INSM1 is a novel prognostic neuroendocrine marker for luminal B breast cancer.

Insulinoma associated protein 1 (INSM1) is a relatively new marker of neuroendocrine differentiation. It has been shown to have a high sensitivity for neuroendocrine tumours arising from different organs. This study evaluated INSM1 as a marker for neuroendocrine differentiation in infiltrating breast cancers (IBC). The expression of INSM1, together with other neuroendocrine markers (synaptophysin, chromogranin and CD56) was assessed in a large IBC cohort using tissue microarray by immunohistochemistry. Overall, 13.1%, 4.6%, 7.0% and 6.5% of the cases were positive for synaptophysin, chromogranin, INSM1 and CD56, respectively. INSM1 expression showed similar clinicopathological and biomarker profiles as chromogranin and synaptophysin. They were associated positively with luminal profile (p<0.001) and hormone receptors expression (p≤0.015), but negatively with HER2 (p≤0.044) and high molecular weight cytokeratins (p≤0.047). Using synaptophysin and/or chromogranin to define neuroendocrine differentiation, INSM1 showed a sensitivity of 37.3%, and was more sensitive than chromogranin (33.5%) and CD56 (16.4%) but less than synaptophysin (94.6%). Interestingly, INSM1 expression segregated IBC with neuroendocrine differentiation into different prognostic subgroups, particularly within luminal B subtype. Among the synaptophysin/chromogranin+ luminal B cancers, INSM1 expression was associated with significantly better survival (DFS: χ2=8.009, p=0.004; BCSS: χ2=3.873, p=0.049). Multivariate analysis showed that synaptophysin/chromogranin+ INSM1- status was an independent adverse factor for DFS (HR=2.282, 95%CI=1.196-4.356, p=0.012) in the luminal B subtype. Our data supported the usefulness of INSM1 in detecting neuroendocrine differentiation in IBC. Furthermore, INSM1 expression suggested a favourable prognostic impact; thus, it could be useful for stratifying neuroendocrine tumours with different prognosis.

Combined SOX10 GATA3 is most sensitive in detecting primary and metastatic breast cancers: a comparative study of breast markers in multiple tumors.

PURPOSE: For invasive breast cancer (IBC), high SOX10 expression was reported particularly in TNBC. This raised the possibility that SOX10 may complement other breast markers for determining cancers of breast origin. METHODS: Here, we compared the expression of SOX10 with other breast markers (GATA3, mammaglobin and GCDFP15) and their combined expression in a large cohort of IBC together with nodal metastases. We have also evaluated the expression of GATA3 and SOX10 in a wide spectrum of non-breast carcinomas to assess their value as breast specific markers. RESULTS: Compared with other markers, SOX10 showed lower overall sensitivity (6.5%), but higher sensitivity in TNBC (31.4%) than other breast markers including GATA3 (29.7% for TNBC). Its expression demonstrated the highest concordance between the paired IBC and nodal metastases (96.4%, κ = 0.663) among all the breast markers. More importantly, SOX10 identified many GATA3-negative TNBC, thus the SOX10/GATA3 combination was the most sensitive marker combination for IBC (86.6%). For non-breast carcinoma, a high SOX10/GATA3 expression rate was found in melanoma (77.9%, predominately expressed SOX10), urothelial carcinoma (82.0%, predominately expressed GATA3) and salivary gland tumors (69.4%). Other carcinomas, including cancers from lungs, showed very low expression for the marker combination. CONCLUSIONS: The data suggested that SOX10/GATA3 combination can be used for differentiating metastases of breast and multiple non-breast origins. However, the differentiation with melanoma and urothelial tumors required more careful histologic examination, thorough clinical information and additional site-specific IHC markers. For salivary gland tumors, the overlapping tumor types with IBC renders the differentiation difficult.

The significance of highlighting the oestrogen receptor low category in breast cancer.

The latest ASCO/CAP guideline has recommended to report oestrogen receptor (ER) low cases (ERlo; 1-10%) as "ER low positive category", prompting us to compare the clinicopathologic features, biomarkers, survival and treatment of the ERlo cases with other subgroups (ER negative (ERneg) and ER high (ERhi)). ERlo cases revealed more similar clinicopathologic and biomarker profiles (including younger age, larger tumour, high proliferation, HER2 and basal markers expression) to ERneg than ERhi cancers. The ERlo cases receiving hormonal therapy showed a similarly poor outcome as ERneg cancers. However, majority of ERlo cases were downstaged to stage I in the 8th AJCC pathological prognostic staging, highlighting a risk of potential under treatment. Overall, our data highlighted the differences of ERlo from other ERpos cases and their management should be considered separately.

