A Nationwide Study on HER2-low Breast Cancer in South Korea: Its Incidence of 2022 Real World Data and the Importance of Immunohistochemical Staining Protocols

Purpose

Notable effectiveness of trastuzumab deruxtecan (T-DXd) in patients with HER2-low advanced breast cancer (BC) has focused pathologists' attention. We studied the incidence and clinicopathologic characteristics of HER2-low BC, and the effects of immunohistochemistry (IHC) associated factors on HER2 IHC results.

Materials and Methods

The Breast Pathology Study Group of the Korean Society of Pathologists conducted a nationwide study using real-world data on HER2 status generated between January 2022 and December 2022. Information on HER2 IHC protocols at each participating institution was also collected.

Results

Total 11,416 patients from twenty-five institutions included in this study. Of these patients, 40.7% (range: 6.0%-76.3%) were classified as HER2-zero, 41.7% (range: 10.5%-69.1%) as HER2-low, and 17.5% (range: 6.7%-34.0%) as HER2-positive. HER2-low tumors were associated with positive ER and PR statuses (p<0.001 and p<0.001, respectively). Antigen retrieval times (≥ 36 min vs. < 36 min) and antibody incubation times (≥ 12 min vs. < 12 min) affected on the frequency of HER2 IHC 1+ BC at institutions using the PATHWAY HER2 (4B5) IHC assay and BenchMark XT or Ultra staining instruments. Furthermore, discordant results between core needle biopsy (CNB) and subsequent resection specimen HER2 statuses were observed in 24.1% (787/3259) of the patients.

Conclusion

The overall incidence of HER2-low BC in South Korea concurs with those reported in previously published studies. Significant inter-institutional differences in HER2 IHC protocols were observed, and it may have impact on HER2-low status. Thus, we recommend standardizing HER2 IHC conditions to ensure precise patient selection for targeted therapy.

Residual pure intralymphatic carcinoma component only (lymphovascular tumor emboli without invasive carcinoma) after neoadjuvant chemotherapy is associated with poor outcome: Not pathologic complete response

Residual pure intralymphatic carcinoma (PIC) component only after neoadjuvant chemotherapy (NAC) is lymphovascular tumor emboli without invasive carcinoma and extremely rare form of residual tumor after NAC. Although several studies have been published, the prognostic influence of residual PIC component only had not been fully evaluated. This study aims to evaluate the clinicopathologic features and the prognostic value of residual PIC component only. We reviewed the 251 patients with no residual invasive carcinoma in breast after NAC and found 12 patients with residual PIC component only after NAC. Five cases were triple negative, 6 were HER2 positive, and 1 was estrogen receptor positive and HER2 negative. The extent of PIC component ranged from 0.18 to 50.00 mm. The detailed microscopic PIC component findings did not significantly correlate with regional lymph node metastasis, local recurrence, or distant metastasis (p > 0.05). In multivariate survival analysis, the presence of lymph node metastasis and pretreatment ki-67 labeling index more than 50 % was statistically associated with greater risk of relapse [Cox proportional hazards ratio (HR) = 3.236, 95 % confidence interval (CI), 1.461-7.280, p = 0.004; HR = 3.046, 95 % CI, 1.421-6.529, p = 0.004, respectively) and residual PIC component only tended to be associated with greater risk of relapse (HR = 2.378, 95 % CI, 0.853-6.631; p = 0.098), but not reached to statistically significance. In patients without lymph node metastasis, the presence of residual PIC component only was associated with worse disease-free survival (p = 0.004). Although the number of published studies still limited, residual residual PIC component only after NAC is associated with poor outcome, and it should not be considered as pathological complete response.

Next-Generation Sequencing in Breast Cancer Patients: Real-World Data for Precision Medicine

PURPOSE

Breast cancer is one of the most common causes of cancer-related death in females. Numerous drug-targetable biomarkers and predictive biomarkers have been developed. Some researchers have expressed doubts about the need for next-generation sequencing (NGS) studies in daily practice. This study analyzed the results of NGS studies on breast cancer at a single institute and evaluated the real-world applications of NGS data to precision medicine for breast cancer.

MATERIALS AND METHODS

We retrospectively collected the results of NGS studies and analyzed the histopathologic features and genetic profiles of patients treated for breast cancer from 2010 to 2021. Seventy cases had data from CancerSCAN, a customized panel of 375 cancer-associated genes, and 110 cases had data from TruSight Oncology 500.

RESULTS

The most frequently detected single nucleotide variant was the TP53 mutation (123/180, 68.3%), followed by PIK3CA mutations (51/180, 28.3%). Estrogen receptor 1 (ESR1) mutation was detected in 11 patients (6.1%), of whom 10 had hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer, and two had no history of prior endocrine therapy. Based on their NGS study results, 13 patients (7.2%) received target therapy. Among them, four patients had a BRCA1 or BRCA2 germline mutation, and nine patients had a PIK3CA mutation.

CONCLUSION

NGS can provide information about predictive biomarkers and drug-targetable biomarkers that can enable treatment and participation in clinical trials based on precision medicine. Further studies should be conducted to excavate novel drug-targetable biomarkers and develop additional target therapies.

A Retrospective Exploratory Analysis for Serum Extracellular Vesicles Reveals APRIL (TNFSF13), CXCL13, and VEGF-A as Prognostic Biomarkers for Neoadjuvant Chemotherapy in Triple-Negative Breast Cancer

Neoadjuvant chemotherapy (NAC) is widely used as a standard treatment for early-stage triple-negative breast cancer (TNBC). While patients who achieve pathologic complete response (pCR) have a highly favorable outcome, patients who do not achieve pCR have variable prognoses. It is important to identify patients who are most likely to have poor survival outcomes to identify candidates for more aggressive therapeutic approaches after NAC. Many studies have demonstrated that cytokines and growth factors packaged into extracellular vesicles (EVs) have an essential role in tumor progression and drug resistance. In this study, we examined the role of serum-derived EV-associated cytokines as prognostic biomarkers for long-term outcomes in patients who underwent anthracycline-taxane-based NAC. We isolated extracellular vesicles from the serum of 190 TNBC patients who underwent NAC between 2015 and 2018 at Samsung Medical Center. EV-associated cytokine concentrations were measured with ProcartaPlex Immune Monitoring 65-plex panels. The prognostic value of EV-associated cytokines was studied. We found that patients with high EV_APRIL, EV_CXCL13, and EV_VEGF-A levels had shorter overall survival (OS). We further evaluated the role of these selected biomarkers as prognostic factors in patients with residual disease (RD) after NAC. Even in patients with RD, high levels of EV_APRIL, EV_CXCL13, and EV_VEGF-A were correlated with poor OS. In all subgroup analyses, EV_CXCL13 overexpression was significantly associated with poor overall survival. Moreover, multivariate analysis indicated that a high level of EV_CXCL13 was an independent predictor of poor OS. Correlation analysis between biomarker levels in EVs and serum showed that EV_VEGF-A positively correlated with soluble VEGF-A but not CXCL13. An elevated level of soluble VEGF-A was also associated with poor OS. These findings suggest that EV_APRIL, EV_CXCL13, and EV_VEGF-A may be useful in identifying TNBC patients at risk of poor survival outcomes after NAC.

Genomic characteristics of triple negative apocrine carcinoma: a comparison to triple negative breast cancer

Apocrine carcinoma is a rare breast cancer subtype. As such, the genomic characteristics of apocrine carcinoma with triple negative immunohistochemical results (TNAC), which has been treated as triple negative breast cancer (TNBC), have not been revealed. In this study, we evaluated the genomic characteristics of TNAC compared to TNBC with low Ki-67 (LK-TNBC). In the genetic analysis of 73 TNACs and 32 LK-TNBCs, the most frequently mutated driver gene in TNAC was TP53 (16/56, 28.6%), followed by PIK3CA (9/56, 16.1%), ZNF717 (8/56, 14.3%), and PIK3R1 (6/56, 10.71%). Mutational signature analysis showed enrichment of defective DNA mismatch repair (MMR)-related signatures (SBS6 and SBS21) and the SBS5 signature in TNAC, whereas an APOBEC activity-associated mutational signature (SBS13) was more prominent in LK-TNBC (Student's t test, p < 0.05). In intrinsic subtyping, 38.4% of TNACs were classified as luminal A, 27.4% as luminal B, 26.0% as HER2-enriched (HER2-E), 2.7% as basal, and 5.5% as normal-like. The basal subtype was the most dominant subtype (43.8%) in LK-TNBC (p < 0.001), followed by luminal B (21.9%), HER2-E (21.9%), and luminal A (12.5%). In the survival analysis, TNAC had a five-year disease-free survival (DFS) rate of 92.2% compared to 59.1% for LK-TNBC (P = 0.001) and a five-year overall survival (OS) rate of 95.3% compared to 74.6% for LK-TNBC (P = 0.0099). TNAC has different genetic characteristics and better survival outcomes than LK-TNBC. In particular, normal-like and luminal A subtypes in TNAC have much better DFS and OS than other intrinsic subtypes. Our findings are expected to impact medical practice for patients diagnosed with TNAC.

Lymphocyte-activating gene 3 expression in tumor cells predicts immune checkpoint inhibitor response in triple negative breast cancer

Introduction

Immune checkpoint inhibitor (ICI) is one of the standard treatment strategies in triple negative breast cancer (TNBC). However, the benefit of ICI with chemotherapy is limited in metastatic TNBC. In this study, we evaluated the effect of PD-L1 and LAG-3 expression on tissue microenvironment of mTNBC treated with ICI.

Methods

We reviewed representative formalin-fixed paraffin embedded specimens from metastatic or archival tumor tissues of TNBCs who treated with PD-1/PD-L1 inhibitors in metastatic setting. We used the Opal multiplex Detection kit with six antibodies (anti-PD-L1, anti-LAG-3, anti-CD68, anti-panCK, anti-CD8, anti-CD107a/LAMP antibody).

