractors. Although the advantages and disadvantages of both approaches are empirically well known, there exists no scientific basis for choosing a specific approach in research, and direct comparative analysis of the two approaches has rarely been performed. Using the Cancer Genomic Atlas (TCGA)-based dataset, we compared these two different approaches in microsatellite instability (MSI) prediction and analyzed morphological image features associated with MSI. Our high-level approach was based solely on EfficientNet, while our low-level approach relied on LightGBM and multiple deep learning models trained on publicly available multiclass tissue, nuclei, and gland datasets. We compared their performance and important image features. Our high-level approach showed superior performance compared to our low-level approach. In both approaches, debris, lymphocytes, and necrotic cells were revealed as important features of MSI, which is consistent with clinical knowledge. Then, during qualitative analysis, we discovered the weaknesses of our low-level approach and demonstrated that its performance can be improved by using different image features in a complementary way. We performed our study using open-access data, and we believe this study can serve as a useful basis for discovering imaging biomarkers for clinical application.

miR-145, miR-205 and miR-451: potential tumor suppressors involved in the progression of in situ to invasive carcinoma of the breast.

BACKGROUND: MicroRNAs (miRNAs) control diverse biologic processes during tumor progression. This study was conducted to identify miRNAs that are implicated in progression of in situ to invasive breast cancer (IBC) and to evaluate their association with clinicopathological features of ductal carcinoma in situ (DCIS). METHODS: We performed miRNA microarray analyses to find differentially expressed miRNAs between DCIS and IBC in a test set, and validated expression levels of selected miRNAs using a different set of tumors. Finally, we evaluated the relationship between clinicopathological features and the expression of selected miRNAs in DCIS samples. RESULTS: We found that miR-145-5p, miR-205-5p and miR-451a are significantly down-regulated in IBC compared to DCIS in the whole group, and in the estrogen receptor (ER)-positive and ER-negative subgroups. In a validation set, miR-145, miR-205, and miR-451 also showed lower expression levels in IBC than in DCIS, irrespective of ER status. Moreover, their expression levels were significantly lower in the invasive component compared to the in situ component within same tumors. MiR-145, miR-205 and miR-451 commonly showed lower expression levels in DCIS with positive HER2 status and high Ki-67 proliferation index. Especially, miR-145 and miR-205 showed lower expression levels in DCIS with microinvasion, compared to pure DCIS. In addition, lower miR-205 expression level was associated with high nuclear grade, comedo type necrosis, and hormone receptor negativity. CONCLUSIONS: Our study showed that miR-145, miR-205 and miR-451 expression decreased in IBC compared to DCIS, and their expression levels were low in DCIS with high-risk features for progression, implying their contributions in the progression of DCIS to invasive carcinoma as tumor suppressors.

Expression of HLA class I is associated with immune cell infiltration and patient outcome in breast cancer.

Downregulation of human leukocyte antigen (HLA) class I is one mechanism of escaping anti-tumor immunity by tumor cells. This study was conducted to compare HLA class I expression in ductal carcinoma in situ (DCIS) and invasive breast carcinoma (IBC) and to evaluate its association with immune cell infiltration of the tumors and clinical outcome of the patients. A total of 830 cases comprising 288 DCIS and 542 IBC were included in this study. Immunohistochemistry for HLA class I expression was performed using HLA-ABC in tissue microarrays and was analyzed in relation to clinicopathologic characteristics of tumors and infiltration of CD4+, CD8+, and FOXP3+ tumor-infiltrating lymphocyte (TIL) subsets and PD-L1+ immune cells. As a whole, there was no difference in HLA class I expression between DCIS and IBC when dichotomized into high or low expression. However, in the HR-negative group, a high level of HLA class I expression was more frequent in IBC than DCIS. On the contrary, in the HR-positive group, a complete loss of HLA class I expression was more frequently observed in IBC than DCIS. High HLA class I expression level was generally associated with aggressive clinicopathologic features of IBC and was associated with high CD4+, CD8+, and FOXP3+ TIL and PD-L1+ immune cell infiltration in both DCIS and IBC. In survival analyses, HLA class I expression was not associated with clinical outcome in DCIS and IBC as a whole; however, low HLA class I expression was associated with poor clinical outcome in HR-negative IBC, especially in triple-negative subtype. In conclusion, this study showed that HLA class I expression increased in association with increased immune cell infiltration during in situ to invasive transition of HR-negative breast cancer, and HLA class I down-regulation had a prognostic value in HR-negative breast cancer.

