Comprehensive Gene Expression Analyses of Immunohistochemically Defined Subgroups of Muscle-Invasive Urinary Bladder Urothelial Carcinoma.

A number of urinary bladder urothelial carcinoma (UB UC) mRNA-based classification systems have been reported. It also has been observed that treatment response and prognosis are different for each molecular subtype. In this study, cytokeratin (CK)5/6 and CK20 immunohistochemistry (IHC) were performed, and IHC-based subgroup classification was applied. UB UC was classified into CK5/6 single-positive (SP), CK20 SP, double-positive (DP) and double-negative (DN) subgroups, and transcriptional analysis was performed. The results of gene ontology (GO) terms and functional analysis using differentially expressed genes indicate that, CK5/6 SP and DP subgroups were enriched in cell migration, immune activation, interleukin 6-Janus kinase-signal transducer and activator of transcription 3 (IL6-JAK-STAT3) signaling pathway and tumor necrosis factor-α signaling via the nuclear factor-κB (NF-κB) signaling pathway signature gene. In addition, compared with the other subgroups, the DN subgroup showed inhibited cell movement, cell migration, and cell activation. Furthermore, in survival analysis, the CK5/6 SP subgroup was significantly associated with poor progression-free survival (p = 0.008). The results of our study indicate that the CK5/6 positive subgroup exhibited high gene expression signature related to aggressive behavior and exhibited worse clinical outcome.

Immunohistochemistry of cytokeratin (CK) 5/6, CD44 and CK20 as prognostic biomarkers of non-muscle-invasive papillary upper tract urothelial carcinoma.

AIMS: Immunohistochemical (IHC) staining for cytokeratin (CK) 5/6, CD44 and CK20 has been significantly associated with the prognosis of urinary bladder urothelial carcinoma, and probably reflects its molecular characteristics. We aimed to investigate the IHC-based subgroups and their prognostic effects on non-muscle-invasive papillary upper tract urothelial carcinoma (UTUC). METHODS AND RESULTS: IHC staining for CK5/6, CK20 and CD44 was analysed in 211 patients with non-muscle-invasive papillary UTUC. Staining was classified as showing a negative, positive or normal pattern. We found that CK5/6-negative, CD44-negative and CK20-positive tumours were distinctly high-risk subgroups that were associated with high grade (CK5/6-negative, P < 0.001; CD44-negative, P < 0.001; CK20-positive, P = 0.017) and frequent intravesical recurrence (CK5/6-negative, P = 0.002). Using survival analysis with Kaplan-Meier and log-rank tests, we found that these IHC subgroups were correlated with poor progression-free (CK5/6-negative, P = 0.001; CD44-negative, P = 0.009; CK20-positive, P = 0.031) and cancer-specific (CK5/6-negative, P = 0.009) survival. Furthermore, CK5/6 negativity was an independent prognostic factor for shorter progression-free (P = 0.009) and cancer-specific (P = 0.045) survival. CK5/6 improved Harrell's C-indices for progression-free (0.68-0.77, P = 0.029) and cancer-specific (0.59-0.77, P < 0.001) survival. When markers were combined, luminal-like subtypes showed poor prognoses. CONCLUSIONS: We demonstrated that IHC staining for CK5/6, CD44 and CK20 was significantly associated with the clinicopathological characteristics and prognoses of patients with non-muscle-invasive papillary UTUC. The IHC subgroups may be correlated with the molecular characteristics of non-muscle-invasive papillary UTUC.

The origin of p40-negative and CDX2-positive primary squamous cell carcinoma of the stomach: case report.

BACKGROUND: Primary gastric squamous cell carcinoma (SCC) is a very rare disease. The origin of this tumor remains unclear, although there are some hypotheses. A 60-year-old man consulted a previous physician complaining of upper abdominal pain. Esophagogastroduodenoscopy revealed type 2 gastric cancer, and the patient was referred to our hospital. After close examination, the patient was diagnosed as cStage IIA gastric adenocarcinoma, and distal gastrectomy was performed. Histochemical studies showed typical findings of SCC, and the tumor was surrounded by intestinal metaplasia. Immunohistochemical examination was positive for cytokeratin (CK) 5/6 and caudal-type homeobox protein 2 (CDX2) and negative for p63/p40. CONCLUSION: The results of immunostaining for CK5/6 supported that this tumor was SCC, but the question why p63/p40 were negative and CDX2 was positive still remained. Concerning about the origin of p63/p40 and CDX2, it was suggested that the tumor cells were not derived from ectopic squamous epithelium but from intestinal metaplasia. And tumor cells looked like homogeneous and squamous metaplasia was not observed. These findings supported the idea that these tumor cells arose from stem cells in the intestinal metaplasia of the stomach.