Results

We evaluated the association between LAG-3+cells and survival outcome regarding CK expression. Stromal LAG-3+/CK+ and LAG-3+/CK- cells were not associated with ICI-progression free survival(PFS) (P=0.16). However, LAG-3+ cell distributions in the tumor area impacted on ICI-PFS. A high density of LAG-3+CK+ cells was associated with shorter ICI-PFS compared with low densities of both LAG-3+CK+ and LAG-3+CK- cells (1.9 vs. 3.5 months). In addition, a high density of LAG-3+CK- cells had a relatively longer ICI-PFS compared with other groups (P=0.01). In terms of total area, the pattern of densities of LAG-3+CK+ cells and LAG-3+CK- cells were similar to those in the tumor area In addition, ICI-PFS of LAG-3+CK- and LAG-3+CK+ cell densities in the total area was equal to that in the tumor area.

Discussion

In conclusion, our findings revealed tumor-intrinsic LAG-3 expression was the resistance mechanism toward PD-1/PD-L1 inhibitors in mTNBCs. Multivariate analysis also suggested that LAG-3 expression in tumor cells was an independent predictive biomarker.

Artificial intelligence (AI)–powered spatial analysis of tumor-infiltrating lymphocytes (TIL) for prediction of response to neoadjuvant chemotherapy (NAC) in triple-negative breast cancer (TNBC)

595

Background: Stromal TIL are a well-recognized prognostic and predictive biomarker in breast cancer. There is a need for tools assisting visual assessment of TIL, to improve reproducibility as well as for convenience. This study aims to assess the clinical significance of AI-powered spatial TIL analysis in the prediction of pathologic complete response (pCR) after NAC in TNBC patients. Methods: H&E stained slides and clinical outcomes data were obtained from stage I – III TNBC patients treated with NAC in two centers in Korea. For spatial TIL analysis, we used Lunit SCOPE IO, an AI-powered H&E Whole-Slide Image (WSI) analyzer, which identifies and quantifies TIL within the cancer or stroma area. Lunit SCOPE IO was developed with a 13.5 x 109 micrometer2 area and 6.2 x 106 TIL from 17,849 H&E WSI of multiple cancer types, annotated by 104 board-certified pathologists. iTIL score and sTIL score were defined as area occupied by TIL in the intratumoral area (%) and the surrounding stroma (%), respectively. Immune phenotype (IP) of each slide was defined from spatial TIL calculation, as inflamed (high TIL density in tumor area), immune-excluded (high TIL density in stroma), or desert (low TIL density overall). Results: A total of 954 TNBC patients treated from 2006 to 2019 were included in this analysis. pCR (ypT0N0) was confirmed in 261 (27.4%) patients. The neoadjuvant regimens used were mostly anthracycline (97.8%) and taxane (75.1%) -based, with 116 (12.1%) patients receiving additional platinum and 41 (4.3%) patients treated as part of immune checkpoint inhibitor or PARP inhibitor clinical trials. The median iTIL score and sTIL score were 4.3% (IQR 3.2 – 5.8) and 8.1% (IQR 6.3 – 13.4), respectively. The mean iTIL score was significantly higher in patients who achieved pCR after NAC (5.8% vs. 4.5%, p < 0.001), and a similar difference was observed with sTIL score (12.1%.1 vs. 9.4%, p < 0.001). iTIL score was found to remain as an independent predictor of pCR along with cT stage and Ki-67 in the multivariable analysis (adjusted odds ratio 1.211 (95% CI 1.125 – 1.304) per 1 point (%) change in the score, p <0.001). By IP groups, 291 (30.5%) patients were classified as inflamed, 502 (52.6%) as excluded, and 161 (16.9%) as desert phenotype. The patients with inflamed phenotype were more likely to achieve pCR (44.7%) than other phenotypes (19.8%, p < 0.001). Conclusions: AI-powered spatial TIL analysis could assess TIL densities in the cancer area and surrounding stroma of TNBC, and TIL density scores and IP classification could predict pCR after NAC.

Histologic analysis according to HER2 gene status in HER2 2 + invasive breast cancer: a study of 280 cases comparing ASCO/CAP 2013 and 2018 guideline recommendations

The American Society of Clinical Oncology and College of American Pathologists guidelines for HER2 testing in breast cancer (BC) have been updated with more stringent criteria regarding immunohistochemistry (IHC) 2 + interpretation. The aim of our study was to determine HER2 status in IHC 2 + cases based on 2013 and 2018 guidelines and to investigate specific histologic characteristics that might predict HER2 status in tumors with equivocal IHC staining. Two hundred eighty BC cases reported as IHC 2 + and 24 cases reported as non-IHC 2 + were reviewed with 12 histologic characteristics. Of the IHC 2 + cases based on 2013 guideline, 21% were reclassified to IHC 1 + when applying the 2018 guidelines. Consequently, it led to an 8% increase of HER2 amplification rate in 2018 IHC 2 + group. Seven characteristics were significantly associated with prediction of HER2 amplification in IHC 2 + BCs, including high tumor-infiltrating lymphocytes (TILs), distinct cellular membrane, no apical snout, large nuclear size, nuclear size variation, high nuclear grade, and tubule formation < 10%. Using these criteria, the presence of four or more characteristics significantly indicates HER2 amplification. Moreover, four characteristics among them, including high TILs, distinct cellular membrane, nuclear size variation, and high nuclear grade, were also associated with HER2 amplification in non-IHC 2 + cases, demonstrating their predictive value as complements to IHC. In conclusion, we provide specific morphologic features that will improve pathologist performance in identifying more HER2-positive BCs. We further suggest an algorithm for trastuzumab therapy decisions using a combination of histomorphologic evaluation and the updated 2018 guidelines.

Ductal carcinoma in situ: a risk prediction model for the underestimation of invasive breast cancer

Patients with a biopsy diagnosis of ductal carcinoma in situ (DCIS) may be diagnosed with invasive breast cancer after excision. We evaluated the preoperative clinical and imaging predictors of DCIS that were associated with an upgrade to invasive carcinoma on final pathology and also compared the diagnostic performance of various statistical models. We reviewed the medical records; including mammography, ultrasound (US), and magnetic resonance imaging (MRI) findings; of 644 patients who were preoperatively diagnosed with DCIS and who underwent surgery between January 2012 and September 2018. Logistic regression and three machine learning methods were applied to predict DCIS underestimation. Among 644 DCIS biopsies, 161 (25%) underestimated invasive breast cancers. In multivariable analysis, suspicious axillary lymph nodes (LNs) on US (odds ratio [OR], 12.16; 95% confidence interval [CI], 4.94-29.95; P < 0.001) and high nuclear grade (OR, 1.90; 95% CI, 1.24-2.91; P = 0.003) were associated with underestimation. Cases with biopsy performed using vacuum-assisted biopsy (VAB) (OR, 0.42; 95% CI, 0.27-0.65; P < 0.001) and lesion size <2 cm on mammography (OR, 0.45; 95% CI, 0.22-0.90; P = 0.021) and MRI (OR, 0.29; 95% CI, 0.09-0.94; P = 0.037) were less likely to be upgraded. No significant differences in performance were observed between logistic regression and machine learning models. Our results suggest that biopsy device, high nuclear grade, presence of suspicious axillary LN on US, and lesion size on mammography or MRI were independent predictors of DCIS underestimation.

A multicenter study of interobserver variability in pathologic diagnosis of papillary breast lesions on core needle biopsy with WHO classification

BACKGROUND

Papillary breast lesions (PBLs) comprise diverse entities from benign and atypical lesions to malignant tumors. Although PBLs are characterized by a papillary growth pattern, it is challenging to achieve high diagnostic accuracy and reproducibility. Thus, we investigated the diagnostic reproducibility of PBLs in core needle biopsy (CNB) specimens with World Health Organization (WHO) classification.

METHODS

Diagnostic reproducibility was assessed using interobserver variability (kappa value, κ) and agreement rate in the pathologic diagnosis of 60 PBL cases on CNB among 20 breast pathologists affiliated with 20 medical institutions in Korea. This analysis was performed using hematoxylin and eosin (H&E) staining and immunohistochemical (IHC) staining for cytokeratin 5 (CK5) and p63. The pathologic diagnosis of PBLs was based on WHO classification, which was used to establish simple classifications (4-tier, 3-tier, and 2-tier).

RESULTS

On WHO classification, H&E staining exhibited 'fair agreement' (κ = 0.21) with a 47.0% agreement rate. Simple classifications presented improvement in interobserver variability and agreement rate. IHC staining increased the kappa value and agreement rate in all the classifications. Despite IHC staining, the encapsulated/solid papillary carcinoma (EPC/SPC) subgroup (κ = 0.16) exhibited lower agreement compared to the non-EPC/SPC subgroup (κ = 0.35) with WHO classification, which was similar to the results of any other classification systems.

CONCLUSIONS

Although the use of IHC staining for CK5 and p63 increased the diagnostic agreement of PBLs in CNB specimens, WHO classification exhibited a higher discordance rate compared to any other classifications. Therefore, this result warrants further intensive consensus studies to improve the diagnostic reproducibility of PBLs with WHO classification.

A multicenter study of interobserver variability in pathologic diagnosis of papillary breast lesions on core needle biopsy with WHO classification

Background

Papillary breast lesions (PBLs) comprise diverse entities from benign and atypical lesions to malignant tumors. Although PBLs are characterized by a papillary growth pattern, it is challenging to achieve high diagnostic accuracy and reproducibility. Thus, we investigated the diagnostic reproducibility of PBLs in core needle biopsy (CNB) specimens with World Health Organization (WHO) classification.

Methods

Diagnostic reproducibility was assessed using interobserver variability (kappa value, κ) and agreement rate in the pathologic diagnosis of 60 PBL cases on CNB among 20 breast pathologists affiliated with 20 medical institutions in Korea. This analysis was performed using hematoxylin and eosin (H&E) staining and immunohistochemical (IHC) staining for cytokeratin 5 (CK5) and p63. The pathologic diagnosis of PBLs was based on WHO classification, which was used to establish simple classifications (4-tier, 3-tier, and 2-tier).

