TRPS1 is a promising marker for all subtypes of breast cancer

AIMS

Trichorhinophalangeal syndrome-1 (TRPS1) has been proposed as a novel breast marker with equally high expression in breast cancer (BC) subtypes, making it a useful diagnostic tool. Here, its expression was evaluated alongside other commonly used markers [GATA3, GCDFP15, mammaglobin (MGB) and SOX10] in a large cohort of BCs (n = 1852) and their corresponding nodal metastases. Its usefulness as a diagnostic tool and its correlation with clinicopathological features were assessed.

METHODS AND RESULTS

TRPS1 was expressed at 75.8% overall in the BC cohort, with at least 58% expression among BC subtypes. It was less sensitive than GATA3 for luminal and HER2-overexpressing (HER2-OE) cancers (luminal A: 82 versus 97%; luminal B: 80 versus 95%; HER2-OE: 62 versus 76%), but it was the most sensitive for TNBC (60 versus ≤ 41%). It showed a stable expression in nodal metastases (primary tumour 76 versus nodal metastasis 78%), unlike a reduced nodal expression for GATA3 (86 versus 77%). TRPS1 outperformed GATA3 in detecting non-luminal cancers when paired with other breast markers. TRPS1 and GCDFP15 was the most sensitive combination in TNBC detection, with a 76% detection rate. For TRPS1-negative and GCDFP15-negative TNBCs, SOX10 was more sensitive than GATA3 (29 versus 24%).

CONCLUSIONS

TRPS1 is a highly sensitive marker for all breast cancer subtypes, outperforming GATA3 in non-luminal cancers and displaying the highest sensitivity for TNBC detection when combined with GCDFP15. It is a valuable addition to the breast marker panel for accurate identification of BC.

Subtyping of triple-negative breast cancers: its prognostication and implications in diagnosis of breast origin

BACKGROUND

Triple-negative breast cancer (TNBC) subtyping by gene profiling has provided valuable clinical information. Here, we aimed to evaluate the relevance of TNBC subtyping using immunohistochemistry (IHC), which could be a more clinically practical approach, for prognostication and applications in patient management.

METHODS

A total of 123 TNBC cases were classified using androgen receptor (AR), CD8, Forkhead box C1 protein (FOXC1), and doublecortin-like kinase 1 (DCLK1) into luminal androgen receptor (LAR), basal-like immunosuppressive (BLIS), mesenchymal-like (MES), and immunomodulatory (IM) subtypes. The IM cases were further divided into the IM-excluded and IM-inflamed categories by CD8 spatial distribution. Their clinicopathological and biomarker profiles and prognoses were evaluated.

RESULTS

LAR (28.6%) and MES (11.2%) were the most and least frequent subtypes. The IHC-TNBC subtypes demonstrated distinct clinicopathological features and biomarker profiles, corresponding to the reported features in gene profiling studies. IM-inflamed subtype had the best outcome, while BLIS had a significantly poorer survival. Differential breast-specific marker expressions were found. Trichorhinophalangeal syndrome type 1 (TRPS1) was more sensitive for IM-inflamed and BLIS, GATA-binding protein 3 (GATA3) for IM-excluded and MES, and gross cystic disease fluid protein 15 (GCDFP15) for LAR subtypes.

CONCLUSIONS

Our findings demonstrated the feasibility of IHC surrogates to stratify TNBC subtypes with distinct features and prognoses. The IM subtype can be refined by its CD8 spatial pattern. Breast-specific marker expression varied among the subtypes. Marker selection should be tailored accordingly.

Neutrophil-lymphocyte ratio reflects tumour-infiltrating lymphocytes and tumour-associated macrophages and independently predicts poor outcome in breast cancers with neoadjuvant chemotherapy

AIMS

The neutrophil-lymphocyte ratio (NLR) is a systemic reflection of cancer-associated inflammation and a prognostic marker for breast cancer. For the local tumour microenvironment, tumour-infiltrating lymphocytes (TILs) and tumour-associated macrophages (TAMs) are also highly correlated with breast cancer survival. This study aimed to explore the relationship between the circulating and local immune microenvironment, and to further delineate the prognostic role of NLR in breast cancer patients receiving neoadjuvant chemotherapy (NAC).

METHODS

A cohort of breast cancer patients receiving NAC with subsequent surgery was retrieved. Clinical data were reviewed. Histological slides and CD8 immunohistochemistry from biopsy (pre-chemotherapy) and excision (postchemotherapy) specimens were assessed for TILs and TAMs.

RESULTS

A total of 146 patients were included. There was a significant positive correlation between pre- and postsurgery NLR at a cut-off of 2.6 (median pre-chemotherapy NLR) (P < 0.001). NLR pre-chemotherapy was associated positively with necrosis on biopsy (P = 0.027) and excision (P = 0.021) and TAMs on excision (P = 0.049). NLR 1 year postsurgery was associated with high tumour stage (P = 0.050) and low histological grade (P = 0.008). TIL count was lower in NLR-high cases at almost all time-points by histological assessment and CD8 immunostaining (P < 0.050). In multivariate analysis, postsurgery NLR is an independent predictor for overall survival [OS; hazard ratio (HR) = 9.524, P < 0.001], breast cancer-specific survival (BCSS) (HR = 10.059, P = 0.001) and disease-free survival (DFS; HR = 2.824, P = 0.016).

CONCLUSIONS

The association between NLR with tumour necrosis, TAMs and TILs illustrates an interaction between the circulating and local immune microenvironment. Late NLR is a strong indicator of outcome and may be useful for prognostication and disease monitoring.

Spatial Distribution and Densities of CD103+ and FoxP3+ Tumor Infiltrating Lymphocytes by Digital Analysis for Outcome Prediction in Breast Cancer

BACKGROUND

The evaluation of tumor-infiltrating lymphocytes (TILs) for breast cancer prognosis is now established. However, the clinical value for their spatial distributions of specific immune subsets, namely CD103+ tissue-resident memory T cells FoxP3+ regulatory T ells, have not been thoroughly examined.

METHOD

Representative whole sections of breast cancers were subjected to CD103 and FoxP3 double staining. Their density, ratio, and spatial features were analyzed in tumor area and tumor-stromal interface. Their associations with clinicopathological parameters and patient's prognosis were analyzed.

RESULTS

CD103 TILs were closer to tumor nests than FoxP3 TILs in the tumor-stromal interface. Their densities were associated with high-grade disease, TNBC, and stromal TILs. High stromal FoxP3 (sFoxP3) TILs and close proximity of sCD103 TILs to tumor were independently associated with better survival at multivariate analysis. Subgroup analysis showed the high FoxP3 TILs density associated better survival was seen in HER2-OE and TNBC subtypes while the proximity of CD103 TILs to tumor nests associated better survival was seen in luminal cancers.

CONCLUSION

The prognostic impact of CD103 and FoxP3 TILs in breast cancer depends on their spatial localization. High sFoxP3 TIL density and the lower distance of CD103 TILs from the tumor nests had independent favorable prognostic values.

Urine cytology in the detection of renal cell carcinomas - a territory-wide multi-institutional retrospective review of more than 2 decades

INTRODUCTION

Compared with urothelial lesions of the upper urinary tract, the diagnostic performance of urine cytology in detection of renal cell carcinomas is underreported. This study aims to establish the role of urine cytology in the assessment of renal carcinomas by a multi-institute review of urine cytology from nephrectomy confirmed renal cell carcinomas, referenced against renal urothelial and squamous cell carcinomas.

METHODS

Records of nephrectomy performed from the 1990s to 2020s at three hospitals were retrieved and matched to urine cytology specimens collected within 1 year prior. Patient demographics, specimen descriptors, and histology and staging parameters were reviewed and compared against cytologic diagnoses.