The Clinical Significance of Neuroendocrine Features in Invasive Breast Carcinomas.

The latest World Health Organization (WHO) classification categorized invasive breast carcinomas (IBCs) with neuroendocrine (NE) differentiations into neuroendocrine neoplasms (including well-differentiated neuroendocrine tumor [NET] and poorly differentiated neuroendocrine carcinoma [NEC]) and IBC no special type with NE features (IBC-NST-NE). However, little is documented of the clinical significance of this classification; also the precise thresholds and choices of NE markers were variable. In the current study, a large cohort of patients with IBC with NE differentiation were morphologically classified based on the WHO criteria and the clinical relevance of expression of different NE markers (synaptophysin [SYN], chromogranin [CG], and CD56) was evaluated. Among 1,372 IBCs, 52 NET (3.8%) and 172 IBC-NST-NE (12.5%) were identified. Compared with the IBC-no NE cases, NET and IBC-NST-NE were similarly associated with positive estrogen receptor (ER) expression and lower grade (p < .001). For patient outcome, IBC-NST-NE, but not NET, demonstrated significantly worse survival than the IBC-no NE cases. Based on high (≥50%) and low (<50%) expression for each NE marker, independent poor disease-free survival for SYNlo CGlo and SYNhi CGlo cancers (IBC-no NE cases as references, hazard ratio [HR], ≤1.429; p ≤ .026) was found. Interestingly, SYN and CG expression correlated with each other and they shared similar clinicopathologic characteristics; but not with with CD56. In addition, CD56-only positive cases were associated with hormone receptors negativity and basal markers positivity (p ≤ .019), and patients' outcome was similar to IBC-no NE cancers. Our findings suggested that NE markers expression may provide information to fine tune treatment strategy. The relevance of CD56 as NE marker requires further studies. IMPLICATIONS FOR PRACTICE: Invasive breast carcinomas (IBCs) with neuroendocrine (NE) differentiation are heterogeneous in clinicopathologic parameters, biomarker expression, and prognosis. However, there are no specific therapies targeting NE differentiation, and all carcinomas with any NE differentiation are treated similarly as other IBCs. The results of this study suggest that stratification based on NE marker expression levels may provide added prognostically pertinent information, aiding better treatment strategy. In addition, CD56-only positive carcinomas showed a different clinicopathologic and biomarker expression profile compared with those with chromogranin and synaptophysin expression. Relevance of CD56 as an NE marker requires further studies.

Sry-related high-mobility-group/HMG box 10 (SOX10) as a sensitive marker for triple-negative breast cancer.

AIMS: Confirmation of a breast origin for triple-negative breast cancer (TNBC) is sometimes problematic. The traditional breast markers GATA-binding protein 3 (GATA3), mammaglobin (MGB) and gross cystic disease fluid protein 15 (GCDFP15) have shown limitations in identifying TNBC. Here, we aimed to examine the diagnostic potential of the newly proposed TNBC marker, Sry-related high-mobility-group/HMG box 10 (SOX10). METHODS AND RESULTS: We analysed and compared SOX10 expression with GATA3, MGB and GCDFP15 expression in a test cohort of 1838 invasive breast cancers (IBCs) by using tissue microarrays. The findings from the test cohort were further examined with a validation cohort of 42 TNBCs in whole sections. The overall expression rates of SOX10, GATA3, MGB and GCDFP15 were 6.9%, 83.1%, 47.0%, and 34.8%, respectively. Among the TNBCs within this cohort, the expression rates of SOX10, GATA3, MGB and GCDFP15 were 31.3%, 34.5%, 27.9%, and 25.2%, respectively. SOX10 was strongly associated with TNBC (P < 0.001), whereas all other traditional markers were associated with non-TNBC (P < 0.001 for all). In addition, SOX10 was more correlated to basal-like breast cancer (BLBC) (P = 0.001) than five-marker-negative subtype among the TNBCs. A high expression rate of SOX10 (81%) was confirmed in the validation cohort. Additionally, SOX10 expression was inversely correlated with GATA3 and GCDFP15 expression, so they may complement each other in TNBC detection. The SOX10-GATA3 combination yielded a sensitivity of 60.3% for TNBC detection in the test cohort. CONCLUSION: SOX10 is a reliable marker for identifying TNBC, and complements GATA3. The SOX10-GATA3 combination may be used as a sensitive TNBC marker.