Results

On WHO classification, H&E staining exhibited ‘fair agreement’ (κ = 0.21) with a 47.0% agreement rate. Simple classifications presented improvement in interobserver variability and agreement rate. IHC staining increased the kappa value and agreement rate in all the classifications. Despite IHC staining, the encapsulated/solid papillary carcinoma (EPC/SPC) subgroup (κ = 0.16) exhibited lower agreement compared to the non-EPC/SPC subgroup (κ = 0.35) with WHO classification, which was similar to the results of any other classification systems.

Conclusions

Although the use of IHC staining for CK5 and p63 increased the diagnostic agreement of PBLs in CNB specimens, WHO classification exhibited a higher discordance rate compared to any other classifications. Therefore, this result warrants further intensive consensus studies to improve the diagnostic reproducibility of PBLs with WHO classification.

Prediction of pathologic complete response to neoadjuvant chemotherapy using machine learning models in patients with breast cancer

BACKGROUND

The aim of this study was to develop a machine learning (ML) based model to accurately predict pathologic complete response (pCR) to neoadjuvant chemotherapy (NAC) using pretreatment clinical and pathological characteristics of electronic medical record (EMR) data in breast cancer (BC).

METHODS

The EMR data from patients diagnosed with early and locally advanced BC and who received NAC followed by curative surgery were reviewed. A total of 16 clinical and pathological characteristics was selected to develop ML model. We practiced six ML models using default settings for multivariate analysis with extracted variables.

RESULTS

In total, 2065 patients were included in this analysis. Overall, 30.6% (n = 632) of patients achieved pCR. Among six ML models, the LightGBM had the highest area under the curve (AUC) for pCR prediction. After hyper-parameter tuning with Bayesian optimization, AUC was 0.810. Performance of pCR prediction models in different histology-based subtypes was compared. The AUC was highest in HR+HER2- subgroup and lowest in HR-/HER2- subgroup (HR+/HER2- 0.841, HR+/HER2+ 0.716, HR-/HER2 0.753, HR-/HER2- 0.653).

CONCLUSIONS

A ML based pCR prediction model using pre-treatment clinical and pathological characteristics provided useful information to predict pCR during NAC. This prediction model would help to determine treatment strategy in patients with BC planned NAC.

Programmed Death Ligand 1 Immunohistochemistry in Triple-Negative Breast Cancer: Evaluation of Inter-Pathologist Concordance and Inter-Assay Variability

Purpose

The programmed death ligand 1 (PD-L1) SP142 assay with a 1% immune cell (IC) cutoff is approved for the selection of advanced triple-negative breast cancer (TNBC) patients for atezolizumab treatment. We aimed to evaluate the interobserver concordance of PD-L1 scoring and inter-assay variability of various PD-L1 assays in TNBC.

Methods

Thirty patients with primary TNBC were selected, and SP142, SP263, 22C3, and E1L3N assays were performed. PD-L1 staining in ICs and tumor cells (TCs) was scored by 10 pathologists who were blinded to the assay. The interobserver concordance among pathologists and the inter-assay variability of the four PD-L1 assays were analyzed. For SP142, the intraobserver concordance among the six pathologists was analyzed after training.

Results

The adjusted means of PD-L1 IC scoring ranged from 6.2% to 12.9% for the four assays; the intraclass correlations showed moderate (0.584–0.649) reader concordance. The PD-L1 IC scoring with a 1% cutoff resulted in identical scoring in 40.0%–66.7% of cases and a poor to moderate agreement (Fleiss κ statistic [FKS] = 0.345–0.534) for the four assays. The SP142 assay had the widest range of positive rate (56.5%–100.0%), lowest number of cases with identical scoring, and lowest FKS at 1% cutoff. Pairwise comparison of adjusted means showed significantly decreased PD-L1 staining in SP142 compared with the other assays in both ICs and TCs. As for the intraobserver concordance in the SP142 assay, the overall percent agreement was 87.8% with a 1% IC cutoff. After training, the proportion of cases with identical scoring at a 1% IC cutoff increased to 70.0%; the FKS also increased to 0.610.

Conclusion

The concordance of PD-L1 IC scoring among pathologists was low, at the 1% cutoff for the SP142 assay without training. SP142 showed the lowest PD-L1 expression in both IC and TC.

Lymphomatoid Granulomatosis Involving the Lung and Brain in a Child: A Case Report

Lymphomatoid granulomatosis (LG) is a rare B-cell type angiocentric lymphoproliferative disease that can progress to extranodal lymphoma with high mortality. It most commonly affects the lungs, although extrapulmonary systems, including the brain and skin, can also be involved. LG in pediatric patients has been very rarely reported in the literature with limited imaging features. Herein, we report a pediatric case of LG involving the lung and brain with characteristic imaging findings.

Distribution of tumor subtypes in bilateral breast cancer: Comparison between synchronous and metachronous cancer

AIM

This study was performed to evaluate patterns of breast cancer subtypes in Korean patients with synchronous (SBC) or metachronous bilateral breast cancer (MBC).

METHODS

We retrospectively reviewed records of 302 patients with SBC (n = 161) or MBC (n = 141) who received curative surgery at our hospital between 1995 and 2013. Expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) was determined by immunohistochemistry (IHC) staining. We categorized breast cancers into the following subtypes: ER+ or PR+, HER2- (i.e., luminalA); ER+ or PR+, HER2+ (i.e., luminalB HER2+); ER-, PR- and HER2+ (i.e., HER2-enriched); ER-, PR- and HER2- (i.e., triple negative, TN).

RESULTS

More patients with MBC were ≤40 years at the time of breast cancer diagnosis than patients with SBC (34.6% vs. 19.3%, P < 0.01). The proportion of subtypes in SBC and MBC were as follows: luminalA, 65.8% vs. 45.0%; luminalB, HER2+, 9.0% vs. 8.5%; HER2-enriched, 4.1% vs. 12.1%; and TN, 11.2% vs. 31.2%, respectively (P < 0.01). The 10-year overall survival rate in patients with SBC and MBC was 89.0% and 93.6%, respectively. The 10-year disease-free survival rate in patients with SBC and MBC was 79.6% and 80.9%, respectively. Locoregional recurrence was found in 2.5% of patients with SBC and 9.9% of patients with MBC. Distant metastasis occurred in 8.7% of patients with SBC and 4.9% of patients with MBC.

CONCLUSION

The distribution of breast cancer subtypes was different between SBC and MBC. TN-subtype was profoundly more frequent in MBC whereas luminal-subtype was most frequently found among SBC.

Accuracy and efficiency of an artificial intelligence tool when counting breast mitoses

BACKGROUND

The mitotic count in breast carcinoma is an important prognostic marker. Unfortunately substantial inter- and intra-laboratory variation exists when pathologists manually count mitotic figures. Artificial intelligence (AI) coupled with whole slide imaging offers a potential solution to this problem. The aim of this study was to accordingly critique an AI tool developed to quantify mitotic figures in whole slide images of invasive breast ductal carcinoma.

METHODS

A representative H&E slide from 320 breast invasive ductal carcinoma cases was scanned at 40x magnification. Ten expert pathologists from two academic medical centers labeled mitotic figures in whole slide images to train and validate an AI algorithm to detect and count mitoses. Thereafter, 24 readers of varying expertise were asked to count mitotic figures with and without AI support in 140 high-power fields derived from a separate dataset. Their accuracy and efficiency of performing these tasks were calculated and statistical comparisons performed.

RESULTS

For each experience level the accuracy, precision and sensitivity of counting mitoses by users improved with AI support. There were 21 readers (87.5%) that identified more mitoses using AI support and 13 reviewers (54.2%) that decreased the quantity of falsely flagged mitoses with AI. More time was spent on this task for most participants when not provided with AI support. AI assistance resulted in an overall time savings of 27.8%.

CONCLUSIONS

This study demonstrates that pathology end-users were more accurate and efficient at quantifying mitotic figures in digital images of invasive breast carcinoma with the aid of AI. Higher inter-pathologist agreement with AI assistance suggests that such algorithms can also help standardize practice. Not surprisingly, there is much enthusiasm in pathology regarding the prospect of using AI in routine practice to perform mundane tasks such as counting mitoses.

Primary Peritoneal High-grade Serous Carcinoma Misinterpreted as Metastatic Breast Carcinoma: A Rare Encounter in Peritoneal Fluid Cytology

BACKGROUND/AIM

Peritoneal fluid (PF) cytology is critical for distinguishing high-grade serous carcinoma (HGSC) from metastatic disease in patients with breast carcinoma who present with peritoneal carcinomatosis (PC).

CASE REPORT

A 50-year-old woman underwent surgery and adjuvant therapy for pT1N0 grade 2/2 luminal A breast carcinoma. Sixteen months postoperatively, palliative chemotherapy was administered following a pleural biopsy and diagnosis of metastatic carcinoma. The patient developed PC despite chemotherapy. PF cytology specimens suggested metastatic carcinoma. However, we observed a papillary cellular arrangement during the review of cytology slides. HGSC was confirmed by immunocytochemistry showing positive paired box 8 (PAX8) and Wilms' tumor 1 (WT1) expression and negative GATA-binding protein 3 expression.

CONCLUSION

In patients with breast carcinoma history, an awareness of characteristic cytomorphology of HGSC, including a papillary pattern with positive PAX8 and WT1 immunoreactivity, is essential to prevent the misdiagnosis of such cases and in ensuring accurate treatment and management.

Clinicopathologic characteristics of HER2-positive pure mucinous carcinoma of the breast

BACKGROUND

Pure mucinous carcinoma (PMC) is a rare type of breast cancer, estimated to represent 2% of invasive breast cancer. PMC is typically positive for estrogen receptors (ER) and progesterone receptors (PR) and negative for human epidermal growth factor receptor 2 (HER2). The clinicopathologic characteristics of HER2-positive PMC have not been investigated.