RESULTS

There were 1147 cases of urine cytology matched with renal cell carcinomas, with 666 renal urothelial/squamous carcinomas for comparison. The detection rate for urothelial/squamous (atypia or above [C3+]: 63.1%; suspicious or above [C4+]: 24.0%) were higher than renal cell carcinoma (C3+: 13.1%; C4+: 1.5%) (p < 0.001). The positive rate for upper tract urine exceeded other collection methods at 45.0% (C3+) and 10.0% (C4+) (p < .01). Other factors associated with increased positive rates were male sex, collecting duct carcinoma histology, nuclear grade, and renal/sinus involvement (p < .05). Multivariate analysis revealed additional positive correlations with presence of sarcomatoid tumor cells, lymphovascular invasion, and perinephric fat involvement (p < .05). Larger lesion size and higher urine volume did not improve detection rates (p < .05).

CONCLUSIONS

The detection rate of renal cell carcinomas is suboptimal compared with urothelial carcinomas, although urine samples collected from cystoscopy or percutaneous nephrostomy significantly outperformed voided urine specimens.

Immunocytochemical markers, molecular testing and digital cytopathology for aspiration cytology of metastatic breast carcinoma

Fine-needle aspiration cytology (FNAC) is a versatile diagnostic procedure uniquely suited for tissue biopsy of breast carcinomas and axillary metastases and/or recurrences. With the expanding treatment options and accompanying theragnostic tests, it is crucial to recognize the developments on ancillary testing and digital cytopathology techniques related to aspiration cytology of metastatic breast carcinoma. In this review, we aim to summarize and update the evidence of immunocytochemistry, for the detection of carcinoma cells (epithelial markers), confirmation of breast primary (breast-specific markers), assessment of surrogate immunostains (hormone receptors, ki-67 proliferative index and HER2) and theragnostic biomarkers, with discussion on potential diagnostic pitfalls, followed by the application of molecular tests, and digital cytopathologic techniques for assessing metastatic breast carcinoma in cytology.

Cytomorphological Assessment in Aspirates of Ductal Carcinoma in situ: Correlations with Histopathologic Grade, Architectural Pattern, and Invasion

INTRODUCTION

Fine-needle aspiration biopsy (FNAB) of the breast is an effective and widely adopted diagnostic technique. Histopathologic grading of ductal carcinoma in situ (DCIS) has prognostic significance. In this current study, FNAB of DCIS was reviewed to identify parameters that predict grading, histopathologic architecture, and presence of invasion in DCIS.

METHODS

Aspirates from histopathology-proven cases of DCIS were retrieved and reviewed for cytomorphologic parameters including cellularity, composition, epithelial fragment architecture cellular/nuclear features.

RESULTS

In total 104 aspirates were reviewed. Cytopathologic cellular features - large nuclear size (p = 0.005), prominent nucleoli (p = 0.011), increased nuclear membrane irregularity (p = 0.043), high variation in nuclear size (p = 0.025), and presence of apoptotic figures in epithelial structures (p < 0.001); and background debris (p = 0.033) correlated with a high-grade diagnosis. Cytoplasmic vacuolation (p = 0.034) was seen exclusively in non-high-grade aspirates. Epithelial fragment architecture did not correlate with grading. A predominance (≥50%) of solid aggregates and papillary fragments on FNAB correlated with histopathologically solid (p = 0.039, p = 0.005) and papillary (p = 0.029, < p = 0.001) patterns. No parameter showed correlation with invasion.

CONCLUSION

FNAB is effective in predicting DCIS grading. Epithelial fragment architecture assessment is limited to papillary or solid types, and FNAB cannot predict focal invasion in DCIS.

Detection of early (T1) lung cancers and lepidic adenocarcinomas in sputum and bronchial cytology

BACKGROUND

The lung is an extensively epithelialized organ, producing ample exfoliated material for sputum and bronchial cytology. In view of the updates in the World Health Organization classification of early (T1/≤ 3 cm) lung cancer with respect to adenocarcinomas with lepidic pattern, this study retrospectively reviews sputum and bronchial cytology paired with resection-confirmed lung cancers.

METHODS

A computerized search for all lung resection specimens of carcinomas over a 20-year period was performed. Cytologic diagnoses of corresponding sputum and bronchial cytology were classified into five-tiered categories (C1-insufficient/inadequate, C2-benign, C3-atypia, C4-suspicious and C5-malignant). Reports and slides of the resection specimen were reviewed for reclassification of T1 cancers.

RESULTS

Totally 472 and 383 sputum and bronchial cytology specimens respectively were included. Sensitivity for T1 lesions on sputum cytology were 10.6 %, 2.1 % and 0.5 % at cutoffs of atypia/C3, suspicious/C4 and malignant/C5 categories, lower than bronchial cytology (35.1 %, 15.5 %, 8.1 %; p < 0.001). T1 lesions correlated with lower detection rates, whereas squamous cell carcinoma histology, larger size and bronchial invasion were associated with increased detection rates in sputum and bronchial cytology (p < 0.050). Detection rates for abrasive bronchial cytology (brushing) were overall higher (p = 0.018- < 0.001), but on subgroup comparison, non-abrasive (aspiration, lavage and washing) cytology demonstrated favorable trends (p = 0.063-0.088) in detecting T1 lesions. Adenocarcinomas with lepidic pattern had lower suspicious/C4 (p = 0.040) or above and malignant/C5 (p = 0.019), but not atypia/C3 or above (p = 0.517) rates.

CONCLUSIONS

Most adenocarcinomas with lepidic pattern are only diagnosed as atypia/C3 on cytology. With its modest sensitivity, interpretation of negative and indeterminate cytology results mandates caution.

Application of algorithmic cytomorphological assessment and immunocytochemistry with the international system for reporting serous fluid cytopathology on pericardial fluid cytology

AIMS

The international system for reporting serous fluid cytopathology (ISRSFC) set forth a five-tiered reporting system with comprehensive validation on pleural and peritoneal fluid cytology. An algorithmic approach for cytomorphological assessment and immunocytochemistry was also described in ISRSFC. Limited data on pericardial fluid are supportive but would benefit from further investigation.

METHODS

Consecutive pericardial fluid cytology over a 4-year period was reviewed by multiple board-certified pathologists according to the ISRSFC. Cytomorphology and immunocytochemistry were assessed sequentially, with respective diagnostic performances computed and compared. Literature review was performed.

RESULTS

In total 358 specimens, including 53 with immunocytochemistry available, were reviewed. There were 137 benign and 221 malignant (MAL) cases. The risks of malignancy were 23.5% non-diagnostic (ND), 29.2% negative for malignancy (NFM), 56.0% atypia of undetermined significance (AUS), 82.6% suspicious for malignancy (SFM) and 99.2% (MAL) for cytomorphological assessment, improving to 23.5% (ND), 29.1% (NFM), 56.8% (AUS), 78.9% (SFM) and 99.3% (MAL) incorporating immunocytochemistry. Ten cases (2.8%) received a change in diagnosis after review of immunocytochemistry. All revisions of diagnostic category were appropriate upgrades/downgrades referenced against clinical information. Cytomorphological typing was accurate for adenocarcinoma (n=81/83, 97.6%), while other carcinomas and lymphomas required immunocytochemistry. Certain subcategories within AUS and SFM pertaining to bland indeterminate epithelial cells or mucinous material were not seen for pericardial fluid.

CONCLUSIONS

The ISRSFC shows robust diagnostic performance for pericardial fluid cytology. For pericardial effusion, disease composition and applicable cytological subcategories differ from its peritoneal and pleural counterparts. Incorporating immunocytochemistry by an algorithmic approach improves diagnostic accuracy. Cytomorphology is accurate for identifying adenocarcinomas, but further typing necessitates immunocytochemistry is necessary.