Improved Prognostication for the Updated AJCC Breast Cancer Pathological Prognostic Staging Varied in Higher-Stage Groups.

BACKGROUND: In addition to TNM-based anatomical staging (AS), a novel pathological prognostic staging (PPS) has been proposed by the American Joint Committee on Cancer (AJCC). PPS demonstrated better prognostication, but its superiority in breast cancer subtypes and related to staging discrepancies between AS and PPS are not clear. METHODS: A cohort of 1729 patients with breast cancer was staged into AS and PPS according to the latest AJCC staging. Patient characteristic and restaging outcomes were compared. RESULTS: Compared with AS, 799 and 135 cases were upstaged and downstaged respectively in PPS, mostly involved stage I cases. For the overall cohort, PPS demonstrated superior prognostic power over AS in both disease-free survival (DFS) and breast cancer-specific survival. However, such superiority was found mainly in estrogen receptor (ER)/progesterone receptor (PR)+ but not ER-PR- cancers. Comparing the restaged cases within the same PPS, PPS 1A cases showed similar survival irrespective of the original AS. Interestingly, in other PPS groups (PPS 1B and higher), there was a difference in outcome among patients with same PPS but different AS. Within PPS 1B patients, downstaged cases from higher AS showed worse DFS (3A>1B vs. 2A>1B: χ2 = 4.732, P = .030). CONCLUSIONS: PPS may provide a more accurate prognostication, mostly among ER/PR+ cancers and with PPS 1A patients. Patients restaged to higher PPS stages showed significant differential survival even within the same PPS. Also, only limited improvement was observed for ER-PR- cancers. Caution needs to be exercised in using PPS for patient prognostication, as in some cases the outcome can be variable with the same PPS.

Co-expression of HLA-I loci improved prognostication in HER2+ breast cancers.

The underlying basis for cancer immune evasion is important for effective immunotherapy and prognosis in breast cancers. Human leucocyte antigens (HLA)-I comprising three classical antigens (HLA-A, -B and -C) is mandatory for anti-tumor immunity. Its loss occurred frequently in many cancers resulting in effective immune evasion. Most studies examined HLA-I as a whole. Alterations in specific locus could have different clinical ramifications. Hence, we evaluated the expression of the three HLA-I loci in a large cohort of breast cancers. Low expression of HLA-A, -B and -C were found in 71.1%, 66.3%, and 60.2% of the cases. Low and high expression in all loci was found in 48.3% and 17.9% of the cases respectively. The remaining showed high expression in one or two loci. Cases with all HLA high expression (all HLA high) was frequent in the ER-HER2- (27.4%) and ER-HER2+ (23.1%) cases and was associated with characteristic pathologic features related to these tumor (higher grade, necrosis, high tumor infiltrating lymphocyte (TIL), pT stage, low hormonal receptor, high basal marker expression) (p ≤ 0.019). Interestingly, in HER2+ cancers, only cases with all HLA high and high TIL showed significantly better survival. In node positive cancers, concordant high HLA expression in primary tumors and nodal metastases was favorable prognostically (DFS: HR = 0.741, p < 0.001; BCSS: HR = 0.699, p = 0.003). The data suggested an important clinical value of a combined analysis on the co-expression HLA-I status in both primary and metastatic tumors. This could be a potential additional key component to be incorporated into TIL evaluation for improved prognostication.

Founder Mutation c.1516A>C in KLHL40 Is a Frequent Cause of Nemaline Myopathy With Hyponatremia in Ethnic Chinese.