Prognostic impact of EGFR and cytokeratin 5/6 immunohistochemical expression in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) has an aggressive behavior and limited therapeutic options due to lack of targeted therapy. We aimed in this study to assess the immunohistochemical expression of EGFR and cytokeratin 5/6 and their ability to predict survival and response to neoadjuvant chemotherapy (NAC) among triple-negative breast cancer patients. Thirty-five cases with TNBC were studied by immunohistochemistry for EGFR and CK5/6 expression. Data on overall survival (OS), disease-free survival (DFS) and response to NAC were collected. The resulted data were statistically analyzed. Invasive carcinoma of no special type (NST) was the predominant histopathological type (80%). The commonest histological grade was grade II-III (88.6%). About 57.1% of TNBC cases were CK5/6-positive, and 71.4% were EGFR-positive. EGFR expression showed a significant association with tumor grade and axillary lymph node metastasis (p=0.006, 0.016 respectively). EGFR expression was related to unfavorable response to NAC (p=0.036), poor OS (p=0.002) and poor DFS (p=0.003). CK5/6 expression showed a significant association with tumor grade, unfavorable response to NAC, poor OS & DFS (p=0.007, 0.048, <0.001, 0.043 respectively). Immunohistochemical expression of EGFR and/or CK5/6 showed a high significant association with an unfavorable response to NAC, poor DFS &OS (p=0.010, 0.012, 0.030 respectively). CONCLUSIONS: EGFR and CK5/6 are adverse prognostic markers in TNBC. EGFR and CK5/6 expression could serve as biomarkers for identifying TNBC patients with poor survival that are unlikely to benefit from neoadjuvant chemotherapy. So, targeted therapy against EGFR may be a hopeful therapy for TNBC with NAC resistance.

Elucidating encounters of atypical ductal hyperplasia arising in gynaecomastia.

AIMS: Atypical ductal hyperplasia (ADH) rarely arises in gynaecomastia. We set out to understand more clearly the clinical, histological and immunohistochemical features of ADH in this setting. METHODS AND RESULTS: Twenty-five cases of ADH arising in gynaecomastia, nine cases of ductal carcinoma in situ (DCIS) and 36 cases of gynaecomastia with usual ductal hyperplasia (UDH) were studied. Reviews of clinical, morphological and immunohistochemical findings were performed. The extent of cytokeratin 5/6 (CK5/6) luminal epithelial cell staining was assessed (0% = 0, < 10% = 1, 10-50% = 2 and > 50% = 3). Oestrogen receptor (ER) was evaluated using the H-scoring system. The average age of ADH patients was 35 years (range 14-78). ADH was bilateral in 20% and less frequent in active gynaecomastia (24%). ADH often showed a cribriform pattern (72%), with less nuclear variation/size and similar frequency of mitoses than UDH cells. CK5/6 luminal epithelial staining was decreased in ADH (68%) versus UDH (11%). ADH showed high ER expression compared to UDH (H score > 270 in 88% and 14%, respectively). CONCLUSIONS: ADH in gynaecomastia can be distinguished from UDH by morphological and immunohistochemical features. We also identified a subset of young patients (< 25 years) with extensive bilateral ADH. More studies are needed to characterize this patient subset more clearly.

Increase of KLK7, cytokeratin 5/6, and elafin expression in head and neck squamous cell carcinoma compared with lung squamous cell carcinoma.

Squamous cell carcinoma is the most common primary tumor in the head and neck epithelium and is the second most common primary tumor type in the lung. Although morphologically indistinguishable from each other with hematoxylin and eosin stain on histology, the tumors have different protein expression profiles. Using 24 formalin-fixed paraffin embedded squamous cell carcinomas of the lung and 24 squamous cell carcinomas in the head and neck, protein expression for cytokeratin 5/6, kallikrein 7, and elafin was evaluated by immunohistochemistry. All three proteins were found to evidence higher expression in head and neck squamous cell carcinoma as compared with that of squamous cell carcinoma of the lung. The differences in expression may help clinical differentiation between primary tumors of the lung from metastatic tumors to the lung from the oral/laryngeal cavities.