Comprehensive characterization of HER2-low breast cancers: implications in prognosis and treatment

BACKGROUND

HER2-low cancers are heterogeneous with different degrees of HER2 expression and hormone receptor (HR) status. Currently, its analysis is mostly focused on the standard clinic-pathologic features or common biomarkers expression, without considering the heterogeneity within the category. A further characterization and understanding of this cancer subgroup will facilitate its management.

METHODS

A large cohort of HER2-negative cancers (N = 1464) was included. The HER2-low (N = 412) and HER2-zero cancers (N = 1052) were compared and correlated with a comprehensive panel of clinico-pathologic features and biomarker expression according to different HER2 expressions and HR statuses. The prognostic values of these features in HER2-low cancers were also evaluated.

FINDINGS

The characteristics of HER2-low breast cancers, as compared to HER2-zero, varied with the HR status. HER2-low luminal cancers were associated with younger age, larger tumor, high pAKT and high HLA expression. Among TNBCs, opposite trends in age and tumor size were found. Additionally, HER2-low TNBC showed less necrosis, higher pN, lower c-kit and CK14 than HER2-zero cancers. Nonetheless, regardless of HR status, HER2-low status was associated with increased COX2 and AR expression, implicated in the biology of HER2-low cancers. HER2-low cancers showed high expression of HLAs in tumors and PD-L1 in immune cells. In particular, the co-expression of HLAs was found to be associated with better survival in HER2-low cancers.

INTERPRETATION

This study revealed further characteristic of HER2-low breast cancers as compared to HER2-zero cancers, provided further insights into its prognostication and therapeutic strategies.

FUNDING

Health and Medical Research Fund (08190586), Cheng Yue Pui Charity Foundation and CUHK direct grant.

Idiopathic granulomatous mastitis and cystic neutrophilic granulomatous mastitis: two sides of the same coin or distinct entities?

Idiopathic granulomatous mastitis (IGM) is a benign mimic of breast carcinomas. It is defined histologically by the presence of granulomas and inflammation. The closely related cystic neutrophilic granulomatous mastitis (CNGM) shows lipogranulomas, with a reported association with corynebacteria. A large cohort of IGM was reviewed to compare clinical, microbiological and histological features between non-CNGM IGM and CNGM. Cases of IGM were reviewed for histological parameters including the presence of lipogranulomas and composition of inflammatory cells. Clinical data were obtained through hospital records. The cohort included 79 cases, including 51 non-CNGM IGM and 28 CNGM. Comparing non-CNGM IGM and CNGM, there were no differences in clinical or demographical data, other than a younger age of presentation (36.2 vs 41.5 years, p=0.012) for CNGM. Most IGM resolved within the follow-up period (n=57/64, 89.1%), with similar outcomes regardless of treatment (p>0.05). In CNGM, there were more infiltrates of neutrophils (p=0.001), histiocytes (p=0.047), and multinucleated giant cells (p=0.006), but less lymphocytes (p=0.008). Corynebacteria was cultured in two (25%) cases of CNGM, and one non-CNGM IGM (14.3%). Gram-positive bacilli were identified in two cases of CNGM. 'Early' lipogranulomas were observed closely associated to inflamed ducts in three cases of CNGM. Apart from age, there was no distinct clinical or microbiological feature for CNGM. These findings do not support CNGM as a distinct entity. Rather, CNGM-pattern may represent a continuum of IGM, possibly age-related and attributable to ductal inflammation and cystic changes in the breast parenchyma.

DNA methylation age in paired tumor and adjacent normal breast tissue in Chinese women with breast cancer

BACKGROUND

Few studies have examined epigenetic age acceleration (AA), the difference between DNA methylation (DNAm) predicted age and chronological age, in relation to somatic genomic features in paired cancer and normal tissue, with less work done in non-European populations. In this study, we aimed to examine DNAm age and its associations with breast cancer risk factors, subtypes, somatic genomic profiles including mutation and copy number alterations and other aging markers in breast tissue of Chinese breast cancer (BC) patients from Hong Kong.

METHODS

We performed genome-wide DNA methylation profiling of 196 tumor and 188 paired adjacent normal tissue collected from Chinese BC patients in Hong Kong (HKBC) using Illumina MethylationEPIC array. The DNAm age was calculated using Horvath's pan-tissue clock model. Somatic genomic features were based on data from RNA sequencing (RNASeq), whole-exome sequencing (WES), and whole-genome sequencing (WGS). Pearson's correlation (r), Kruskal-Wallis test, and regression models were used to estimate associations of DNAm AA with somatic features and breast cancer risk factors.

RESULTS

DNAm age showed a stronger correlation with chronological age in normal (Pearson r = 0.78, P < 2.2e-16) than in tumor tissue (Pearson r = 0.31, P = 7.8e-06). Although overall DNAm age or AA did not vary significantly by tissue within the same individual, luminal A tumors exhibited increased DNAm AA (P = 0.004) while HER2-enriched/basal-like tumors exhibited markedly lower DNAm AA (P = < .0001) compared with paired normal tissue. Consistent with the subtype association, tumor DNAm AA was positively correlated with ESR1 (Pearson r = 0.39, P = 6.3e-06) and PGR (Pearson r = 0.36, P = 2.4e-05) gene expression. In line with this, we found that increasing DNAm AA was associated with higher body mass index (P = 0.039) and earlier age at menarche (P = 0.035), factors that are related to cumulative exposure to estrogen. In contrast, variables indicating extensive genomic instability, such as TP53 somatic mutations, high tumor mutation/copy number alteration burden, and homologous repair deficiency were associated with lower DNAm AA.

CONCLUSIONS

Our findings provide additional insights into the complexity of breast tissue aging that is associated with the interaction of hormonal, genomic, and epigenetic mechanisms in an East Asian population.

Bronchial cytology of pulmonary adenoid cystic carcinoma - A multi-institute series with emphasis on immunocytochemistry

BACKGROUND

Pulmonary adenoid cystic carcinoma (AdCC) is a central and superficial primary lung neoplasm, well-suited for sampling by bronchial cytology. This study aims to review the cytologic features of pulmonary AdCC on bronchial cytology, and to report an experience of applying immunocytochemistry on this rare entity.

METHODS

A multi-institute review of bronchial cytology specimens from histologically proven pulmonary AdCCs was performed. Published cases of bronchial cytology of pulmonary AdCC were reviewed. The cytologic features and immunocytochemical profile for pulmonary AdCC was summarized and compared with pertinent differentials.

RESULTS

A total of 16 specimens from eight patients were retrieved. The initial cytologic diagnoses were negative (n = 7), atypia (n = 6), suspicious (n = 2) and AdCC (n = 1). Retrospective review showed eight bronchial cytology specimens (including five cases of atypia) with tumor cells present. The tumor cells displayed small basaloid nuclei with occasional small nucleoli, mild nuclear atypia, and scanty cytoplasm. Architectural patterns observed included clusters, tubules, solid sheets, three-dimensional balls, papillary-like fronds, and complex cribriform structures. Basement-membrane-like material, free or associated with tumor cells, were seen in all cases. Immunocytochemistry was performed in one specimen. MYB was positive. TTF-1, synaptophysin and chromogranin were negative. Epithelial and basal markers demonstrated a dual cell population. Literature review yielded 28 cases. Cytologic features described were similar except for cytoplasmic vacuolation in one case.