KLHL40-related nemaline myopathy is a severe autosomal recessive muscle disorder. The current study describes 4 cases of KLHL40-related nemaline myopathy in Hong Kong ethnic Chinese presenting within 3 years, which are confirmed with clinicopathologic features and genetic studies. The incidence is estimated to be at least 1 in 45 226 livebirths (at least 1 in 41 608 among ethnic Chinese livebirths) in Hong Kong. Hyponatremia appears to be another common feature in these patients. Salient histological features include nemaline bodies ranging from 200 to 500 nm in diameters on ultrastructural examination as well as negative KLHL40 immunohistochemistry; type II fiber predominance is obvious in 2 cases. We demonstrate the founder effect associated with genetic variant c.1516A>C (p.Thr506Pro) by polymorphic marker analysis, which revealed a 0.56-0.75-Mb or 0.41-0.78-cM shared haplotype encompassing the disease allele. The mutation is believed to have occurred around 412 generations ago or 6220 BCE, as estimated using DMLE+ and a formula described by Boehnke. We believe the founder variant might possibly underlie a sizable portion of nemaline myopathy in ethnic Chinese. Analysis of the KLHL40 gene may be considered as the first-tier testing of congenital myopathy in this ethnic group.

Predicting Outcome in Mammary Phyllodes Tumors: Relevance of Clinicopathological Features.

BACKGROUND: Phyllodes tumors (PTs) of the breast are uncommon fibroepithelial neoplasms. Most behave in a benign fashion but they also have the potential to recur locally or to metastasize. METHODS: In the current study involving 290 PTs (181 benign, 76 borderline, and 33 malignant) from three hospitals over an 11-year period, we assessed the relationship between histologic parameters (including histologic features affecting grade and surgical margin status), postoperative adjuvant treatment, and local recurrences and distant metastases. RESULTS: An involved surgical margin was the only factor associated with increased risk of local recurrences (hazard ratio [HR] 4.673, p = 0.003), but not for distant metastases. For local recurrences, a wider margin did not confer additional benefits. None of the histologic factors were predictive for local recurrences. In contrast, distant metastases were correlated with histologic parameters, particularly an infiltrative border (HR 10.935, p = 0.012) and the presence of necrosis (HR 15.311, p = 0.007). In this series, all local recurrences were found in patients without radiotherapy, regardless of surgical margin status. CONCLUSION: A negative surgical margin is mandatory for the effective local control of PT recurrence, and a minimal margin clearance may be sufficient. For distant metastases, the inherent characteristics of PTs are important, thus it may be prudent to evaluate additional histologic features, including necrosis, for patients' prognostication.

Diagnostic upgrade of atypical ductal hyperplasia of the breast based on evaluation of histopathological features and calcification on core needle biopsy.

AIMS: Atypical ductal hyperplasia (ADH) of breast is increasingly diagnosed in core needle biopsy (CNB). As higher-grade lesions were found in the excision in a substantial proportion of ADH on CNB, factors predicting risk of subsequent upgrade are clinically significant. This study aims to investigate relevant histopathological factors in CNB that could predict diagnostic upgrade at excision. METHODS AND RESULTS: One hundred and forty-three cases of CNB with paired subsequent excision were evaluated for multiple clinicopathological parameters related to CNB sampling, ADH morphology, calcification and other co-existing histological features, and which of these parameters were associated with diagnostic upgrade at subsequent excisions were determined. Forty-eight cases (34.3%) were upgraded to malignancy, including 15 invasive cancers and 33 ductal carcinomas in situ (DCIS). An increased tissue area occupied by ADH (P = 0.026), a higher number of ADH foci (P = 0.004), the presence of solid pattern (P = 0.037) and older age (P = 0.012) were positively associated with upgrade, while negative associations were found with the presence of micropapillary pattern (P = 0.025), co-existing columnar cell lesions (CCL) (P = 0.001) and the presence of calcifications (P = 0.009). Multivariate logistic regression analysis showed that the number of ADH foci (HR = 2.810, P = 0.013) was an independent positive predictor, while co-existing CCL (HR = 0.391, P = 0.013) was an independent negative predictor for upgrade. CONCLUSIONS: Patients with ADH in CNB showing the presence of co-existing CCL and a lower number of ADH foci have a lower risk of disease upgrade at excision, and are potential candidates for observation-only management.

The Clinical Value of PELP1 for Breast Cancer: A Comparison with Multiple Cancers and Analysis in Breast Cancer Subtypes.