METHODS

Pathology archives were searched for PMC diagnosed from January 1999 to April 2018. Clinicopathologic data and microscopic findings were reviewed and compared between HER2-positive PMC and HER2-negative PMC. We also analyzed the differences in disease-free survival (DFS) and overall survival according to clinicopathologic parameters including HER2 status in overall PMC cases.

RESULTS

There were 21 HER2-positive cases (4.8%) in 438 PMCs. The average tumor size of HER2-positive PMC was 32.21 mm (± 26.55). Lymph node metastasis was present in seven cases. Compared to HER2-negative PMC, HER2-positive PMC presented with a more advanced T category (p < .001), more frequent lymph node metastasis (p = .009), and a higher nuclear and histologic grade (p < .001). Microscopically, signet ring cells were frequently observed in HER2-positive PMC (p < .001), whereas a micropapillary pattern was more frequent in HER2-negative PMC (p = .012). HER2-positive PMC was more frequently negative for ER (33.3% vs. 1.2%) and PR (28.6% vs. 7.2%) than HER2-negative PMC and showed a high Ki-67 labeling index. During follow-up, distant metastasis and recurrence developed in three HER2-positive PMC patients. Multivariate analysis revealed that only HER2-positivity and lymph node status were significantly associated with DFS.

CONCLUSIONS

Our results suggest that HER2-positive PMC is a more aggressive subgroup of PMC. HER2 positivity should be considered for adequate management of PMC.

Abstract 3144: Deep learning-based predictive biomarker for adjuvant chemotherapy in early-stage hormone receptor-positive breast cancer

Introduction: Predictive value of adjuvant chemotherapy for patients with early-stage hormone receptor-positive breast cancer has been suggested by 21-gene expression assay, although its cost-effectiveness has not been well-defined. We have developed the deep learning-based H&E image analyzer named Lunit SCOPE, identifying and quantifying various histologic components from H&E-stained whole slide images We hypothesized that cell proportions analyzed by Lunit SCOPE would be a potential prognostic and predictive biomarker of adjuvant chemotherapy in early-stage hormone receptor-positive breast cancer.

Method: We have collected clinical data and H&E slides from de-identified 2,915 early breast cancer patients in Samsung Medical Center, retrospectively. The 898 patients with hormone receptor-positive, T1b ~ T3 and N0 ~ N1mi have been selected to analyze the predictive value of adjuvant chemotherapy. Deep learning-based H&E image analyzer, Lunit SCOPE, has been trained by 1,191 H&E-stained whole slide images from another breast cancer patient cohort. In the whole slide image, biological and histological components such as cancer epithelium, cancer stroma, normal, fat, necrosis, lymphocyte, fibroblast, and other cells, have been annotated by over 10 pathologists. The outputs of Lunit SCOPE are the ratio of cancer epithelium, cancer stroma, normal, necrosis and fat in a whole slide image and intratumoral tumor infiltrating lymphocyte (TIL) and stromal TIL density. The recurrence score (RS) based on the output of Lunit SCOPE has been determined by using multivariate cox regression analysis for disease-free survival (DFS) in the patients without adjuvant chemotherapy.

Result: Recurrence score (RS) was proportional to the cancer stroma ratio and stromal TIL density, but inversely proportional to intratumoral TIL density. When the RS cutoff was 0.913, 21.3% (191 out of 898) of patients were classified as high risk group (RS &gt; cutoff). Among those without adjuvant chemotherapy, high risk group presented poor DFS (hazard ratio [HR] 4.23, 95% confidence interval [CI] 1.87-9.59, P = 1.73 x 10-4) and overall survival (OS, HR 4.95, 95% CI 1.39-17.6, P = 6.07 x 10-3) than the low risk group. Adjuvant chemotherapy did not prolong OS in patients with low risk group (HR 1.08, 95% CI 0.38-3.12, P = 0.885). However, interestingly, in those with high risk by Lunit SCOPE, adjuvant chemotherapy prolonged DFS (HR 0.35, 95% CI 0.15-0.86, P = 0.0161) and OS (HR 0.22, 95% CI 0.05-0.95, P = 0.0254), reflecting RS by Lunit SCOPE would be a significant predictive biomarker of adjuvant chemotherapy.

Conclusion: Deep learning-based H&E image analyzer, Lunit SCOPE, was possible to analyze the prognosis of breast cancer. Especially, only high risk patients of RS by Lunit SCOPE had survival benefit from adjuvant chemotherapy, which needs to be validated in clinical trials.

Citation Format: Soo Youn Cho, Eun Yoon Cho, Kyunghyun Paeng, Geunyoung Jung, Sarah Lee, Sang Yong Song. Deep learning-based predictive biomarker for adjuvant chemotherapy in early-stage hormone receptor-positive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3144.

Human Epidermal Growth Factor Receptor 2-positive Mucinous Carcinoma with Signet Ring Cell Differentiation, Which Showed Complete Response after Neoadjuvant Chemotherapy

Mucinous carcinoma (MC) is a rare subtype of breast cancer, which is composed of tumor cells floating in the abundant extracellular mucin. This form of cancer is usually estrogen receptor/progesterone receptor positive and human epidermal growth factor receptor 2 (HER2) negative. Here, we present a case of HER2-positive MC with an unusual signet ring cell differentiation. It is very rare that a breast tumor consists entirely of signet ring cells. The tumor showed pathologic complete response (pCR) after neoadjuvant chemotherapy with trastuzumab and pertuzumab. pCR of HER2-positive MC has rarely been described in literature. It is important to consider the biological heterogeneity of MCs for effective management.

Abstract P4-08-30: Prognostication of immune related gene expression in patients with triple negative breast cancer

Introduction: To date, the role of immunotherapy with check point inhibitors and/or vaccines in the treatment of breast cancer (BC) is still debating, and the main focus of immunotherapy in BC is on triple negative subtype as a target population in many ongoing clinical trials. Translational research into identifying predictive and prognostic immune biomarkers is of particular clinical relevance, but, there are currently no definite prognostic and predictive immune biomarkers in BC, especially in triple negative breast cancer(TNBC). We investigated the expression profiles of immune genes in patients with TNBC to identify the prognostic value of immune genes in search of clinical implications.

Methods : We investigated expression profiles of 770 pan-cancer immune related genes using the nCounter mRNA expression assay (NanoString®) from paraffin-embedded tumor tissues in 200 patients diagnosed as TNBC who received curative surgery at Samsung Medical Center from 2000 to 2004. We analyzed the relationship between stage adjusted level of gene expressions and patients' survival outcomes using Cox regression model.

Results: Of 770 genes, 186 genes were selected from univariate analysis with clinical stage adjustment. In multivariate analysis using Cox regression, expressions of CD1B, CD45, CD53, CT45A1, GTF3C1, IL11RA, IL1RN, LRRN3, MAPK1, NEFL, PRKCE, SPACA3 and RANKL were associated with distant recurrence free survival (p&lt;0.05, respectively). Among these 13 genes, expression of MAPK1, NEFL, CD45, SPACA3 and RANKL were correlated with favorable outcome in terms of distant recurrence free survival (p&lt;0.05, respectively). In terms of overall survival, C3, IL1RL1, IL1RN, IL7 and PRKCE were associated with poor prognosis (p&lt;0.05, respectively) and expression of SAA1 CXCL9 and RANKL resulted in favorable outcome (p&lt;0.05, respectively).

Table 1ParameterParameter EstimateStandard Errorp-valueHazard Ratio95% Confidence Interval(a) distant recurrence free survival     Stage2.487350.680570.000312.0293.169, 45.661CD1B1.141910.2753&lt;.00013.1331.826, 5.374CD531.531650.34851&lt;.00014.6262.336, 9.159CT45A10.426110.134210.00151.5311.177, 1.992GTF3C11.193110.579720.03963.2971.059, 10.271IL11RA1.671120.461750.00035.3182.151, 13.146IL1RN0.980280.24657&lt;.00012.6651.644, 4.321LRRN31.424170.28742&lt;.00014.1542.365, 7.297MAPK1-0.542740.258240.03560.5810.35, 0.964NEFL-1.12170.335610.00080.3260.169, 0.629PRKCE2.378340.49659&lt;.000110.7874.076, 28.549CD45-2.736780.43154&lt;.00010.0650.028, 0.151SPACA3-0.745930.272270.00610.4740.278, 0.809RANKL-1.288920.2976&lt;.00010.2760.154, 0.494(b) overall survival     Stage1.359280.497810.00633.8931.468, 10.329C30.329830.150350.02831.3911.036, 1.867CXCL9-0.379190.100680.00020.6840.562, 0.834IL1RL10.679360.262940.00981.9731.178, 3.303IL1RN0.437130.172370.01121.5481.104, 2.171IL70.507280.206250.01391.6611.109, 2.488PRKCE0.835340.272910.00222.3061.35, 3.936SAA1-0.564250.13449&lt;.00010.5690.437, 0.74RANKL-0.604990.234510.00990.5460.345, 0.865

Conclusion: High expression of IL1RN, PRKCE were associated with short distant recurrence free survival and overall survival in patients with TNBCs who received curative surgery. In contrast, RANKL expression resulted in prolonged distant recurrence free survival and overall survival.

Citation Format: Kim J-Y, Jung HH, Lim JE, Cho EY, Lee SK, Yu JH, Lee JE, Kim SW, Nam SJ, Park YH, Ahn JS, Im Y-H. Prognostication of immune related gene expression in patients with triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-08-30.