Role of CXCL10 in the progression of in situ to invasive carcinoma of the breast.

Tumor immune microenvironment plays a crucial role in tumor progression. We performed immune profiling to compare immune-related gene expression between ductal carcinoma in situ (DCIS) and invasive carcinoma of the breast using nCounter PanCancer immune Profiling Panel and found that CXCL10 was the most significant gene that had the highest difference in expression between them. Effect of CXCL10 on breast cancer cell proliferation and invasion was examined in vitro, and expression of CXCL10 and its relationship with immune cell infiltration was assessed in breast cancer samples. CXCL10 induced cell proliferation, migration and epithelial-mesenchymal transition in MCF-7 and MDA-MB-231 breast cancer cell lines. We confirmed that CXCL10 mRNA expression was significantly higher in invasive carcinoma than in DCIS, especially in hormone receptor (HR)-negative tumors using a validation set. CXCL10 mRNA expression showed a positive correlation with tumor infiltrating lymphocyte (TIL) density in both DCIS and invasive carcinoma; CXCL10-positive tumors generally showed higher infiltration of CD8+ and FOXP3+TILs as well as PD-L1+ immune cells compared to CXCL10-negative tumors, albeit with different patterns according to HR status. In conclusion, our study showed that CXCL10 promotes tumor cell proliferation, invasion, and immune cell infiltration, implying its contribution in the progression of DCIS to invasive carcinoma of the breast.

Aggregation of cohorts for histopathological diagnosis with deep morphological analysis.

There have been substantial efforts in using deep learning (DL) to diagnose cancer from digital images of pathology slides. Existing algorithms typically operate by training deep neural networks either specialized in specific cohorts or an aggregate of all cohorts when there are only a few images available for the target cohort. A trade-off between decreasing the number of models and their cancer detection performance was evident in our experiments with The Cancer Genomic Atlas dataset, with the former approach achieving higher performance at the cost of having to acquire large datasets from the cohort of interest. Constructing annotated datasets for individual cohorts is extremely time-consuming, with the acquisition cost of such datasets growing linearly with the number of cohorts. Another issue associated with developing cohort-specific models is the difficulty of maintenance: all cohort-specific models may need to be adjusted when a new DL algorithm is to be used, where training even a single model may require a non-negligible amount of computation, or when more data is added to some cohorts. In resolving the sub-optimal behavior of a universal cancer detection model trained on an aggregate of cohorts, we investigated how cohorts can be grouped to augment a dataset without increasing the number of models linearly with the number of cohorts. This study introduces several metrics which measure the morphological similarities between cohort pairs and demonstrates how the metrics can be used to control the trade-off between performance and the number of models.

Prognostic implications of regression of metastatic axillary lymph nodes after neoadjuvant chemotherapy in patients with breast cancer.

Prognostic implications of therapeutic response of metastatic lymph nodes (LNs) to neoadjuvant chemotherapy (NAC) remain unclear in patients with breast cancer. We aimed to evaluate the prognostic value of axillary LN regression after NAC in locally-advanced breast cancer patients. Therapeutic response of the LNs was evaluated in 563 breast cancer patients and classified into four grades according to the regression pattern. Initial pathologic N stage was estimated from the sum of the metastatic LNs and those with complete regression. In survival analyses, LN regression grade, pathologic N stage after NAC, and presumed initial pathologic N stage stratified clinical outcome of the patients in the whole group, in both ER-positive and ER-negative subgroups, and in those with residual breast disease. On multivariate analysis, LN regression grade and presumed initial pathologic N stage were revealed as independent prognostic factors. The number of completely-responsive LNs and the ratio of non-responsive LNs also revealed a prognostic value. In conclusion, regression grade of axillary LNs and presumed initial pathologic N stage have prognostic values in breast cancer patients who receive NAC. Thus, regression of axillary LNs should be evaluated and included in pathologic reporting of post-NAC resection specimens.

A Prospective Validation and Observer Performance Study of a Deep Learning Algorithm for Pathologic Diagnosis of Gastric Tumors in Endoscopic Biopsies.