PURPOSE: Proline, glutamic acid, and leucine-rich protein 1 (PELP1), a novel nuclear receptor (NR) co-regulator, is highly expressed in breast cancer. We investigated its expression in breast cancer subtypes, in comparison with other breast markers as well as cancers from different sites. Its prognostic relevance with different subtypes and other NR expression was also examined in breast cancers. METHODS: Immunohistochemical analysis was performed on totally 1,944 cancers from six different organs. RESULTS: PELP1 expression rate was the highest in breast cancers (70.5%) among different cancers. Compared to GATA3, mammaglobin and gross cystic disease fluid protein 15, PELP1 was less sensitive than GATA3 for luminal cancers, but was the most sensitive for non-luminal cancers. PELP1 has low expression rate (<20%) in colorectal cancers, gastric cancers and renal cell carcinomas, but higher in lung cancers (49.1%) and ovarian cancers (42.3%). In breast cancer, PELP1 expression was an independent adverse prognostic factor for non-luminal cancers (disease-free survival [DFS]: hazard ratio [HR], 1.403; p=0.012 and breast cancer specific survival [BCSS]: HR, 1.443; p=0.015). Interestingly, its expression affected the prognostication of androgen receptor (AR). ARposPELP1lo luminal cancer showed the best DFS (log-rank=8.563, p=0.036) while ARnegPELP1hi non-luminal cancers showed the worst DFS (log-rank=9.536, p=0.023). CONCLUSION: PELP1 is a sensitive marker for breast cancer, particularly non-luminal cases. However, its considerable expression in lung and ovarian cancers may limit its utility in differential diagnosis in some scenarios. PELP1 expression was associated with poor outcome in non-luminal cancers and modified the prognostic effects of AR, suggesting the potential significance of NR co-regulator in prognostication.

Expression of biomarkers in the AKT pathway correlates with malignancy and recurrence in phyllodes tumours of the breast.

AIMS: Phyllodes tumours (PTs) of the breast are uncommon fibroepithelial neoplasms with the potential to recur and metastasise. Apart from histological grading, the expression of biological markers and its relationship with tumour behaviour have been topics of interest. The phosphatidylinositol 3-kinase (PI3K)-AKT pathway regulates diverse biological functions, and is one of the most frequently deregulated pathways in cancers. Little is known of PI3K-AKT pathway alteration in PT. We aim to investigate the alterations in different component of AKT pathway in PTs. METHODS AND RESULTS: This study investigated the expression of four biological markers involved in this pathway (PTEN, INPP4B, PI3KCA and pAKT) in 134 PTs by the use of immunohistochemistry. According to an immunoscore incorporating staining intensity and proportion, low epithelial INPP4B expression (P = 0.045) was associated with recurrence. A trend of association was found for low epithelial PTEN expression with recurrence (P = 0.090). Interestingly, low epithelial INPP4B expression was also associated recurred tumours (P = 0.043). Stromal PI3KCA expression (P = 0.016) and pAKT expression (P = 0.006) were found to be correlated with increased histological grade, but an opposite trend was seen for stromal INPP4B expression (P = 0.018). In addition, epithelial and stromal PTEN expression, PI3KCA expression and pAKT expression showed strong correlations with each other (P ≤ 0.001). CONCLUSIONS: These findings indicate that alterations in AKT pathway activation may correlate with malignant transformation and recurrence in PT. Low epithelial INPP4B/PTEN expression is associated with shorter recurrence-free survival. These observations suggest that the pathway may play a crucial role in the biological behaviour and progression of PT, and assessing the expression of this pathway may be of value in diagnosis, grading, prognostication, and management.

Proteolytic cleavage of amyloid precursor protein by ADAM10 mediates proliferation and migration in breast cancer.

BACKGROUND: Amyloid precursor protein (APP), best known for its association with Alzheimer disease, has recently been implicated in breast cancer progression. However, the precise mechanism involved remains unclear. Here, we investigated the role of APP proteolytic cleavage in breast cancer functions. METHODS: The presence of APP proteolytic cleavage products was examined in breast cancer cell lines. The functional roles of APP in breast cancer were studied in vitro and tumor xenograft model using siRNA. The effects of full length APP and the α-secretase cleaved ectodomain fragment, soluble APPα (sAPPα) were further investigated for their overexpression in breast cancers. The α-secretase involved was identified. The α-secretase expression together with APP was examined in clinical breast cancers. RESULTS: We showed that APP underwent proteolytic cleavage in breast cancer cells to generate sAPPα. The sAPPα and full length protein mediated breast cancer migration and proliferation, but in different functional extent. This proteolytic cleavage was mediated by ADAM10. Downregulation of APP and ADAM10 brought about similar functional effects. Overexpression of sAPPα reversed the effects of ADAM10 downregulation. Interestingly, in patients with non-luminal breast cancers, APP and ADAM10 expression correlated with each other and their co-expression was associated with the worst outcome. CONCLUSIONS: These results demonstrated the contributory role of APP cleavage on its oncogenic roles in breast cancer. ADAM10 was the key α-secretase. APP and ADAM10 co-expression was associated with worse survival in non-luminal breast cancers. Targeting of APP or its processing by ADAM10 might be a promising treatment option in these cancers.