CONCLUSION

Basement membrane-like material is specific for AdCC. MYB positivity, TTF-1 and neuroendocrine marker negativity, support a diagnosis of AdCC. Other immunocytochemistry and cytologic features overlap significantly with adenocarcinoma and small cell carcinoma of lung.

Number needed to diagnose in malignant ascites - effects of volume, repeating collection, and primary malignancy on diagnostic performance in peritoneal fluid cytology

Introduction Volume recommendations of 80-200ml have been proposed for peritoneal fluid cytology. While cut-offs are impractical when volume is limited by the amount present and disease factors, collections, however, can be repeated. This study addresses adequacy and number needed to diagnose by comparing diagnostic agreement to volumes in single specimens, total volumes collected daily, and within admissions. The diagnostic yield of repeating collection within a single day, admission, and throughout admissions of a patient's lifetime was also investigated. Methods Peritoneal fluid cytology specimens over a 27-year period were retrieved, and matched by collection date, admission number and patient number. Case notes were reviewed to establish all cases of malignant ascites. Results In total, 19,392 specimens from 14,327 admissions and 11,089 patients were retrieved, with 1,531 patients confirmed with malignant ascites. Agreements between cytologic diagnoses within the same day and admission were high (κ>0.8). Fluid volume increased with grade of cytologic diagnosis (p<0.001), and greater volume was associated with higher discordance (p<0.05). Specimens of 60-100ml showed the best diagnostic concordance. To achieve a 99.5% diagnostic rate, three sequential aliquots, collections from two different days in an admission, or three admissions within a lifetime is required. The diagnostic yield of one aliquot within batches from the same day was only 88.9%. Gastrointestinal (p=0.040), gynecologic (p=0.005) and lung (p<0.001) malignancies required the least repeats for diagnosis. Conclusions Omission of any fluid from laboratory submission is strongly discouraged. As a simple rule, three repeats are necessary for excluding malignant ascites.

WT1 as a myoepithelial marker: a comparative study of breast, cutaneous, and salivary gland lesions

WT1 immunostain is expressed in various benign and malignant neoplasms, as well as normal myoepithelial cells. WT1 shows differential expression in non-neoplastic, benign, and malignant neoplastic myoepithelial cells of the salivary gland. In this study, WT1 immunostain and other myoepithelial markers were compared to investigate the value of WT1 as a myoepithelial marker, and to delineate the expression profile of WT1 in nonsalivary gland myoepithelial cells. WT1, p63, and calponin immunostains were performed on normal and lesional tissues from the breast (adenosis, sclerosing adenosis, lactating adenoma, nipple adenoma, tubular adenoma, adenomyoepithelioma, and adenoid cystic carcinoma [ACC]), skin (cutaneous mixed tumor, hidradenoma, spiradenoma, and ACC), and salivary gland (pleomorphic adenoma and ACC). The stained slides were digitized and orientated with H&E images and assessed simultaneously using QuPath. A total of 129, 58, and 56 breast, cutaneous, and salivary gland lesions, respectively, were included. There was poor agreement between WT1-p63 and WT1-calponin (κ < 0.1) in all organs, with absence of WT1 expression in normal salivary gland myoepithelium and most ACCs. There were no significant differences in WT1 expression in myoepithelial cells in normal breast tissue and benign breast neoplasms. Compared to pleomorphic adenomas, cutaneous mixed tumors showed lower WT1 expression (P < .001). WT1 is a less sensitive myoepithelial marker than calponin and p63. However, its unique pattern of expression in salivary gland primary for pleomorphic adenomas/cutaneous mixed tumor can favor a diagnosis of benign salivary gland tumors, particularly in small biopsy specimens.

Anatomical site and size of sentinel lymph node metastasis predicted additional axillary tumour burden and breast cancer survival

AIMS

Sentinel lymph node (SLN) biopsy is the current standard assessment for tumour burden in axillary lymph node (ALN). However, not all SLN+ patients have ALN metastasis. The prognostic implication of SLN features is not clear. We aimed to evaluate predictive factors for ALN metastasis and the clinical value of SLN features.

METHODS AND RESULTS

A total of 228 SLN+ and 228 SLN- (with matched year and grade) cases were included. Clinicopathological features in SLN, ALN and primary tumours, treatment data and survival data were analysed according to ALN status and outcome. Except for larger tumour size and the presence of LVI (both P < 0.001), no significant differences were found in SLN- and SLN+ cases. Only 31.8% of SLN+ cases with ALN dissection had ALN metastasis. The presence of macrometastases (MaM), extranodal extension (ENE), deeper level of tumour invasion in SLN and more SLN+ nodes were associated with ALN metastasis (P ≤ 0.025). Moreover, isolated tumour cells (ITC) and level of tumour invasion in SLN were independent adverse prognostic features for disease-free survival and breast cancer-specific survival, respectively. Interestingly, cases with ITC located in the subcapsular region have better survival than those in cortex (OS: χ²  = 4.046, P = 0.044).

CONCLUSIONS

Our study identified features in SLN, i.e. the level of tumour invasion at SLN and tumour size in SLN as useful predictors for both ALN metastasis and breast cancer outcome. The presence of ITC, particularly those with a deeper invasion in SLN, portended a worse prognosis. Proper attention should be taken for their management.

Marker assessments in ER-positive breast cancers: old markers, new applications?

Evaluation of oestrogen receptor (ER) expression by immunostaining is essential in the pathological assessment of breast cancer. Its expression is intercorrelated with clinicopathological features, molecular typing, and treatment selection. The development of novel therapeutic agents related to ER status, the recent ASCO introduction of an ER-low positive category of breast cancers, and the ever-increasing plethora of diagnostic and theragnostic markers call for a timely update. In this article we aim to review the clinicopathological features of ER-positive breast cancers, with an emphasis on ER-low positive breast cancers, and a focus on updating the (i) assessment, reporting and interpretation of ER immunohistochemical (IHC) staining, (ii) correlations of ER status with other diagnostic and theragnostic markers, and (iii) implications for treatment selection and response. In the face of the developments in IHC and molecular techniques and targeted therapy, ER immunostaining is still expected to remain as the core component of prognostic and theragnostic assessment of breast cancers.

An international unified approach to reporting and grading invasive breast cancer. An overview of the International Collaboration on Cancer Reporting (ICCR) initiative

Standardised reporting of breast cancer key pathology data has become the norm in some parts of the world, but are based on national or regional guidelines that differ in certain aspects, resulting in divergent reporting practices and a lack of comparability of data internationally. The International Collaboration on Cancer Reporting (ICCR), a global alliance of major (inter-)national pathology and cancer organizations, have recently produced a new international dataset for the pathology reporting of breast cancer, including resection specimens with invasive cancer and ductal carcinoma in situ (DCIS) of the breast. This initiative aims at providing an international unified approach to reporting cancer. The guidance was prepared by an international expert panel consisting of experienced breast pathologists, a surgeon, and an oncologist. The dataset includes core (essential) and noncore (optional) data items based on a critical review and discussion of current evidence. Commentary is provided for each data item to explain the rationale for selection, its clinical relevance, and to highlight potential areas of disagreement or lack of evidence, in which case a consensus position was formulated. The process concludes with international public consultation, before ratification and publication on the free open access ICCR website, with a synoptic reporting guide. The key aim is to promote high-quality, standardised pathology reporting that can be used worldwide. Histological grade, tumour size, and oestrogen receptor status are used in this article to illustrate this process and the detail provided to support its inclusion.