Cytokeratin 7: a re-evaluation of the 'tried and true' in triple-negative breast cancers.

AIMS: Triple-negative breast cancers (TNBCs) are often poorly differentiated tumours that can present clinically as metastases of an unknown primary. Immunohistochemical panels are frequently used to determine the likelihood of a breast primary, but in this tumour subset cytokeratin (CK)7 may be the only positive finding. In this study we aimed to evaluate a commonly employed immunohistochemical panel using a large group of TNBCs (both basal-like and unclassified), and to analyse the CK7 staining patterns. METHODS AND RESULTS: Tissue microarrays containing 138 TNBCs were stained with antibodies against CK7, CK20, gross cystic disease fluid protein 15 (GCDFP-15), and mammaglobin. CK5/6 staining was used to identify basal-like tumours. CK7 staining was notably heterogeneous, with 14.5% of all cases demonstrating ≤20% tumour cell staining. A greater proportion of basal-like TNBCs than of unclassified TNBCs showed focal staining. GCDFP-15 and mammaglobin were not expressed in the majority of TNBCs, and were less frequently positive in basal-like than in unclassified TNBCs. CONCLUSION: TNBCs are commonly negative for most immunomarkers indicative of breast origin, with the exception of CK7. As about one in five TNBCs showed only focal CK7 positivity, use of this marker must be interpreted with caution, especially in small samples, so that the possibility of a breast primary is not overlooked.

Immunohistochemistry scoring of breast tumor tissue microarrays: A comparison study across three software applications.

Digital pathology can efficiently assess immunohistochemistry (IHC) data on tissue microarrays (TMAs). Yet, it remains important to evaluate the comparability of the data acquired by different software applications and validate it against pathologist manual interpretation. In this study, we compared the IHC quantification of 5 clinical breast cancer biomarkers-estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), epidermal growth factor receptor (EGFR), and cytokeratin 5/6 (CK5/6)-across 3 software applications (Definiens Tissue Studio, inForm, and QuPath) and benchmarked the results to pathologist manual scores. IHC expression for each marker was evaluated across 4 TMAs consisting of 935 breast tumor tissue cores from 367 women within the Nurses' Health Studies; each women contributing three 0.6-mm cores. The correlation and agreement between manual and software-derived results were primarily assessed using Spearman's ρ, percentage agreement, and area under the curve (AUC). At the TMA core-level, the correlations between manual and software-derived scores were the highest for HER2 (ρ ranging from 0.75 to 0.79), followed by ER (0.69-0.71), PR (0.67-0.72), CK5/6 (0.43-0.47), and EGFR (0.38-0.45). At the case-level, there were good correlations between manual and software-derived scores for all 5 markers (ρ ranging from 0.43 to 0.82), where QuPath had the highest correlations. Software-derived scores were highly comparable to each other (ρ ranging from 0.80 to 0.99). The average percentage agreements between manual and software-derived scores were excellent for ER (90.8%-94.5%) and PR (78.2%-85.2%), moderate for HER2 (65.4%-77.0%), highly variable for EGFR (48.2%-82.8%), and poor for CK5/6 (22.4%-45.0%). All AUCs across markers and software applications were ≥0.83. The 3 software applications were highly comparable to each other and to manual scores in quantifying these 5 markers. QuPath consistently produced the best performance, indicating this open-source software is an excellent alternative for future use.

fHER2, PR, ER, Ki-67 and Cytokeratin 5/6 Expression in Benign Feline Mammary Lesions.