CD147 expression is associated with poor overall survival in chemotherapy treated triple-negative breast cancer.

AIMS: In breast cancer models, the functional roles of CD147 in proliferation, invasion and treatment resistance have been widely reported. However, there are only a few studies examining the clinicopathological correlation and prognostic relevance of CD147 in breast cancer, especially in relation to breast cancer molecular subtypes. METHODS: In this study, we analysed CD147 expression in a large cohort of breast cancers, correlating with clinicopathological features and the expression of a comprehensive panel of biomarkers in triple-negative breast cancer (TNBC) and non-TNBC subsets. Its relationship with patients' survival was also analysed. RESULTS: CD147 was expressed in 11.9%(140/1174) of all cases and in 23.8% (40/168) of TNBC. The expression was associated with tumour histological subtypes (p=0.01) and most commonly seen in carcinoma with medullary features (26.0%). CD147 expression correlated with high tumour grade, presence of necrosis and basal-like breast cancer (BLBC) subtype, high Ki67 and expression of some other basal markers and stem-like markers. CD147 expression was also associated with poor overall survival in chemotherapy treated patients with TNBC. CONCLUSIONS: CD147 is a putative marker in identifying TNBC or BLBC, and may be useful as a prognosis indicator for patients with TNBC or BLBC post chemotherapy.

Amyloid Precursor Protein Is Associated with Aggressive Behavior in Nonluminal Breast Cancers.

BACKGROUND: ß-amyloid precursor protein (APP), a potential target for Alzheimer's disease treatment, has recently been shown to take part in carcinogenesis. Increased APP promotes migration, survival, and proliferation in breast cancer cell lines. We examined the clinical value of APP in breast cancers. A comprehensive examination of clinicopathological features related to APP expression in a large cohort of breast cancers and the corresponding metastatic lymph nodes was performed. APP expression and its prognostic impact in different breast cancer subtypes were examined. RESULTS: APP was highly expressed in nonluminal breast cancers and correlated with features associated with nonluminal breast cancers (including higher grade, the presence of necrosis, and higher proliferative index, growth factor receptor, and basal marker expression). Multivariate Cox hazard analysis demonstrated that APP was an independent adverse prognostic factor of disease-free survival (DFS; hazard ratio [HR], 2.090; p = .013; 95% confidence interval [CI], 1.165-3.748) and breast cancer-specific survival (BCSS; HR, 2.631; p = .002; 95% CI, 1.408-4.915) in the nonluminal group. The independent prognostic impact was also seen in triple negative breast cancers. Interestingly, a higher expression of APP was found in nodal metastasis compared with primary tumor. Such APP upregulation was correlated with further distal metastasis and poorer outcome (DFS: log-rank, 12.848; p < .001; BCSS: log-rank, 13.947; p < .001). CONCLUSION: Our findings provided evidence of oncogenic roles of APP in clinical breast cancers. Patients with positive APP expression, particularly those with APP upregulation in lymph node metastases, may require vigilant monitoring of their disease and more aggressive therapy. IMPLICATIONS FOR PRACTICE: ß-amyloid precursor protein (APP), a potential target for Alzheimer's disease, has recently been implicated in oncogenesis. Here, evidence of its roles in clinical breast cancers is provided. Positive APP expression was found to be an independent prognostic factor in nonluminal cancers, particularly triple negative breast cancers (TNBCs). Interestingly, a higher APP in nodal metastases was associated with distal metastases. TNBCs are heterogeneous and currently have no available target therapy. APP could have therapeutic potential and be used to define the more aggressive cases in TNBCs. Current prognostic analysis is based on primary tumor. The present data suggest that investigation of nodal metastases could provide additional prognostic value.

GATA-3 is superior to GCDFP-15 and mammaglobin to identify primary and metastatic breast cancer.