An update on the pathological classification of breast cancer

Breast cancer (BC) is a heterogeneous disease, encompassing a diverse spectrum of tumours with varying morphological, biological, and clinical phenotypes. Although tumours may show phenotypic overlap, they often display different biological behaviour and response to therapy. Advances in high-throughput molecular techniques and bioinformatics have contributed to improved understanding of BC biology and refinement of molecular taxonomy with the identification of specific molecular subclasses. Although the traditional pathological morphological classification of BC is of paramount importance and provides diagnostic and prognostic information, current interest focusses on the use of a single gene and multigene assays to stratify BC into distinct groups to guide decisions on systemic therapy. This review considers approaches to the classification of BC, including their limitations, and with particular emphasis on the fundamental role of morphology in establishing an accurate diagnosis of primary invasive carcinoma of breast origin. This forms the basis for further morphological characterization and for all other approaches to BC classification that are used to provide prognostic and therapeutic predictive information.

Artificial intelligence in breast cancer histopathology

This is a review on the use of artificial intelligence for digital breast pathology. A systematic search on PubMed was conducted, identifying 17,324 research papers related to breast cancer pathology. Following a semimanual screening, 664 papers were retrieved and pursued. The papers are grouped into six major tasks performed by pathologists-namely, molecular and hormonal analysis, grading, mitotic figure counting, ki-67 indexing, tumour-infiltrating lymphocyte assessment, and lymph node metastases identification. Under each task, open-source datasets for research to build artificial intelligence (AI) tools are also listed. Many AI tools showed promise and demonstrated feasibility in the automation of routine pathology investigations. We expect continued growth of AI in this field as new algorithms mature.

Spindle Cell Lesions of the Breast: A Diagnostic Algorithm

CONTEXT.—

Spindle cell lesions of the breast represent a broad spectrum of entities, ranging from nonneoplastic reactive conditions to high-grade malignant tumors. The wide range makes breast spindle cell lesions a diagnostic pitfall.

OBJECTIVE.—

To review the classification of spindle cell lesions of the breast, including clinical features, morphologic characteristics, and the role of immunohistochemistry as well as molecular tools in assisting the differential diagnosis. A diagnostic algorithm will be proposed.

DATA SOURCES.—

Literature and personal experience are the sources for this study.

CONCLUSIONS.—

Spindle cell lesions of the breast can be classified as biphasic or monophasic, with the former including both spindle cell and epithelial components, and the latter including only spindle cell elements. Each category is further subclassified as low or high grade. In the biphasic low-grade group, fibroadenoma and benign phyllodes tumor are the most common lesions. Other uncommon lesions include hamartoma, adenomyoepithelioma, and pseudoangiomatous stromal hyperplasia. In the biphasic high-grade group, borderline/malignant phyllodes tumor and biphasic metaplastic carcinoma are the main lesions to consider. In the monophasic low-grade group, reactive spindle cell nodule, nodular fasciitis, myofibroblastoma, fibromatosis, and fibromatosis-like metaplastic carcinoma have to be considered. In the monophasic high-grade group, the possible lesions are monophasic spindle cell metaplastic carcinoma, primary breast sarcoma, and metastases. Awareness of the clinical history and careful evaluation of any epithelial differentiation (with a large immunohistochemical panel) are crucial in the distinction.

Update on triple-negative breast cancers - highlighting subtyping update and treatment implication

Triple-negative breast cancer (TNBC) remains a major challenge in breast cancer management. Continuing research in the past years aimed at understanding the biology of this tumour and developing more effective therapeutic options. It is now clear that TNBC is vastly heterogeneous with diverse histological, molecular, immunological profiles and clinical differences. Current evidence suggested the existence of at least four predominant subtypes based on expression profiling across studies. These subtypes exhibited specific genomic alterations and tumour microenvironment. Subtype-specific therapeutic strategies were identified. Recognising these subtypes allows not only an improved prognostication but also a better treatment decision. Herein, we provide an overview of the recent findings on TNBC heterogeneity at different levels and corresponding subtyping. The characteristic of subtypes and the implication of these subtypings in therapeutic approaches are also discussed.

A comparative study of diagnostic accuracy in 3026 pleural biopsies and matched pleural effusion cytology with clinical correlation

BACKGROUND

Pleural effusion can be caused by a wide range of benign and malignant conditions. Pleural biopsy and effusion cytology represent two key methods of pathological diagnosis. To compare the performance these two methods, a large cohort of matched pleural biopsy and effusion cytology with clinical follow-up was reviewed.

METHODS

Pleural biopsies and effusion cytology specimens over a period of 18 years were retrieved. Cytology specimens collected within 7 days of pleural biopsy were matched. Reports were reviewed, and the cause for pleural effusion was determined by hospital disease coding and clinical data.

RESULTS

Totally, 3026 cases were included. The leading cause of benign effusion was tuberculosis (n = 650). Malignant pleural effusion (MPE) was more common in older females (p < 0.001) and mostly due to lung cancer (n = 959), breast cancer (n = 64), and mesothelioma (n = 48). The inadequate/insufficient (B1/C1) rate of biopsy was higher than cytology (15.6% vs. 0.3%) but the rates for other diagnostic categories were similar. Biopsy and cytology showed a correlation coefficient of 0.315, improving to 0.449 when inadequate/insufficient (B1/C1) cases were excluded. The ROM for benign cytology (C2) was lower than biopsy (B2) (p < 0.001). Compared with biopsy, the diagnostic accuracy was higher in cytology overall and for metastatic carcinomas (p < 0.001) but lower for hematolymphoid malignancies (p = 0.014) and mesotheliomas (p = 0.002).

CONCLUSIONS

These results suggest that effusion cytology may be better for confirming benignity and diagnosing carcinomatous MPE. In these cases, pleural biopsy may be withheld to reduce procedural risks. However, for suspected hematolymphoid malignancies and mesothelioma, biopsy should be considered.

Tubular Adenomas of the Breast Are Cytologically Distinct from Fibroadenomas

<b><i>Introduction:</i></b> Increasing molecular evidence indicates that tubular adenoma of the breast is distinct from fibroepithelial lesions, leading to its reclassification as an epithelial tumor in the 5th World Health Organization classification of tumors of the breast. However, tubular adenoma remains poorly characterized on fine-needle aspiration cytology (FNAC) and often not distinguished from fibroadenomas. In this study, the largest cohort, to date, of histologically confirmed aspirates of tubular adenomas were reviewed and compared with aspirates of fibroadenomas. Findings from this study further define the cytological features of tubular adenoma and allow differentiation from fibroadenoma. <b><i>Methodology:</i></b> Aspirates of histologically confirmed tubular adenomas were reviewed for features of the background, myoepithelial, epithelial, and stromal components and then compared to a cohort of aspirates of fibroadenomas. <b><i>Results:</i></b> Totally, 43 (tubular adenoma) and 94 (fibroadenoma) aspirates were included. Tubular adenomas displayed moderate epithelial cellularity with high cohesiveness, with stromal fragments containing epithelium. Tubules are more common in tubular adenomas (<i>p</i> = 0.009) and “tubular fragments” (tissue fragments containing multiple tubular structures with/without stroma) is a pathognomonic feature of tubular adenoma (<i>p</i> &#x3c; 0.001). Calcification and fibrocystic changes were variably seen (4.65–13.5%) but without difference to fibroadenomas (<i>p</i> &#x3e; 0.05). Cytomorphologically malignant features and mitoses were absent in all aspirates of tubular adenoma. Presence of tubules and stromal fragments were independent factors associated with tubular adenomas, whereas a predominance of large epithelial fragments and naked stromal fragments were associated with fibroadenomas. <b><i>Conclusion:</i></b> Tubular adenomas are not only histologically and molecularly separate from fibroepithelial lesions but also a distinct entity on FNAC.