Biomarkers are essential in the characterization of neoplastic lesions and aid not only in the classification of the nature of the lesions, but also in the understanding of their ontogeny, development and prognosis. In cats, while mammary carcinomas are increasingly being characterized, information on their benign lesions is still scarce. Indeed, a better characterization of benign lesions could have an important role in unravelling mammary oncogenesis, similar to that in human breast cancer. Thus, in this study, the expression of five markers was analyzed in 47 benign mammary lesions (hyperplasia, dysplasia and benign tumors) collected from 27 queens. Dysplastic and hyperplastic lesions were the most common (41/47, 81.7%). Most of the lesions were classified as ER positive (43/47, 91.5%), PR negative (30/47, 63.8%), fHER2 negative (29/47, 64.4%), CK 5/6 negative (36/47, 76.6%) and with a low Ki-67 index (37/47, 78.7%). Statistical analysis revealed a correlation between younger ages and ER positivity (p = 0.013) and between larger lesions and negative PR status (p = 0.038). These results reinforce the importance of evaluating the expression of the ER status, prevalent in benign lesions, as a putative precursor in cancer progression.

CDK14 expression is elevated in patients with non-small cell lung cancer and correlated with poor prognosis.

OBJECTIVE: To investigate the clinical significance of cyclin-dependent kinase 14 (CDK14) expression in patients with non-small cell lung cancer (NSCLC). METHODS: The present prospective observational study included 193 patients diagnosed with NSCLC between January 2010 and December 2014. NSCLC tumor tissues and paired paracancerous normal tissues were obtained from all patients. CDK14, thyroid transcription factor 1 (TTF-1), cytokeratin 5/6 (CK5/6), and Ki67 expression was measured via immunohistochemistry (IHC). RESULTS: CDK14 staining was strong (>3) in 129 patients (66.49%) and weak (≤3) in 64 patients (33.16%). The mean IHC scores were markedly higher in tumor tissues than in paracancerous tissues. Pearson's analysis demonstrated that the IHC scores of CDK14 expression were positively correlated with TTF-1, CK5/6, and Ki67 scores. Kaplan-Meier analysis illustrated that 5-year overall survival was markedly longer in patients with weak CDK14 staining. TNM stage, pleural invasion, lymph node metastasis, CDK14 expression, and Ki67 expression were risk factors for 5-year overall survival in patients with NSCLC. CONCLUSION: CDK14 overexpression portended poor outcomes in patients with NSCLC, and CDK14 expression was correlated with TTF-1, CK5/5, and Ki67 expression.

Genetic Variation and Immunohistochemical Localization of the Glucocorticoid Receptor in Breast Cancer Cases from the Breast Cancer Care in Chicago Cohort.

BACKGROUND: Glucocorticoid, one of the primary mediators of stress, acts via its receptor, the glucocorticoid receptor (GCR/NR3C1), to regulate a myriad of physiological processes. We measured the genetic variation and protein expression of GCR, and the genes that regulate GCR function or response and examined whether these alterations were associated with breast cancer clinicopathological characteristics. METHOD: We used samples from a multiracial cohort of breast cancer patients to assess the association between breast cancer characteristics and the genetic variants of single nucleotide polymorphisms (SNPs) in GCR/NR3C1, FKBP5, Sgk1, IL-6, ADIPOQ, LEPR, SOD2, CAT, and BCL2. RESULTS: Several SNPs were associated with breast cancer characteristics, but statistical significance was lost after adjustment for multiple comparisons. GCR was detected in all normal breast tissues and was predominantly located in the nuclei of the myoepithelial cell layer, whereas the luminal layer was negative for GCR. GCR expression was significantly decreased in all breast cancer tissue types, compared to nontumor tissue, but was not associated with breast cancer characteristics. We found that high nuclear GCR expression was associated with basal cell marker cytokeratin 5/6 positivity. CONCLUSION: GCR expression is reduced in breast cancer tissue and correlates with the basal cell marker CK5/6.

PD-L1 Expression in Muscle-Invasive Urinary Bladder Urothelial Carcinoma According to Basal/Squamous-Like Phenotype.