PURPOSE: Gastric cancer remains the leading cause of cancer-related deaths in Northeast Asia. Population-based endoscopic screenings in the region have yielded successful results in early detection of gastric tumors. Endoscopic screening rates are continuously increasing, and there is a need for an automatic computerized diagnostic system to reduce the diagnostic burden. In this study, we developed an algorithm to classify gastric epithelial tumors automatically and assessed its performance in a large series of gastric biopsies and its benefits as an assistance tool. EXPERIMENTAL DESIGN: Using 2,434 whole-slide images, we developed an algorithm based on convolutional neural networks to classify a gastric biopsy image into one of three categories: negative for dysplasia (NFD), tubular adenoma, or carcinoma. The performance of the algorithm was evaluated by using 7,440 biopsy specimens collected prospectively. The impact of algorithm-assisted diagnosis was assessed by six pathologists using 150 gastric biopsy cases. RESULTS: Diagnostic performance evaluated by the AUROC curve in the prospective study was 0.9790 for two-tier classification: negative (NFD) versus positive (all cases except NFD). When limited to epithelial tumors, the sensitivity and specificity were 1.000 and 0.9749. Algorithm-assisted digital image viewer (DV) resulted in 47% reduction in review time per image compared with DV only and 58% decrease to microscopy. CONCLUSIONS: Our algorithm has demonstrated high accuracy in classifying epithelial tumors and its benefits as an assistance tool, which can serve as a potential screening aid system in diagnosing gastric biopsy specimens.

Changes and prognostic values of tumor-infiltrating lymphocyte subsets after primary systemic therapy in breast cancer.

Tumor-infiltrating lymphocyte (TIL) levels have prognostic and predictive values in treatment-naïve breast cancers. However, there have been controversies regarding TIL subset changes and their clinical implications in post-treatment breast cancers. This study aimed to explore change and prognostic significance of TIL subset infiltration after primary systemic therapy (PST) in breast cancer. One-hundred-fifty-five patients who had residual disease after anthracycline- or anthracycline plus taxane-based PST were included. The quantities of intratumoral and stromal TIL subsets (CD8+, CD4+, and FOXP3+ TILs) in pre- and post-PST breast cancer samples, as well as changes between them, were analyzed along with their correlations with clinicopathologic features and outcome of patients. As a whole, intratumoral CD8+ and CD4+ TILs increased after PST while stromal TILs decreased. Both intratumoral and stromal FOXP3+ TILs decreased after PST. The chemo-sensitive group [residual cancer burden (RCB) class I and II] showed the same pattern of change in intratumoral CD8+ TILs as the whole group, whereas the chemo-resistant group (RCB class III) showed no significant change in intratumoral CD8+ TIL infiltration after PST. Survival analyses for each TIL subset as well as their ratios revealed that high levels of intratumoral, stromal, and total CD8+ TIL infiltration after PST were independent predictors of longer patient survival. In subgroup analyses, CD8+ TIL infiltration after PST revealed prognostic significance in the chemo-resistant group but not in the chemo-sensitive group. In conclusion, infiltration of CD8+, CD4+, and FOXP3+ TIL changed after PST in the intratumoral and stromal compartments. Especially, increase of intratumoral CD8+ TILs was associated with chemo-responsiveness. Moreover, CD8+ TIL status in residual tumors after PST may be used as a potential prognostic marker in breast cancer patients who receive PST and provide additional prognostic information to chemo-resistant group.

The updated 2018 American Society of Clinical Oncology/College of American Pathologists guideline on human epidermal growth factor receptor 2 interpretation in breast cancer: comparison with previous guidelines and clinical significance of the proposed in situ hybridization groups.