Papillary lesions of the breast - review and practical issues

Papillary lesions of the breast represent a heterogeneous group of neoplasm featuring fibrovascular cores covered by epithelial cells with or without intervening myoepithelial cells. According to the World Health Organization classification of breast tumors, papillary lesions of the breast are further classified into intraductal papilloma (including intraductal papilloma with atypical ductal hyperplasia /ductal carcinoma in situ), papillary ductal carcinoma in situ, encapsulated papillary carcinoma, solid papillary carcinoma (in situ and invasive) and invasive papillary carcinoma. The overlapping morphological features and immunohistochemical profiles make accurate diagnosis of breast papillary lesion a challenge for pathologists. In this review, the morphological and relevant immunohistochemical features of papillary lesions are discussed, with further emphasis on some commonly encountered practical diagnostic issues. A simple diagnostic algorithm will be established. The relevant molecular characteristics will be discussed as well.

Analysis of recurrent molecular alterations in phyllodes tumour of breast: insights into prognosis and pathogenesis

Phyllodes tumour (PT) of breast is a rare biphasic neoplasm. Recent next generation sequencing analyses had revealed novel genetic alterations in PT but lacked a further characterisation of their relationship to different PT features and outcome. Here, using targeted sequencing, we examined a panel of 90 recurrently altered or cancer related genes in 88 PT samples (including 49 benign, 25 borderline and 14 malignant PT). Twenty-three genes showed alterations in at least 8.0% of cases. Alterations were significantly higher with an increasing grade of PT (p=0.033), particularly for copy number alterations. The top ten alterations were TERT promoter (58.0%), MED12 (53.4%), RARA (22.8%), FLNA (19.3%), SETD2 (15.9%), SYNE1 (18.2%), PCLO (15.9%), KMT2D (14.3%), CDKN2A (15.9%) and DNAH11 (14.8%). Alterations in CDKN2A/B, EGFR, TP53, PIK3CA, PTEN and ARID1B (p≤0.039) were associated with a higher grade. Analysing alterations based on common pathways indicated a significant correlation of cell cycle pathway and epigenetic alterations with a higher PT grade (p=0.036 and 0.075 respectively). Interestingly, recurrences were not correlated with tumour grade, but related to the presence of RARA mutation (p=0.011) and the absence of alterations in epigenetic pathway (p=0.031). Analysis of synchronous pair of PT showed more differences in gene mutations with divergent MED12 mutation. By contrast, the recurrent samples showed similar genetic alterations as the primary tumours. In summary, we characterised genetic alterations in PTs of different grades and confirmed the recurrent alterations observed in earlier studies. In addition, current data implicated the roles of cell cycle, epigenetic and RARA changes in PT recurrence and tumourogenesis.

Associations between Preserved foods and Breast Cancer Risk in Hong Kong Chinese Women

Preserved food such as cured foods may contain nitrate and nitrite that may contribute to the breast cancer development. Evidence on the associations between these preserved food intakes and risk of breast cancer is sparse. This study aimed to examine the associations between preserved foods (i.e. cured meat, pickled vegetables, canned meat, canned fruit/vegetables) and breast cancer risk in Hong Kong Chinese women. A total of 1307 breast cancer cases and 1050 age-matched controls were recruited from three hospitals during 11/2011-01/2018. We used a standardized questionnaire to collect information on dietary factors including preserved foods. Unconditional multiple logistic regression was performed to calculate the adjusted odds ratio(AOR) of breast cancer in relation to preserved food with adjustment of potential confounders. We further performed stratified analysis according to the breast cancer biology subtypes. We found that cured meat consumption was significantly associated with the risk of breast cancer [AOR=1.32, 95% confidence interval 95%CI)=1.06-1.64]. Compared to no cured meat consumption, cured meat intake {greater than or equal to} once per week was associated with an AOR of 2.66 (95%CI=1.38-5.35). Women with canned fruit/vegetable {greater than or equal to} consumption once per week had a higher risk of breast cancer (OR=1.19, 95%CI=1.00-1.41), particularly for the HER2-positive subtypes, but it became borderline after adjustment of confounders. Our study reveals a positive association between consumption of cured meat and breast cancer risk in Chinese population. Cured meat intake might be a potential novel risk factor for breast cancer but this would have to be confirmed by large prospective cohort studies.

Fine-needle aspiration cytology of metastatic carcinomas with papillary architecture: a systemic assessment of clinical, cytologic and immunohistochemical parameters

BACKGROUND

Papillary structures are frequently encountered in metastatic carcinomas from various organs and tumors of different histotypes. This study aims to investigate the predictive value of fine-needle aspiration cytology (FNAC), immunohistochemistry (IHC) and clinical parameters in assessment of primary sites of metastatic carcinomas with papillary architecture.

METHODS

FNAC of metastatic carcinomas with papillary architecture were evaluated for overall cellularity, epithelial cohesion, background features, architecture of papillae, cytology and IHC. The corresponding clinical information were also reviewed.

RESULTS

Totally 130 cases were included. The most common primaries were thyroid (38.5%), lung (30.8%) and gynecological organs (22.3%) with the remainders being pancreaticobiliary, urothelial, colorectal, and esophageal. Age (p=.039), biopsy site (p<.001) and laterality (p=.006) correlated with primary site. Papillary structures were confirmed on biopsy/excision of most cases (n=85/87, 97.7%). Thyroid primaries demonstrated broad papillary stalks, thin lining epithelium, fewer epithelial polymorphs, and presence of background giant cells and histiocytes (p=.021-<.001). Low-grade cytologic features, nuclear grooves and inclusions (p<.001) were seen in thyroid primaries. High-grade features (p<.001-0.49), multinucleated tumor cells, apoptotic bodies and mitoses (p<.001-0.49) were more common in lung/gynecological primaries. Multivariate analysis identified nuclear/cytoplasmic ratio, chromatin character, presence of nuclear groove and mitosis as independent features (p=0.001-.024). TTF1/TGB/PAX8 panel demonstrated good agreement with cytologic assessment and primary site.

CONCLUSION

Papillary structures and cytologic features are reproducible in FNACs of metastases and corresponding primaries. Cytologic features, IHC and clinical information are invaluable in determining the primary site.

Comparison of somatic mutation landscapes in Chinese versus European breast cancer patients

Recent genomic studies suggest that Asian breast cancer (BC) may have distinct somatic features; however, most comparisons of BC genomic features across populations did not account for differences in age, subtype, and sequencing methods. In this study, we analyzed whole-exome sequencing (WES) data to characterize somatic copy number alterations (SCNAs) and mutation profiles in 98 Hong Kong BC (HKBC) patients and compared with those from The Cancer Genome Atlas of European ancestry (TCGA-EA, N = 686), which had similar distributions of age at diagnosis and PAM50 subtypes as in HKBC. We developed a two-sample Poisson model to compare driver gene selection pressure, which reflects the effect sizes of cancer driver genes, while accounting for differences in sample size, sequencing platforms, depths, and mutation calling methods. We found that somatic mutation and SCNA profiles were overall very similar between HKBC and TCGA-EA. The selection pressure for small insertions and deletions (indels) in GATA3 (false discovery rate (FDR) corrected p < 0.01) and single-nucleotide variants (SNVs) in TP53 (nominal p = 0.02, FDR corrected p = 0.28) was lower in HKBC than in TCGA-EA. Among the 13 signatures of single-base substitutions (SBS) that are common in BC, we found a suggestively higher contribution of SBS18 and a lower contribution of SBS1 in HKBC than in TCGA-EA, while the two APOBEC-induced signatures showed similar prevalence. Our results suggest that the genomic landscape of BC was largely very similar between HKBC and TCGA-EA, despite suggestive differences in some driver genes and mutational signatures that warrant future investigations in large and diverse Asian populations.

OUP accepted manuscript

Background

PD-L1 has been used as a biomarker to select patients for treatment of PD-1/PD-L1 inhibitors.