Metformin and tenovin-6 synergistically induces apoptosis through LKB1-independent SIRT1 down-regulation in non-small cell lung cancer cells

Sirtuin 1 (SIRT1) is known to play a role in a variety of tumorigenesis processes by deacetylating histone and non‐histone proteins; however, antitumour effects by suppressing SIRT1 activity in non‐small cell lung cancer (NSCLC) remain unclear. This study was designed to scrutinize clinicopathological significance of SIRT1 in NSCLC and investigate effects of metformin on SIRT1 inhibition. This study also evaluated new possibilities of drug combination using a SIRT1 inhibitor, tenovin‐6, in NSCLC cell lines. It was found that SIRT1 was overexpressed in 300 (62%) of 485 formalin‐fixed paraffin‐embedded NSCLC tissues. Its overexpression was significantly associated with reduced overall survival and poor recurrence‐free survival after adjusted for histology and pathologic stage. Thus, suppression of SIRT1 expression may be a reasonable therapeutic strategy for NSCLC. Metformin in combination with tenovin‐6 was found to be more effective in inhibiting cell growth than either agent alone in NSCLC cell lines with different liver kinase B1 (LKB1) status. In addition, metformin and tenovin‐6 synergistically suppressed SIRT1 expression in NSCLC cells regardless of LKB1 status. The marked reduction in SIRT1 expression by combination of metformin and tenovin‐6 increased acetylation of p53 at lysine 382 and enhanced p53 stability in LKB1‐deficient A549 cells. The combination suppressed SIRT1 promoter activity more effectively than either agent alone by up‐regulating hypermethylation in cancer 1 (HIC1) binding at SIRT1 promoter. Also, suppressed SIRT1 expression by the combination synergistically induced caspase‐3‐dependent apoptosis. The study concluded that metformin with tenovin‐6 may enhance antitumour effects through LKB1‐independent SIRT1 down‐regulation in NSCLC cells.

Clinicopathological and Molecular Characteristics of Mammary Adenoid Cystic Carcinoma With Adipocytic Differentiation With Emphasis on the Identification of a Novel BRAF Mutation

BACKGROUND/AIM

Adenoid cystic carcinoma accounts for fewer than 1% of all breast malignancies. Herein, we describe the clinicopathological characteristics and immunophenotype of mammary adenoid cystic carcinoma that exhibited adipocytic differentiation. Furthermore, we aimed to identify mutations potentially associated with this rare tumor.

CASE REPORT

A 52-year-old woman was referred to our Institution after detection of an incidental breast mass. The resected breast specimen contained a well-circumscribed, firm mass surrounded by ill-defined, soft, yellow bulging nodules and measured 2.5 cm in the greatest dimension. The surgically-resected breast lesion was subjected to pathological examination and immunohistochemical staining. Next-generation sequencing was also carried out on an Ion Torrent Personal Genome Machine, using Ion AmpliSeq Cancer Hotspot Panel v2. Histologically, the tumor had two components: a central area of complex glandular proliferation with solid and cribriform architectures and a peripheral area showing adipocytic differentiation with spindle cell proliferation. Immunohistochemical staining revealed positive immunoreactivity for cytokeratin 5/6, epidermal growth factor receptor, and smooth muscle actin in both the central and peripheral areas. Next-generation sequencing-based genetic analysis identified a homozygous missense mutation (NM_004333.4:c.1742A>G; p.N581S) in the v-Raf murine sarcoma viral oncogene homolog B (BRAF) gene.

CONCLUSION

We report the first case, as far as we are aware, of primary mammary adenoid cystic carcinoma with adipocytic differentiation. A novel missense mutation in BRAF was detected. The potential response to BRAF inhibitors in the presence of this mutation remains a matter for further studies.

PIK3CA Mutations and Neoadjuvant Therapy Outcome in Patients with Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer: A Sequential Analysis

Purpose

PIK3CA mutation is considered to be a possible cause for resistance to neoadjuvant chemotherapy (NAC) in human epidermal growth factor receptor 2 (HER2)-positive breast cancer. We investigated the association between PIK3CA mutations and the outcome of NAC in HER2-positive breast cancers.

Methods

A total of 100 HER2-positive breast cancer patients who had undergone NAC and surgery between 2004 and 2016 were examined. Mutation status was sequentially assessed in pre-NAC, post-NAC, and recurrent specimens taken from these patients.

Results

PIK3CA mutations were identified in the sequential specimens of 17 patients (17.0%). These 17 patients experienced shorter disease-free survival (DFS) than the rest of the patients (58.3 months vs. 119.3 months, p=0.020); however, there was no significant difference in pathologic complete response (pCR) and overall survival (OS) (pCR, 17.6% vs. 33.7%, p=0.191; OS, 84.5 months vs. 118.0 months, p=0.984). While there was no difference in pCR between the wild-type and mutant PIK3CA groups in pre-NAC specimens (25.0% vs. 31.8%, p=0.199), PIK3CA mutations correlated with lower pCR in post-NAC specimens (0.0% vs. 24.3%, p<0.001). Multivariate analysis revealed significantly worse DFS in the mutant PIK3CA group than in the wild-type group (hazard ratio, 3.540; 95% confidence interval, 1.001–12.589; p=0.050). Moreover, the DFS curves of the change of PIK3CA mutation status in sequential specimens were significantly different (p=0.016).

Conclusion

PIK3CA mutation in HER2-positive breast cancer was correlated with a lower pCR rate and shorter DFS. These results suggest that PIK3CA mutation is a prognostic marker for NAC in HER2-positive breast cancer, especially in post-NAC specimens.

The Prognostic Impact of Synchronous Ipsilateral Multiple Breast Cancer: Survival Outcomes according to the Eighth American Joint Committee on Cancer Staging and Molecular Subtype

BACKGROUND

In the current American Joint Committee on Cancer staging system of breast cancer, only tumor size determines T-category regardless of whether the tumor is single or multiple. This study evaluated if tumor multiplicity has prognostic value and can be used to subclassify breast cancer.

METHODS

We included 5,758 patients with invasive breast cancer who underwent surgery at Samsung Medical Center, Seoul, Korea, from 1995 to 2012.

RESULTS

Patients were divided into two groups according to multiplicity (single, n = 4,744; multiple, n = 1,014). Statistically significant differences in lymph node involvement and lymphatic invasion were found between the two groups (p < .001). Patients with multiple masses tended to have luminal A molecular subtype (p < .001). On Kaplan-Meier survival analysis, patients with multiple masses had significantly poorer disease-free survival (DFS) (p = .016). The prognostic significance of multiplicity was seen in patients with anatomic staging group I and prognostic staging group IA (p = .019 and p = .032, respectively). When targeting patients with T1-2 N0 M0, hormone receptor-positive, and human epidermal growth factor receptor 2 (HER2)-negative cancer, Kaplan-Meier survival analysis also revealed significantly reduced DFS with multiple cancer (p = .031). The multivariate analysis indicated that multiplicity was independently correlated with worse DFS (hazard ratio, 1.23; 95% confidence interval, 1.03 to 1.47; p = .025). The results of this study indicate that tumor multiplicity is frequently found in luminal A subtype, is associated with frequent lymph node metastasis, and is correlated with worse DFS.

CONCLUSIONS

Tumor multiplicity has prognostic value and could be used to subclassify invasive breast cancer at early stages. Adjuvant chemotherapy would be necessary for multiple masses of T1-2 N0 M0, hormone-receptor-positive, and HER2-negative cancer.

TFE3-Expressing Perivascular Epithelioid Cell Tumor of the Breast

Perivascular epithelioid cell tumor (PEComa) is a very rare mesenchymal tumor with a distinctive morphology and immunophenotype. PEComas usually harbor TSC2 alterations, although TFE3 translocations, which occur in MiT family translocation renal cell carcinoma and alveolar soft part sarcoma, are also possible. We recently experienced a case of PEComa with TFE3 expression arising in the breast. An 18-year-old female patient presented with a right breast mass. Histologically, the tumor consisted of epithelioid cells with alveolar structure and showed a diffuse strong expression of HMB45 and TFE3. TSC2 was preserved. Melan A and smooth muscle actin were negative. To our knowledge, this is the first Korean case of PEComa of the breast that intriguingly presented with TFE3 expression.

Risk Factors for Dropout From the Liver Transplant Waiting List of Hepatocellular Carcinoma Patients Under Locoregional Treatment

BACKGROUND

In new organ allocation policy, patients with hepatocellular carcinoma (HCC) experience a 6-month delay in being granted Model for End-Stage Liver Disease exception points. However, it may not be fair for patients at risk of early progression of HCC.

METHODS

All patients who were diagnosed as United Network for Organ Sharing (UNOS) stage 1 or 2 of HCC between January 2004 and December 2012 were included. Patients who received surgical resection or liver transplant (LT) as a primary treatment and who did not receive any treatment for HCC were excluded. Patients with baseline Model for End-Stage Liver Disease score ≥22 were also excluded because they have a higher chance of receiving LT. Patients who developed extrahepatic progression within 1 year were considered as high-risk for early recurrence after LT.

RESULTS

A total of 586 patients were included. Mean (SD) age was 59.9 (10.3) years and 409 patients (69.8%) were men. The cumulative incidence of estimated dropout was 8.9% at 6 months; size of the maximum nodule (≥3 cm) and nonachievement of complete response were independent factors. Extrahepatic progression developed in 16 patients (2.7%) within 1 year; size of the maximum nodule (4 cm) and alpha-fetoprotein level (>100 ng/mL) were independent predictors.

CONCLUSIONS

The estimated dropout rate from the waiting list within 6 months was 8.9%. Advantage points might be needed for patients with maximum nodule size ≥3 cm or those with noncomplete response. However, in patients with maximum nodule size ≥4 cm or alpha-fetoprotein level >100 ng/mL, caution is needed.

Additional lesions seen in magnetic resonance imaging of breast cancer patients: the role of second-look ultrasound and imaging-guided interventions

PURPOSE

The purpose of this study was to investigate the final outcomes of magnetic resonance imaging (MRI)-identified additional lesions (MRALs) in breast cancer patients and the role of second-look ultrasound (SLUS) and imaging-guided interventions.