The aim of the study was to evaluate the impact of the updated 2018 American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guideline on human epidermal growth factor receptor 2 (HER2) interpretation in breast cancer compared with that of the previous guidelines and also the significance of in situ hybridization (ISH) groups proposed by the updated guideline. HER2 ISH reports and immunohistochemistry (IHC) data from 1,348 invasive breast cancers diagnosed at a single institution were included in this study. HER2 IHC was reassessed using the 2018 guideline, and HER2 ISH status was determined by the 2007, 2013, and 2018 guidelines. When applying the updated guideline, most of the HER2 ISH-equivocal cases as per the previous guidelines were reclassified as ISH negative, and 0.8% of HER2 ISH-positive tumors as per the 2007 guideline and 2.5% of those as per the 2013 guideline were changed to ISH negative. Accordingly, the negative HER2 ISH results significantly increased in the 2018 guideline compared with the 2013 guideline. HER2 ISH-positive tumors in ISH group 3 (HER2/chromosome enumeration probe 17 [CEP17] ratio <2.0 and average HER2 copy number ≥6.0 per cell) were characterized by equivocal HER2 protein expression, CEP17 copy number gain, and low HER2 copy numbers compared with classic HER2 ISH-positive tumors in ISH group 1 (HER2/CEP17 ratio ≥2.0 and average HER2 copy number ≥4.0 per cell). HER2 ISH-negative tumors in ISH group 4 (HER2/CEP17 ratio <2.0 with average HER2 copy number ≥4.0 and < 6.0 per cell) revealed more aggressive clinicopathologic features and poorer clinical outcomes than those in ISH group 5 (HER2/CEP17 ratio <2.0 and average HER2 copy number <4.0 per cell), especially in the hormone receptor-positive subgroup. In conclusion, implementation of the updated 2018 ASCO/CAP guideline leads to a significant increase in HER2 ISH-negative results compared with the 2013 guideline, mainly via reclassification of the ISH-equivocal cases to ISH-negative ones. ISH groups proposed by the updated guideline provide additional information on the clinicopathologic characteristics of the tumors.

Changes in Biomarker Status in Metastatic Breast Cancer and Their Prognostic Value.

PURPOSE: There is cumulative evidence that changes in biomarker status occur frequently during the metastatic progression of breast cancer and affect treatment response. The purpose of this study was to evaluate the frequency of biomarker changes in metastatic breast cancer (MBC) and its impact on prognosis. METHODS: A total of 152 patients diagnosed with MBC at the time of initial diagnosis or during post-surgical follow-up were included. Changes in biomarker status in MBCs, their frequency according to various metastatic sites, tumor characteristics, and their association with patient survival were analyzed. RESULTS: Estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and Ki-67 status changed in 9 (6.0%), 40 (26.3%), 12 (7.9%), and 29 (19.1%) patients, respectively. ER, PR, and HER2 mainly showed positive to negative conversion, whereas Ki-67 changed mostly from a low to high index. There were no differences in the frequencies of biomarker changes according to the metastatic sites. As for ER and HER2, cases with negative conversion showed low expression levels in the primary tumor. Survival analyses indicated that a positive to negative conversion of ER was an independent poor prognostic factor in patients with primary ER-positive breast cancer. CONCLUSION: Changes in biomarker status are not rare, and usually occur in an unfavorable direction in breast cancer metastases. Negative conversion of ER status is a predictor of poor prognosis. Thus, it is beneficial to evaluate changes in biomarker status in MBC not only for the purpose of determining treatment options but also for prognostication of patients.

Clinical implications of changes in the diversity of c-MYC copy number variation after neoadjuvant chemotherapy in breast cancer.

Chemotherapy can alter the makeup of a tumor cell population by exerting selection pressure. We examined the change in Shannon index, a mathematical diversity measure used in ecology, for c-MYC copy number variation (CNV) after neoadjuvant chemotherapy and evaluated its clinical significance in breast cancer. Associations between Shannon indices for c-MYC CNV in pre- and post-neoadjuvant chemotherapy breast cancer samples and clinicopathologic features of tumors as well as patient survival were analyzed in 144 patients. A change in c-MYC amplification and copy number gain status was found in 14.3% and 33.6% with most cases showing positive to negative conversion. The chemo-sensitive group showed a significant decrease in Shannon index after neoadjuvant chemotherapy. However, there was no difference in diversity indices between pre- and post-neoadjuvant chemotherapy specimens in the chemo-resistant group. In survival analyses, high Shannon indices for c-MYC CNV in post-neoadjuvant chemotherapy samples as well as those in pre-neoadjuvant chemotherapy samples were revealed as independent prognostic factors for poor disease-free survival not only in the whole group but also in the chemo-resistant subgroup. These findings suggest that a change in Shannon index for c-MYC CNV after neoadjuvant chemotherapy reflects chemo-responsiveness and that Shannon indices after neoadjuvant chemotherapy have a prognostic value in breast cancer patients who receive neoadjuvant chemotherapy.