Materials and Methods

In this study, we assessed the clinicopathological features of breast cancers that are associated with PD-L1 expression, as well as its relationship with other immune components and its prognostic significance.

Results

Totally 1752 cases were included in this cohort. PD-L1 expression in tumor-infiltrating immune cells (PD-L1-IC) expression and in tumor cells (PD-L1-TC) expression were identified in 34.2% and 10.1% of cases, respectively, and they showed a positive correlation with higher tumor grade, morphological apocrine features, presence of necrosis, and higher stromal tumor-infiltrating lymphocytes (sTIL). PD-L1-IC and PD-L1-TC expression correlated positively with each other, and both of them were negatively associated with estrogen receptor and progesterone receptor and positively associated with Ki67, HER2, EGFR, p63, and p-cadherin. In survival analysis, PD-L1-IC expression was associated with better disease-free survival (DFS) and breast cancer-specific survival (BCSS) in HER2-overexpressed (HER2-OE) cancers and high–grade luminal B cancers. In triple–negative breast cancers (TNBC) and HER2–OE cancers, compared with sTIL low PD-L1-IC negative cases, sTIL high cases showed significantly better DFS independent of PD-L1-IC status. sTIL low PD-L1-IC positive cases also demonstrated a better DFS in HER2–OE cancers. In high–grade luminal B cancers, sTIL high PD-L1-IC positive cases showed the best BCSS.

Conclusion

The data suggested that the combining analysis of sTIL and PD-L1-IC expression refined the prognostication of breast cancer subtypes. Cases with high TIL and PD-LI-IC expression appear to be more immune active.

Molecular analysis of TCGA breast cancer histologic types

Breast cancer is classified into multiple distinct histologic types, and many of the rarer types have limited characterization. Here, we extend The Cancer Genome Atlas Breast Cancer (TCGA-BRCA) dataset with additional histologic type annotations, in a total of 1063 breast cancers. We analyze this extended dataset to define transcriptomic and genomic profiles of six rare special histologic types: cribriform, micropapillary, mucinous, papillary, metaplastic, and invasive carcinoma with medullary pattern. We show the broader applicability of our constructed special histologic type gene signatures in the TCGA Pan-Cancer Atlas dataset with a predictive model that detects mucinous histologic type across cancers of other organ systems. Using a normal mammary cell differentiation score analysis, we order histologic types into a continuum from stem cell-like to luminal progenitor-like to mature luminal-like. Finally, we classify TCGA-BRCA into 12 consensus groups based on integrated genomic and histological features. We present a rich openly accessible resource of histologic and genomic characterization of TCGA-BRCA to enable studies of the range of breast cancers.

Tumor Microenvironment in Breast Cancer-Updates on Therapeutic Implications and Pathologic Assessment

The tumor microenvironment (TME) in breast cancer comprises local factors, cancer cells, immune cells and stromal cells of the local and distant tissues. The interaction between cancer cells and their microenvironment plays important roles in tumor proliferation, propagation and response to therapies. There is increasing research in exploring and manipulating the non-cancerous components of the TME for breast cancer treatment. As the TME is now increasingly recognized as a treatment target, its pathologic assessment has become a critical component of breast cancer management. The latest WHO classification of tumors of the breast listed stromal response pattern/fibrotic focus as a prognostic factor and includes recommendations on the assessment of tumor infiltrating lymphocytes and PD-1/PD-L1 expression, with therapeutic implications. This review dissects the TME of breast cancer, describes pathologic assessment relevant for prognostication and treatment decision, and details therapeutic options that interacts with and/or exploits the TME in breast cancer.

The International Academy of Cytology Yokohama System for Reporting Breast Cytopathology showed improved diagnostic accuracy

BACKGROUND

The aim of the International Academy of Cytology Yokohama System for Reporting Breast Fine Needle Aspiration Biopsy Cytopathology is to improve cytology practice. This study assessed cytologic diagnoses made with the system and its efficacy when it was applied by pathologists with different levels of experience.

METHODS

In all, 1080 cases of breast fine-needle aspiration biopsy (FNAB) over a period of 16 years were reviewed and reclassified with the system. The category distribution and the diagnostic performance were compared with the original diagnoses. The concordance rates for diagnoses from pathologists with different levels of experience were also determined.

RESULTS

The distribution of cytologic diagnoses made with the system was as follows: 11.7% were insufficient, 56.6% were benign, 20.1% were atypical, 6.1% were suspicious for malignancy, and 5.6% were malignant. The rates for the insufficient and atypical categories were lower than the original diagnosis rates (13.1% and 23.8%, respectively). Overall, 120 cases (11.1%) were recategorized. Among those recategorized as benign, suspicious, or malignant with follow-up data, 96.7% were correctly reclassified. A significant improvement in diagnostic performance was found with the system (P < .001). Such improvement was also seen in problematic breast lesions, including fibroepithelial lesions, papillary lesions, and low-grade carcinomas. Pathologists with intermediate experience showed a higher concordance with an expert pathologist in the diagnoses than those with short experience (κ, 0.838 vs 0.634).

CONCLUSIONS

The system effectively categorized the diagnoses, and the diagnostic performance of FNAB reporting was improved. The structured reporting also enhanced the reproducibility of reporting by pathologists with intermediate experience and, to some extent, those with short experience.

An Evaluation of Clinicopathological Correlation and Outcome of Human Epidermal Growth Factor Receptor 2 Subgroups Reclassified According to the Latest ASCO/CAP Guideline

BACKGROUND

The latest American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guideline has updated the interpretation of uncommon human epidermal growth factor receptor 2 (HER2) in situ hybridization (ISH) patterns (groups 2-4) with concomitant HER2 immunohistochemistry, leading to changes in the diagnosis of these subgroups. We sought to assess the clinicopathological features and outcomes in these subgroups in detail with our local cohort.

PATIENTS AND METHODS

Clinicopathologic features of groups 2 to 4 were compared to the typical amplified group (group 1: HER2/CEP17 ≥ 2, HER2 ≥ 4) and non-amplified group (group 5: HER2/CEP17 < 2, HER2 < 4).

RESULTS

Group 2 (HER2/CEP17 ≥ 2, HER2 < 4) cases showed lower Ki67 expression and grade (P ≤ .002) than group 1 but no differences compared with group 5. Group 4 (HER2/CEP17 < 2, HER2 = 4-6) cases were associated with less necrosis, more estrogen receptor positivity, lower grade, more nodal metastases, and more special histotypes (P ≤ .037) than group 1, but higher grade and more nodal metastases (P ≤ .021) than group 5. Except for presenting as a larger tumor and of special histotypes, group 3 (HER2/CEP17 < 2, HER2 ≥ 6) cases showed no other significant differences from group 1, but were of higher grade and Ki67 level than groups 2, 4, and 5. Group 4, similar to group 5, showed worse survival than group 1 (disease-free survival: log-rank = 5.547, P = .019; overall survival: log-rank = 4.678, P = .031). The rate of relapse was similar in group 4 with and without anti-HER2 therapy, albeit with limited cases.

CONCLUSION

Our findings indicate more similarities among groups 2, 4, and 5 than between groups 1 and 3, supporting the HER2 categorization in the latest guideline. Additional studies may be warranted to assess the outcomes of these patients with different management approaches.

Clinicopathologic and genetic features of metaplastic breast cancer with osseous differentiation: a series of 6 cases

AIMS

Metaplastic breast cancer (MBC) comprises a heterogeneous group of tumors, of which MBC with osseous differentiation (MBC-OD) is extremely rare that only few cases have been reported. This study aimed to present the clinicopathologic and molecular features of MBC-OD.