METHODS

We analyzed breast cancer patients with MRALs on preoperative MRI between January and June 2012. MRALs were defined as additional lesions suspected on MRI but not suspected on mammograms or ultrasound. The malignancy rate of MRALs, MRI-based Breast Imaging Reporting and Database System (BI-RADS) category, positional relationship with the index cancer, MRI-concordant lesion visibility on SLUS, performance of imaging-guided interventions, and total mastectomy (TM) rates were evaluated for the confirmed lesions.

RESULTS

Among the 119 confirmed lesions, SLUS and imaging-guided interventions were performed in 94 (79.0%) and 82 cases (68.9%), respectively. The malignancy rate was 68.1% (81 of 119), and was significantly higher in BI-RADS 4C-5 lesions than in 4A-4B lesions (94.6% vs. 56.1%, P<0.01) and in ipsilateral same-quadrant lesions than in contralateral lesions (84.2% vs. 33.3%, P<0.01). The lesion visibility rate on SLUS was 90.4%. The malignancy rate was not significantly different according to lesion visibility on SLUS. The TM rate in the 98 cases with ipsilateral MRALs was 37.8%, while it was significantly lower in patients who underwent an imaging-guided intervention than in those who did not (27.9% vs. 54.1%, P=0.017).

CONCLUSION

MRALs show a high probability of malignancy, especially if they are ipsilateral. SLUS and imaging-guided interventions can eliminate many unnecessary TMs.

Shallow whole genome sequencing for robust copy number profiling of formalin-fixed paraffin-embedded breast cancers

Pathology archives with linked clinical data are an invaluable resource for translational research, with the limitation that most cancer samples are formalin-fixed paraffin-embedded (FFPE) tissues. Therefore, FFPE tissues are an important resource for genomic profiling studies but are under-utilised due to the low amount and quality of extracted nucleic acids. We profiled the copy number landscape of 356 breast cancer patients using DNA extracted FFPE tissues by shallow whole genome sequencing. We generated a total of 491 sequencing libraries from 2 kits and obtained data from 98.4% of libraries with 86.4% being of good quality. We generated libraries from as low as 3.8 ng of input DNA and found that the success was independent of input DNA amount and quality, processing site and age of the fixed tissues. Since copy number alterations (CNA) play a major role in breast cancer, it is imperative that we are able to use FFPE archives and we have shown in this study that sWGS is a robust method to do such profiling.

Abstract P6-08-09: Incidence and risk factors for congestive heart failure in early breast cancer received anthracycline and/or trastuzumab; big-data analysis of Korean health insurance review and assessment service database

Background: Anthracycline (AC) and/or trastuzumab (T) are the most commonly used for neo-/adjuvant therapy for early breast cancer. However, use of those regimens are limited owing to congestive heart failure (CHF). Although reported incidence from pivotal trials is very low and acceptable, no big data-based population study has not been conducted in Koreans yet. The aim of this study was to analyze the incidence, time to occurrence, and risk factors for CHF in patients with early breast cancer, who were treated with AC and/or T therapy, in Korea.

Methods: We used the Health Insurance Review and Assessment Service database and included women with no prior history of CHF who were aged &gt;19 years and diagnosed as having early breast cancer between 2007 and 2016. Only patients who had received breast cancer surgery and AC and/or T therapy were included. Patients with metastatic cancer codes were excluded.

Result: In total, 86,086 patients were included for this analysis. The incidence and median time to occurrence of CHF according to chemotherapy type were, 3.27% and 683.5 days in the AC only group, 6.39% and 374 days in the AC followed by T group, and 4.43% and 286 days in the T with or without non-AC group, respectively.

The multivariate Cox regression analysis revealed that the adjusted hazard ratio (HR) for CHF was increased with older age; in those aged ≥65 years versus &lt;50 years (HR, 2.79; 95% confidence interval [CI], 2.50–3.12). The HR in the AC followed by T group was significantly higher than that in the AC only group (HR, 2.21; 95% CI, 2.05-2.37). The T with or without non-AC group also showed a significantly higher HR than the AC only group (HR, 1.67; 95% CI, 1.37-2.04). CCI scores of ≥2 were significant predictors of CHF; score 2 versus 0 (HR, 1.30; 95% CI, 1.18-1.45), and score ≥3 versus 0 (HR, 1.87; 95% CI, 1.69-2.06). In addition, preexisting medical conditions were significant predictors for CHF: hypertension (HR, 1.58; 95% CI, 1.45-1.72), diabetes (HR, 1.17; 95% CI, 1.07-1.28), and ischemic heart disease (HR, 1.60; 95% CI, 1.45-1.76).

Conclusion: This is the first big data-based population study in Korea on the development of CHF after treatment with AC and/or T. The overall incidence of CHF was 3% to 6%, with a median time to occurrence of 1 to 2 years. Adjusted HR increased with older age, AC followed by T therapy, CCI scores ≥2, and preexisting conditions.

Table 1. Incidence and median time to occurrence of congestive heart failure according to chemotherapy typeChemotherapy typeTotalCHF event (%)Median time to occurenceAC only66,6992,182 (3.27%)683.5AC followed by T17,0621,090 (6.39%)374T ± non-AC2,325103 (4.43%)286

Table 2. Cox proportional hazards model for congestive heart failure, adjusted for age, chemotherapy type, and Charlson comorbidity index scoreVariableP-valueHR95% CIAge (ref &lt;50 years)   50-64 years&lt;0.00011.541.43-1.66≥65 years&lt;0.00012.792.50-3.12Chemotherapy type (ref AC only)   AC folloewed by T&lt;0.00012.212.05-2.37T ± non-AC&lt;0.00011.671.37-2.04Charlson comorbidity index score (ref 0)   10.12061.080.98-1.192&lt;0.00011.301.18-1.45≥3&lt;0.00011.871.69-2.06

Citation Format: Choi JY, Cho EY, Lee JW, Kim JW, Choi YJ, You JY, Bae SY, Jung SP, Cho KR, Park KH. Incidence and risk factors for congestive heart failure in early breast cancer received anthracycline and/or trastuzumab; big-data analysis of Korean health insurance review and assessment service database [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-08-09.

NanoString nCounter® Approach in Breast Cancer: A Comparative Analysis with Quantitative Real-Time Polymerase Chain Reaction, In Situ Hybridization, and Immunohistochemistry

Purpose

Accurate testing for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) is essential for breast cancer treatment. At present, immunohistochemistry (IHC)/florescence in situ hybridization (FISH) are widely accepted as the standard testing methods. To investigate the value of NanoString nCounter®, we performed its comparative analysis with IHC/FISH and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) for the assessment of ER, PR, and HER2.

Methods

Data on IHC/FISH results for ER, PR, and HER2 in 240 patients from a single tertiary hospital in Korea were collected and compared with NanoString nCounter® and qRT-PCR results at a single institution.

Results

Expression levels for each gene using NanoString nCounter® showed good correlation with the corresponding data for protein expression by IHC (p<0.001) and gene amplification status for HER2 (p<0.001). Comparisons between gene expression and IHC data showed good overall agreement with a high area under the curve (AUC) for ESR1/ER (AUC=0.939), PgR/PR (AUC=0.796), and HER2/HER2 (AUC=0.989) (p<0.001).

Conclusion

The quantification of ER, PgR, and HER2 mRNA expression with NanoString nCounter® may be a viable alternative to conventional IHC/FISH methods.

Evaluation of Pathologic Complete Response in Breast Cancer Patients Treated with Neoadjuvant Chemotherapy: Experience in a Single Institution over a 10-Year Period

BACKGROUND

Pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) has been associated with favorable clinical outcome in breast cancer patients. However, the possibility that the prognostic significance of pCR differs among various definitions has not been established.

METHODS

We retrospectively evaluated the pathologic response after NAC in 353 breast cancer patients and compared the prognoses after applying the following different definitions of pCR: ypT0/is, ypT0, ypT0/is ypN0, and ypT0 ypN0.

RESULTS

pCR was significantly associated with improved distant disease-free survival (DDFS) regardless of the definition (ypT0/is, p = .002; ypT0, p = .008; ypT0/is ypN0, p < .001; ypT0 ypN0, p = .003). Presence of tumor deposits of any size in the lymph nodes (LNs; ypN ≥ 0(i+)) was associated with worse DDFS (ypT0 ypN0 vs ypT0 ypN ≥ 0(i+), p = .036 and ypT0/is ypN0 vs ypT0/is ypN ≥ 0(i+), p = .015), and presence of isolated tumor cells was associated with decreased overall survival (OS; ypT0/is ypN0 vs ypT0/is ypN0(i+), p = .013). Residual ductal carcinoma in situ regardless of LN status showed no significant difference in DDFS or OS (DDFS: ypT0 vs ypTis, p = .373 and ypT0 ypN0 vs ypTis ypN0, p = .462; OS: ypT0 vs ypTis, p = .441 and ypT0 ypN0 vs ypTis ypN0, p = .758). In subsequent analysis using ypT0/is ypN0, pCR was associated with improved DDFS and OS in triple-negative tumors (p < .001 and p = .003, respectively).

CONCLUSIONS

Based on our study results, the prognosis and rate of pCR differ according to the definition of pCR and ypT0/is ypN0 might be considered a more preferable definition of pCR.

Clinical outcomes according to molecular subtypes in stage II-III breast cancer patients treated with neoadjuvant chemotherapy followed by surgery and radiotherapy

AIM

We evaluated the tumor response and clinical outcomes according to molecular subtypes in stage II-III breast cancer patients who received neo-adjuvant chemotherapy (NAC) followed by surgery and radiotherapy.

METHODS

We retrospectively analyzed 329 patients with clinical stage II-III breast cancer who received NAC followed by surgery and radiotherapy. Luminal A and B, HER2-enriched and triple-negative subgroups were identified.