PURPOSE: Despite numerous studies on the utility of GATA-3 as breast cancer marker, its comparison with other breast markers, its concordance between primary and metastatic tumors and its expression in primary cancers from sites with frequent breast metastases remains unclear. METHODS: To address these questions, totally 993 invasive breast cancers (IBC), 254 paired nodal metastases, 23 distant metastases, and 208 lung carcinomas were included. GATA-3 expression was analyzed by immunohistochemistry and compared to other breast markers [gross cystic disease fluid protein 15 (GCDFP-15) and mammaglobin (MGB)]. RESULTS: GATA-3 was expressed in 82.5% of IBC, predominantly in luminal (93.9%), and lower in non-luminal cancers [59.6% of HER2 overexpressing (HER2-OE) and 38.1% of triple negative breast cancer (TNBC) subtypes]. GATA-3 identified more IBC than GCDFP-15 (23.9%) and MGB (46.6%). However, MGB showed a comparable sensitivity for non-luminal cancers to GATA-3. Combining MGB and GATA-3 improved sensitivity for both HER2-OE (80.8%) and TNBC cases (55.4%). GATA-3 showed a high sensitivity for nodal metastases and distant metastases, with good concordance with primary tumors. GATA-3 was expressed in 1.0% of lung carcinomas, with sensitivity and specificity of 82.5 and 99.0% in differentiating IBC and lung carcinoma. CONCLUSIONS: GATA-3 expression was the highest in luminal breast carcinomas, and showed higher sensitivity than GCDFP-15 and MGB. However, in the poorly differentiated IBC, its utility was still limited. One should be aware of the possible GATA-3 expression in lung carcinomas.

Distinct Tertiary Lymphoid Structure Associations and Their Prognostic Relevance in HER2 Positive and Negative Breast Cancers.

BACKGROUND: The presence of tumor infiltrating lymphocytes (TIL) is associated with favorable prognosis. Recent evidence suggested that not only their density, but also the spatial organization as tertiary lymphoid structures (TLS), play a key role in determining patient survival. MATERIALS AND METHODS: In a cohort of 248 breast cancers, the clinicopathologic association and prognostic role of TLS was examined. RESULTS: Tertiary lymphoid structures were associated with higher tumor grade, apocrine phenotype, necrosis, extensive in situ component, lymphovascular invasion (LVI), and high TIL. For biomarkers, TLS were associated with hormone receptors negativity, HER2 positivity, and c-kit expression. Tertiary lymphoid structures were significantly related to better disease-free survival (DFS) in HER2 positive (HER2+) breast cancers (log-rank = 4.054), which was not dependent on high TIL status. The combined TLS and TIL status was an independent favorable factor associated with DFS in those cases. Interestingly, tumor cell infiltration into the TLS was found in 41.9% of TLS positive cases. It was associated with LVI in HER2 negative (HER2-) TLS positive (particularly estrogen receptor positive [ER+] HER2-) cases. In the ER+ HER2- cases, tumor cell infiltration into TLS was also associated with increased pathologic nodal stage (pN) stage and nodal involvement. CONCLUSION: Tertiary lymphoid structures showed a similar relationship with clinicopathologic features and biomarkers as TIL. The presence of TLS, irrespective of TIL level, could be an important favorable prognostic indicator in HER2+ breast cancer patients. Given the significance of TLS in promoting effective antitumor immunity, further understanding of its organization and induction may provide new opportunities to improve the current immunotherapy strategies. IMPLICATIONS FOR PRACTICE: Despite recent interest on the clinical value of tumor infiltrating lymphocyte (TIL), little was known on the clinical significance on their spatial organization as tertiary lymphoid structures (TLS). Although TLS showed similar relationships with clinicopathologic features and biomarkers as TIL, the prognostic value of TLS, particularly in HER2 positive cancers, was independent of TIL. Moreover, tumor infiltration could be present in TLS which appears to be related to tumor invasion in HER2 negative cancers. Overall, the results demonstrated the additional value for TLS in HER2 cancer subtypes. Further investigations and its standardized evaluation will enhance its use as standard practice.

Expression and Clinical Significance of Herpes Virus Entry Mediator (HVEM) in Breast Cancer.