METHODS

We collected 6 cases of MBC-OD from five different centers and described its clinicopathologic and molecular characteristics based on the next-generation sequencing. Another 11 cases from the literature were also reviewed to better characterize the tumor.

RESULTS

The tumor primarily showed an osteosarcoma-like appearance, which composed of high cellularity with spindle cells and osteoblast-like cells producing coarse lace-like neoplastic bone (4/6) or osteoid matrix (6/6). 55 somatic mutations including 39 missenses (70.9%), 9 frameshifts (16.4%), 3 splice sites (5.5%), 3 in-frame InDels (5.5%) and 1 nonsense (1.8%) were identified. TP53 was the most frequently mutated genes (5/6, 83.3%), followed by RB1 (3/6, 50.0%), BCOR (2/6, 33.3%), MED12 (2/6, 33.3%), PIK3CA (2/6, 33.3%), and TET2 (2/6, 33.3%). Genetic alterations suggesting therapies with clinical benefit, including mTOR inhibitors, tyrosine kinase inhibitors (TKI), and poly-ADP ribose polymerase inhibitor (PARPi), were observed in five cases. The median follow-up was 21 months (range, 3-80 months). Local recurrence was observed in two cases and three patients displayed distant metastasis. Two patients died of the disease at 3 months and 7 months, respectively.

CONCLUSIONS

Based on this series, MBC-OD is a highly aggressive breast tumor with osteosarcoma-like morphology and a high incidence of recurrent disease showing specific genetic profiles.

SETD2 alterations and histone H3K36 trimethylation in phyllodes tumor of breast

PURPOSE

SETD2 is one of the key epigenetic regulatory genes involved in histone modifications. Its alterations were potentially oncogenic and commonly found in cancers. Interestingly, SETD2 is one of the most frequent mutated genes found exclusively in phyllodes tumor of the breast (PT). However, little has been done to further characterize SETD2 alterations in PT.

METHODS

In this study, we examined the alterations of SETD2 gene and protein expression in a large cohort of PTs. Their correlations with SETD2 downstream target, H3K36me3 expression, and clinicopathologic features in PT were also assessed.

RESULTS

SETD2 mutation was found in 15.9% of our cases and was mostly predicted to be damaging mutations. Interestingly, SETD2 mutations were associated with lower H3K36me3 expression, particularly those with damaging mutations (p = .041). Neither SETD2 mutations nor H3K36me3 expression was associated with PT grading and other clinicopathological features. By contrast, the SETD2 protein expression cannot reflect its mutation status and showed a different trend of clinicopathological correlations from H3K36me3.

CONCLUSIONS

Our findings may suggest a potential involvement of epigenetic regulation via SETD2 alterations and downstream H3K36me3 on PT development. SETD2 mutations may occur early in the pathogenic process of PTs and its loss per se may not be sufficient for progression to malignancy. Exclusive alterations of SETD2 in PT can be used as markers for the diagnosis of fibroepithelial lesions. The association of H3K36me3 with SETD2 mutations may also indicate the value of evaluation of H3K36me3 expression in the diagnosis of fibroepithelial lesions.

Papillary lesions of the breast: A systematic evaluation of cytologic parameters

BACKGROUND

The cytologic diagnosis of papillary lesions of the breast is challenging because of the diverse morphology, including epithelial hyperplasia, atypia, low-grade malignancy, and neuroendocrine differentiation; also, traditional malignant features such as necrosis and myoepithelial cell loss can be lacking. Thus, the diagnostic criteria for papillary lesions may differ from those for other breast lesions. This study evaluated various cytologic parameters in a large cohort to identify useful diagnostic features.

METHODS

Cytologic preparations of papillary lesions with histologic follow-up were reviewed for features related to cellularity, epithelial cohesiveness, cellular and stromal architecture, cytomorphology, and background. Corresponding histologic slides were also reviewed.

RESULTS

In all, 153 cases were included. Epithelial discohesion, solid and cribriform patterns, atypical nuclear features, and mitoses (P ≤ .001 to P = .017) were associated with malignancy. Cell balls, monolayer sheets, and features of cystic change (P < .001 to P = .016) were associated with benign lesions. Complex (P = .031) and slender (P = .026) papillae and neuroendocrine features (P < .001) were associated with malignancy. Hemorrhage, background, and infiltrating neutrophils (P < .001 to P = .025) were associated with malignancy; fibrotic broad papillary stromal fragments (naked papillary fronds [NPFs]; P = .043) were associated with benignity. The presence of any single parameter, including the absence of myoepithelial cells within epithelial structure, the presence of cytoplasmic granules, an increased amount of cytoplasm, and a nuclear to cytoplasmic (N/C) ratio greater than 0.7, which were identified by principal component analysis, yielded a sensitivity of 95.1% and a specificity of 100.0% in predicting malignancy.

CONCLUSIONS

Methodological assessment of multiple features is recommended. Myoepithelial cells, cytoplasmic granules, the amount of cytoplasm, and the N/C ratio are key features for diagnosis.

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.

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 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 SYN^lo CG^lo and SYN^hi CG^lo 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.

Axillary Nodal Metastasis with Papillary Morphology: An Uncommon Origin

BACKGROUND

Metastases to axillary lymph nodes are commonly and readily confirmed by fine needle aspiration cytology (FNAC). Most likely, these arise from breast primaries. However, the diagnosis can become complicated when unusual cytomorphology is encountered.

CASE

We report a 60-year-old woman presenting with bilateral axillary lymphadenopathies but without breast lesions. History showed increasing CA-125 levels. FNAC yielded carcinoma cells showing prominent papillary pattern, being composed of mild to moderately differentiated malignant cells, with focal abortive glandular formation and squamous metaplasia. IHC stains were done and the tumor cells were PAX-8 positive, but GATA-3 and GCDFP-15 negative. Coupled with the clinical history, a diagnosis of metastatic endometrioid adenocarcinoma was made.

CONCLUSION

Nodal metastases with papillary cytomorphology can rarely arise from nonbreast primaries. The presence of papillary pattern, particularly in the absence of a clinically detectable breast lesion, should raise the possibility of a metastasis. Correlation with patient history, imaging findings and judicious use of IHC studies are crucial for a correct diagnosis.

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.

AJCC 8th edition prognostic staging provides no better discriminatory ability in prognosis than anatomical staging in triple negative breast cancer

BACKGROUND

We retrospectively compared the prognostic value between the AJCC 8th edition anatomic (AS) and prognostic staging (PS) system for triple negative breast cancer (TNBC) in a cohort from two involved institutions and a large population database.

METHODS

Clinicopathological data of TNBCs were identified in two involved institutions (SYSUCC-PWH cohort). Data from SEER database during 2010-2015 was also accessed. We restaged all cases into AS and PS group according to the AJCC 8th staging system.

RESULTS

A total of 611 and 31,941 TNBCs were identified in two cohorts, with a median follow-up of 53.5 and 27 months respectively. PS upstaged 46.1% of patients in SYSUCC-PWH cohort, and 62.4% in SEER cohort. No significant difference was observed in C index between AS and PS models for disease-specific survival (DSS), progression-free survival (PFS) or overall survival (OS) in either cohort. χ2 statistic and Hazard Ratio for PFS, DSS and OS showed better discrimination between IA and IB, IIB and IIIA, IIIA and IIIB in AS model than PS model. Besides, patients with IIIC unchanged stage showed worse PFS compared to those with AS IIIA or IIIB upstaged to PS IIIC in both cohorts(p = 0.049, p < 0.001).

CONCLUSIONS

Our findings demonstrated that prognostic staging system did not provide better discriminatory ability in predicting TNBCs prognosis than anatomic staging system.