RESULTS

The overall pathologic complete response (pCR) rate after NAC was 20.1% and the HER2-enriched subgroup had the highest pCR rate (43.6%), whereas luminal A showed the lowest rate of pCR (4.6%). The median follow-up duration was 55 months (range, 5-98 months). The 5-year overall survival (OS) and disease-free survival (DFS) rates were 88.9% and 72.9%, respectively. In subgroup analysis, according to the pathologic response (pCR vs non-pCR), the triple-negative subtype exhibited a significant difference in 5-year OS rate (100.0% vs 71.6%, P = 0.005) and 5-year DFS rate (93.1% vs 55.1%, P < 0.001). A distinct survival difference according to molecular subtype was found, particularly in the non-pCR group (5-year OS and DFS, P < 0.001, respectively).

CONCLUSIONS

The non-pCR group showed significantly decreased 5-year OS and DFS rates compared to the pCR group, especially in triple negative and HER2-enriched breast cancer patients. A significant difference in survival rates and molecular subtypes was found in patients who failed to attain pCR.

Radiologic Findings of Primary Mucinous Cystadenocarcinoma of the Breast: A Report of Two Cases and a Literature Review

Primary mucinous cystadenocarcinoma (MCA) of the breast is a rare but pathologically distinct breast tumor. There have been some case reports on primary MCA of the breast; however, they have all focused on pathologic findings. Here, we report the radiologic findings of two cases of MCA along with a review of the literature. Breast MCA shows a circumscribed mass with some calcifications on mammography, an intracystic solid mass without increased vascularity or a vascular stalk on ultrasound, and a heterogeneously enhancing mass within a rim-enhancing cyst with intermediate signal intensity on T2-weighted magnetic resonance imaging. These radiologic findings and the presence of mucin in the percutaneous biopsy specimen should suggest the possibility of MCA in the differential diagnosis of a breast tumor.

Overexpression of β-Catenin and Cyclin D1 is Associated with Poor Overall Survival in Patients with Stage IA-IIA Squamous Cell Lung Cancer Irrespective of Adjuvant Chemotherapy

INTRODUCTION

This study was aimed at understanding the effect of β-catenin and cyclin D1 on overall survival in patients with early-stage NSCLC and at evaluating if the prognostic effect can be modified by adjuvant chemotherapy.

METHODS

We retrospectively analyzed the expression of β-catenin and cyclin D1 using immunohistochemistry in formalin-fixed paraffin-embedded tissues from 576 patients with early-stage NSCLC.

RESULTS

The median duration of follow-up was 5.1 years. Overexpression of β-catenin and cyclin D1 was found in 56% and 50% of 576 cases, respectively. Overexpression of β-catenin and cyclin D1 was significantly associated with poor overall survival (p = 0.003 and p = 0.0009, respectively; log rank test) in squamous cell carcinomas, not in adenocarcinomas. The prognostic significance of each protein in the squamous cell carcinomas was limited to stages IA, IB, and IIA. In addition, simultaneous overexpression of β-catenin and cyclin D1 in the squamous cell carcinomas synergistically increased hazard ratios (HRs) 15.79 (95% confidence interval [CI] = 1.09-51.23; p =0.04) for stage IA, 10.30 (95% CI = 2.29-46.41; p = 0.002) for stage 1B, and 3.55 (95% CI = 1.22-10.36; p = 0.02) times for stage 2A compared to those without overexpression of the two proteins, after adjusting for confounding factors. In addition, the effect was not dependent on adjuvant chemotherapy.

CONCLUSIONS

The present study suggests that simultaneous overexpression of β-catenin and cyclin D1 may be associated with poor overall survival irrespective of platinum-based adjuvant chemotherapy in stage IA-IIA squamous cell carcinoma of the lung.

Expression of FOXM1 and related proteins in breast cancer molecular subtypes

Forkhead box (FOX) proteins constitute an extended family of transcriptional regulators. FOXM1 is ubiquitously expressed in cells undergoing proliferation, and overexpression of FOXM1 is associated with poor prognosis in various malignant tumours. FOXM1 and FOXO3a are often transcriptionally antagonistic. FOXO3a plays a critical tumour-suppressive role in breast cancer. FOXO activity is modulated by its acetylation status, which is regulated by class III histone deacetylases (sirtuins; also known as SIRTs). This study evaluated the role of FOX proteins and their regulators in each molecular subtype of breast cancer. Immunohistochemical expressions of FOXM1, FOXO3a, SIRT1 and SIRT6 were evaluated in tissue microarray blocks containing 688 consecutive breast cancer samples. Mean expression levels were used to categorize tumours according to the expression of each protein (high or low). High expression of FOXM1 was significantly correlated with high SIRT1 and SIRT6 expression, higher histologic grade and triple-negative breast cancer (TNBC). High expression of nuclear FOXO3a and nuclear SIRT1 was correlated with a lower histologic grade and the hormone receptor-positive/HER2-negative subtype. In survival analysis, FOXM1 was an independent adverse prognostic factor for disease-free and overall survival in the hormone receptor-positive/HER2-negative subtype but not in the HER2-positive subtype or TNBC. In conclusion, although high FOXM1 expression was noted in the TNBC subtype, it had no prognostic impact in TNBC. However, it had prognostic significance in the hormone receptor-positive/HER2-negative subtype.

Shear-wave elastography in invasive ductal carcinoma: correlation between quantitative maximum elasticity value and detailed pathological findings

BACKGROUND

Further information is needed regarding whether histopathological characteristics affect breast tumor elasticity.

PURPOSE

To determine whether maximum elasticity values vary according to tumor-stroma ratio, dominant stroma type, or presence of fibrosis in invasive breast cancer.

MATERIAL AND METHODS

This study included 71 patients with invasive ductal carcinoma not otherwise specified (IDC NOS) who underwent breast shear-wave elastography (SWE). Maximum elasticity (Emax) values were retrospectively correlated with pathological findings that included tumor-stroma ratio, dominant stroma type (collagen, fibroblast, lymphocyte), and fibrosis. Multiple linear regression analysis was performed to determine variables independently associated with Emax.

RESULTS

High histologic grade was significantly correlated with higher Emax (P = 0.042). Estrogen receptor and progesterone receptor expression negatively correlated with high elasticity values (P = 0.013 and P = 0.03, respectively). Breast cancers that exhibited higher cellularity demonstrated a greater level of stiffness that was not statistically significant (ρ = 0.153; P = 0.193). While dominant stroma type and fibrosis did not affect Emax (P = 0.197 and P = 0.598, respectively), lesion size was significantly associated with Emax (ρ = 0.474, P < 0.001). On multivariate analysis, only lesion size was significantly associated with Emax (P < 0.001).

CONCLUSION

The composition of tumors did not affect their Emax.

Comparative analysis of BRCA1 and BRCA2 variants of uncertain significance in patients with breast cancer: a multifactorial probability-based model versus ACMG standards and guidelines for interpreting sequence variants

PURPOSE

To investigate variants of uncertain significance (VUS) in BRCA1 and BRCA2, we assessed the multifactorial posterior probability of VUS in BRCA1 and BRCA2 and compared these analyses with interpretations according to the recently released American College of Medical Genetics and Genomics (ACMG) standards and guidelines.

METHODS

The analysis involved 715 Korean patients with breast cancer. The multifactorial probability of a VUS was analyzed using the prior probability and combined likelihoods of personal and family history, the pathologic profile of the breast cancer, and co-occurrence with pathogenic variants. Results were compared with those obtained according to the ACMG standards/guidelines.

RESULTS

Sixteen VUS from 51 BRCA1 VUS carriers and 28 VUS from 62 BRCA2 VUS carriers were analyzed. There was a slight agreement between the two analyses, with a kappa value of 0.14 (95% confidence interval (CI) = -0.34 to 0.62) for the BRCA1 VUS and a kappa value of 0.17 (95% CI = -0.10 to 0.49) for the BRCA2 VUS.

CONCLUSION

We propose that genetic counseling should be based on the concordant results between these two analyses. When discrepancies are found, those variants are still considered VUS and careful counseling should be provided.Genet Med 18 12, 1250-1257.

Association between Mutation and Expression of TP53 as a Potential Prognostic Marker of Triple-Negative Breast Cancer

Purpose

TP53, the most frequently mutated gene in breast cancer, is more frequently altered in HER2-enriched and basal-like breast cancer. However, no studies have clarified the role of TP53 status as a prognostic and predictive marker of triple-negative breast cancer (TNBC).

Materials and Methods

We performed p53 immunohistochemistry (IHC), nCounter mRNA expression assay, and DNA sequencing to determine the relationship between TP53 alteration and clinical outcomes of TNBC patients.

Results

Seventy-seven of 174 TNBC patients were found to harbor a TP53 mutation. Patients with missense mutations showed high protein expression in contrast to patients with deletion mutations (positivity of IHC: wild type vs. missense vs. deletion mutation, 53.6% vs. 89.8% vs. 25.0%, respectively; p < 0.001). TP53 mRNA expression was influenced by mutation status (mRNA expression [median]: wild type vs. missense vs. deletion mutation, 207.36± 132.73 vs. 339.61±143.21 vs. 99.53±99.57, respectively; p < 0.001). According to survival analysis, neither class of mutation nor protein or mRNA expression status had any impact on patient prognosis. In subgroup analysis, low mRNA expression was associated with poor prognosis in patients with a TP53 missense mutation (5-year distant recurrence-free survival [5Y DRFS]: low vs. high, 50.0% vs. 87.8%; p=0.009), while high mRNA expression with a TP53 deletion mutation indicated poor prognosis (5Y DRFS: low vs. high, 91.7% vs. 75.0%; p=0.316).

Conclusion

Association between TP53 mutation and expression indicates a potential prognostic marker of TNBC; hence both DNA sequencing and mRNA expression analysis may be required to predict the prognosis of TNBC patients.