BACKGROUND: Immune checkpoint blockades are currently actively investigated in invasive breast cancers. Given the complexity of immune regulation, multiple inhibitory molecules within the immune checkpoint framework would be involved in tumor immune escape. Evaluation of the components within the framework is a prerequisite for not only identification of additional treatment targets and optimization of immunotherapeutic strategies but also understanding the prognostic value of these molecules. METHODS AND RESULTS: We examined a recently described component, herpes virus entry mediator (HVEM), in a large cohort of invasive breast cancers using immunohistochemistry, and evaluated its clinical relevance. HVEM expression was associated with aggressive tumor features, namely high grade (p < 0.001), high pT (p = 0.001) and pN stage (p = 0.008), and was most prevalently found in human epidermal growth factor receptor 2-overexpressed subtype (67%). Interestingly, a negative association with programmed death-ligand 1 (p = 0.021) has been observed. The prognostic impact of HVEM depended on the level of tumor-infiltrating lymphocytes (TILs), with the worst outcome occurring in patients with low TIL, HVEM-positive tumors. CONCLUSION: HVEM plays significant oncogenic roles in breast carcinogenesis, and may also be a tumor-specific target.

PD-L1 expression and tumor infiltrating PD-1+ lymphocytes associated with outcome in HER2+ breast cancer patients.

PURPOSE: Clinical trials showing programmed death (PD)-1-PD-ligand 1 (L1) axis as a promising therapeutic target in melanoma and non-small cell lung cancers have made the pathway a focus of recent attention. However, the data regarding PD-L1/PD-1 in breast cancer are inconsistent. Given the heterogeneity of breast cancers, the clinical relevance of PD-L1 and PD-1 tumor infiltrating lymphocytes (TIL) may vary according to subtypes of breast cancer. We aim to investigate PD-L1 expression in a large cohort of breast cancers and analyze its clinico-pathological as well as outcome relationship according to molecular subtypes. Also, we evaluate the relationship of PD-1 TIL and PD-L1 expression with patients' survival, particularly for breast cancers with high TIL. METHODS AND RESULTS: Immunohistochemical analysis of PD-L1 on tissue arrays for 1091 breast cancer patients and PD-1 TIL on 97 whole sections was performed. Associations of PD-L1 with luminal cancers (p < 0.001) and features associated with that subtype [lower histologic grade, absence of necrosis, ER, PR, and AR expression (p < 0.001)] were observed. However, in HER2+ breast cancers, PD-L1 was an independent poor prognostic indicator (DFS: HR = 1.866, p = 0.001; OS: HR = 1.517, p = 0.036). Interestingly, HER2+ cancers showed a lower PD-1 TIL level compared to the other high TIL cases (p = 0.011). Cases with low PD-TIL but high PD-L1 expression showed the worst survival. This could be indicative of an active immune suppression by PD-L1 expression. CONCLUSIONS: Our data showed the relevance of PD-L1 expression in HER2+ breast cancer. A combined evaluation of PD-L1 and PD-1 TIL in the prognosis of breast cancer might also be of value in treatment prediction.

Hyaluronan synthase 2 is an adverse prognostic marker in androgen receptor-negative breast cancer.

AIMS: The important role of hyaluronan synthase 2 (HAS2), an isozyme responsible for hyaluronan synthesis, in cancer has been increasingly recognised. However, only a few studies with inconsistent results have been reported in breast cancers. With a large cohort, we aim to determine the clinical significance of HAS2 in breast cancers. METHODS: We examined HAS2 expression in 1142 breast cancers using immunohistochemistry. RESULTS: HAS2 was associated with both prognostically favourable (androgen receptor (AR), p<0.001) and unfavourable (basal and epithelial mesenchymal transition markers, p≤0.039) biomarkers. In addition, HAS2 showed differential associations with various features and outcome between AR+ and AR- subgroups. HAS2+AR- breast cancers showed significantly worse outcome than other subgroups, and HAS2+AR- subgroup was an independent adverse prognostic factor for disease-free survival (HR 1.309, p=0.046). Interestingly, HAS2 was associated with many poor prognostic features (including higher grade, lymphovascular invasion, basal-like breast cancer subtype, high Ki67 and basal marker expression) only in AR-, but not AR+ breast cancers. CONCLUSIONS: HAS2 has been proposed to be a target for therapeutic intervention in cancer. Our findings suggested a possible antagonistic role of AR pathway on HAS2 function. It will be interesting to further investigate their precise interaction, which may have important implication in HAS2 targeting.