Assessment of Invasive Breast Cancer Heterogeneity Using Whole-Tumor Magnetic Resonance Imaging Texture Analysis: Correlations With Detailed Pathological Findings

There is no study that investigates the potential correlation between the heterogeneity obtained from texture analysis of medical images and the heterogeneity observed from histopathological findings. We investigated whether texture analysis of magnetic resonance images correlates with histopathological findings.Seventy-five patients with estrogen receptor positive invasive ductal carcinoma who underwent preoperative breast magnetic resonance imaging (MRI) were included. Tumor entropy and uniformity were determined on T2- and contrast-enhanced T1-weighted subtraction images under different filter levels. Two pathologists evaluated the detailed histopathological findings of the tumors including tumor cellularity, dominant stroma type, central scar, histologic grade, extensive intraductal component (EIC), and lymphovascular invasion. Entropy and uniformity values on both T2- and contrast-enhanced T1-weighted subtraction images were compared with detailed pathological findings.In a multivariate analysis, entropy significantly increased only on unfiltered T2-weighted images (P = 0.013). Tumor cellularity and predominant stroma did not affect the uniformity or entropy on both T2- and contrast-enhanced T1-weighted subtraction images. High histologic grades showed increased uniformity and decreased entropy on contrast-enhanced T1-weighted subtraction images, whereas the opposite tendency was observed on T2-weighted images. Invasive ductal carcinoma with an EIC or lymphovascular invasion only affected the contrast-enhanced T1-weighted subtraction images, through increased uniformity and decreased entropy. The best uniformity results were recorded on T2- and contrast-enhanced T1-weighted subtraction images at a filter level of 0.5. Entropy showed the best results at a filter level of 0.5 on contrast-enhanced T1-weighted subtraction images. However, on T2-weighted images, an ideal model was achieved on unfiltered images.MRI texture analysis correlated with pathological tumor heterogeneity.

Expression of Cyclooxygenase-2 and Tumor Microvessel Density in Colorectal Cancer

PURPOSE

The increased expression of cyclooxygenase (COX)-2 has been implicated in the development and progression of human cancer. This study investigated the COX-2 expression in colorectal cancer, and its relationships with tumor angiogenesis and the clinicopathological factors.

MATERIALS AND METHODS

The expression of the COX-2 protein and microvessel density were evaluated, using immunohistochemical methods, in 21 normal colonic mucosa and 190 human colorectal carcinomas. Correlations between COX-2 expression and microvessel density, as well as various clinicopathological factors, were studied in colorectal carcinomas.

RESULTS

The COX-2 protein expression in epithelial cells was increased in 169 of the 190 adenocarcinoma cases (88.9%), but in only 1 of the 21 (4.8%) normal mucosa cases. The COX-2 expression was significantly increased in the differentiated compared with the undifferentiated colorectal carcinomas (p<0.05), and significantly correlated with the depth of invasion and microvessel density (p<0.05). Rectal cancers had more COX-2 positive cases than the colon cancers (p<0.05). However, there were no significant differences in the tumor size and the presence of lymphatic or vascular invasion.

CONCLUSION

The overexpression of cyclooxygenase-2 in colorectal carcinomas seems to play a role in the invasion and angiogenesis of the tumors, so may be a useful marker of the prognosis. The prominent expression was also demonstrated in differentiated colorectal cancers.

Initial Experience with a Wireless Ultrasound-Guided Vacuum-Assisted Breast Biopsy Device

Objective

To determine the imaging characteristic of frequent target lesions of wireless ultrasound (US)-guided, vacuum-assisted breast biopsy (Wi-UVAB) and to evaluate diagnostic yield, accuracy and complication of the device in indeterminate breast lesions.

Materials and Methods

From March 2013 to October 2014, 114 women (age range, 29–76 years; mean age, 50.0 years) underwent Wi-UVAB using a 13-gauge needle (Mammotome Elite^®; Devicor Medical Products, Cincinnati, OH, USA). In 103 lesions of 96 women with surgical (n = 81) or follow-up (n = 22) data, complications, biopsy procedure, imaging findings of biopsy targets and histologic results were reviewed.

Results

Mean number of biopsy cores was 10 (range 4–25). Nine patients developed moderate bleeding. All lesions were suspicious on US, and included non-mass lesions (67.0%) and mass lesions (33.0%). Visible calcifications on US were evident in 57.3% of the target lesions. Most of the lesions (93.2%) were nonpalpable. Sixty-six (64.1%) were malignant [ductal carcinoma in situ (DCIS) rate, 61%] and 12 were high-risk lesions (11.7%). Histologic underestimation was identified in 11 of 40 (27.5%). DCIS cases and in 3 of 9 (33.3%) high-risk lesions necessitating surgery. There was no false-negative case.

Conclusion

Wi-UVAB is very handy and advantageous for US-unapparent non-mass lesions to diagnose DCIS, especially for calcification cases. Histologic underestimation is unavoidable; still, Wi-UVAB is safe and accurate to diagnose a malignancy.

Nano Josephson superconducting tunnel junctions in YBa2Cu3O(7-δ) directly patterned with a focused helium ion beam

Since the discovery of the high-transition-temperature superconductors (HTSs), researchers have explored many methods to fabricate superconducting tunnel junctions from these materials for basic science purposes and applications. HTS circuits operating at liquid-nitrogen temperatures (∼77 K) would significantly reduce power requirements in comparison with those fabricated from conventional superconductors. The difficulty is that the superconducting coherence length is very short and anisotropic in these materials, typically ∼2 nm in the a-b plane and ∼0.2 nm along the c axis. The electrical properties of Josephson junctions are therefore sensitive to chemical variations and structural defects on atomic length scales. To make multiple uniform HTS junctions, control at the atomic level is required. In this Letter we demonstrate all-HTS Josephson superconducting tunnel junctions created by using a 500-pm-diameter focused beam of helium ions to directly write tunnel barriers into YBa2Cu3O(7-δ) (YBCO) thin films. We demonstrate the ability to control the barrier properties continuously from conducting to insulating by varying the irradiation dose. This technique could provide a reliable and reproducible pathway for scaling up quantum-mechanical circuits operating at liquid-nitrogen temperatures, as well as an avenue to conduct novel planar superconducting tunnelling studies for basic science.

Prognostic Modeling in Pathologic N1 Breast Cancer Without Elective Nodal Irradiation After Current Standard Systemic Management

OBJECTIVE

This study was conducted to establish a prognostic model in patients with pathologic N1 (pN1) breast cancer who have not undergone elective nodal irradiation (ENI) under the current standard management and to suggest possible indications for ENI.

METHODS

We performed a retrospective study with patients with pN1 breast cancer who received the standard local and preferred adjuvant chemotherapy treatment without neoadjuvant chemotherapy and ENI from January 2005 to June 2011. Most of the indicated patients received endocrine and trastuzumab therapy.

RESULTS

In 735 enrolled patients, the median follow-up period was 58.4 months (range, 7.2-111.3 months). Overall, 55 recurrences (7.4%) developed, and locoregional recurrence was present in 27 patients (3.8%). Recurrence-free survival was significantly related to lymphovascular invasion (P = .04, hazard ratio [HR], 1.83; 95% confidence interval [CI], 1.03-2.88), histologic grade (P = .03, HR, 2.57; 95% CI, 1.05-6.26), and nonluminal A subtype (P = .02, HR, 3.04; 95% CI, 1.23-7.49) in multivariate analysis. The prognostic model was established by these 3 prognostic factors. Recurrence-free survival was less than 90% at 5 years in cases with 2 or 3 factors.

CONCLUSIONS

The prognostic model has stratified risk groups in pN1 breast cancer without ENI. Patients with 2 or more factors should be considered for ENI.

Abstract P3-06-20: A seven-gene signature can predict distant recurrence in patients with triple-negative breast cancers (TNBCs) who receive adjuvant chemotherapy following curative surgery of the primary breast cancer

BACKGROUND: Women with triple-negative breast cancers (TNBCs) represent a significant treatment challenge as they have a relatively poor prognosis and no effective targeted therapy exists. Although TNBCs are often discussed as a single disease entity of breast cancers, in fact they are very heterogeneous. The aim of this study was to investigate candidate genes that might function as biomarkers to differentiate TNBCs among patients, who received adjuvant chemotherapy after curative surgery, into those with high or low risk for distant recurrence.

METHODS: We tested whether the results of a NanoString expression assay that targeted 245 prospectively selected genes and used mRNA extracted from paraffin wax-embedded tumor tissues would predict distant recurrence in patients with TNBC. The levels of expression of seven genes were used in a prospectively defined algorithm to allocate each patient to a risk group (low or high).

RESULTS: NanoString expression profiles were obtained for 203 tumor tissue blocks. Increased expressions of the five genes (SMAD2, HRAS, KRT6A, TP63, and ETV6) and decreased expression of the two genes (NFKB1 and MDM4) were associated favorable prognosis in this patients’ cohort and were validated with cross-validation. The proportions of patients categorized as having low or high risk were 75% and 25%, respectively. The Kaplan–Meier estimates of the rates of distant recurrence at 10 years in the low- and high-risk groups according to gene expression signature were 62% (95% CI, 48.6–78.9%) and 85% (95% confidence interval, CI, 79.2–90.7%), respectively. When adjusting for tumor–node–metastasis (TNM) stage, the distant recurrence-free survival (DRFS)s in the low-risk groups were significantly longer than that in the high-risk group (p&lt;.001) in each of TNM stages I plus II, and III. In a multivariate Cox regression model, the gene expression signature provided significant predictive power jointly with the TNM staging system.

CONCLUSION: A seven-gene signature could be used as a prognostic model to predict DRFS in patients with TNBC who received curative surgery followed by adjuvant chemotherapy.

Citation Format: Yeon Hee Park, Hae Hyun Jung, In-Gu Do, Eun Yoon Cho, Insuk Sohn, Sin-Ho Jung, Won Ho Kil, Seok Won Kim, Jeong Eon Lee, Seok Jin Nam, Jin Seok Ahn, Young-Hyuck Im. A seven-gene signature can predict distant recurrence in patients with triple-negative breast cancers (TNBCs) who receive adjuvant chemotherapy following curative surgery of the primary breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P3-06-20.