Urothelial carcinoma (UC) is the most common histologic type of urinary bladder cancer, and muscle-invasive UC shows aggressive behaviors. Programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) blockades have been approved as standard treatments for patients with advanced stage UC. A total of 166 muscle-invasive urinary bladder cancer (MIBC) patients, who underwent transurethral resection of the bladder or cystectomy from 2004 to 2010 were included. We evaluated PD-L1 expression by the SP142 and SP263 assays and classified the cases "positive" or "negative" according to the manufacturer's recommendations. We performed immunohistochemistry (IHC) for cytokeratin (CK) 5/6, CK14, GATA3, FOXA1, and CK20 and classified samples as Basal-Squamous-like (BASQ) or non-BASQ subtype. The overall concordance rate for PD-L1 expression is 91.6% (152/166) (kappa = 0.732). The SP142 assay showed 15.1% positivity; the SP263 assay showed 23.5%. The high positivity in the SP142 and SP263 assay was significantly correlated with positive CK5/6, CK14 expression, negative GATA3, FOXA1, and CK20 expression. Classification according to IHC expression resulted in 12.0% (20/166) of samples being classified as BASQ subtype and 88.0% (146/166) of samples being classified as non-BASQ subtype. High positivity in the SP142 and SP263 assay was significantly correlated with the BASQ subtype (p < 0.001, both). Our study is the first to analyze the association of immunohistochemically defined BASQ and non-BASQ subtypes with two PD-L1 assays in MIBC. In conclusion, we revealed that a high PD-L1 positive rate in all PD-L1 assays was significantly associated with the BASQ-subtype, and these results suggest that the BASQ classification may be important to apply the PD-1/PD-L1 blockades in MIBC.

Cryopreserved human umbilical cord versus acellular dermal matrix patches for in utero fetal spina bifida repair in a pregnant rat model.

OBJECTIVE: Despite significant improvement in spinal cord function after in utero spina bifida (SB) repair compared with traditional postnatal repair, over half of the children who undergo this procedure do not benefit completely. This lack of benefit has been attributed to closure methods of the defect, with subsequent spinal cord tethering at the repair site. Hence, a regenerative patch or material with antiinflammatory and anti-scarring properties may alleviate comorbidities with improved outcomes. The authors' primary objective was therefore to compare cryopreserved human umbilical cord (HUC) versus acellular dermal matrix (ADM) patches for regenerative repair of in utero SB lesions in an animal model. METHODS: In vivo studies were conducted in retinoic acid-induced SB defects in fetuses of Sprague-Dawley rats. HUC or ADM patches were sutured over the SB defects at a gestational age of 20 days. Repaired SB defect tissues were harvested after 48-52 hours. Tissue sections were immunofluorescently stained for the presence of neutrophils, macrophages, keratinocytes, meningeal cells, and astrocytes and for any associated apoptosis. In vitro meningeal or keratinocyte cell coculture experiments with the ADM and HUC patches were performed. All experiments were scored quantitatively in a blinded manner. RESULTS: Neutrophil counts and apoptotic cells were lower in the HUC-based repair group (n = 8) than in the ADM patch repair group (n = 7). In the HUC patch repair group, keratinocytes were present on the outer surface of the patch, meningeal cells were present on the inner surface of the patch adjacent to the neural placode, and astrocytes were noted to be absent. In the ADM patch repair group, all 3 cell types were present on both surfaces of the patch. In vitro studies showed that human meningeal cells grew preferentially on the mesenchymal side of the HUC patch, whereas keratinocytes showed tropism for the epithelial side, suggesting an inherent HUC-based cell polarity. In contrast, the ADM patch studies showed no polarity and decreased cellular infiltration. CONCLUSIONS: The HUC patch demonstrated reduced acute inflammation and apoptosis together with superior organization in regenerative cellular growth when compared with the ADM patch, and is therefore likely the better patch material for in utero SB defect repair. These properties may make the HUC biomaterial useful as a "meningeal patch" during spinal cord surgeries, thereby potentially reducing tethering and improving on spinal cord function.

Cytokeratin 5/6 expression in bladder cancer: association with clinicopathologic parameters and prognosis.

OBJECTIVES: Well differentiated keratinized squamous component as a part of urothelial carcinoma can be easily appreciated; however non-keratinizing squamous differentiation closely resembles urothelial differentiation. In addition prognostic significance of CK 5/6 expression in the absence of apparent squamous differentiation is still unclear. Therefore, in the present study we aimed to evaluate the frequency of CK 5/6 expression in 127 cases of urothelial carcinoma and its prognostic significance in loco-regional population. RESULTS: Positive CK5/6 expression was noted in 6.3% (8 cases) and 13.4% (17 cases) revealed focal positive CK 5/6 expression. On the other hand, 80.3% (102 cases) showed negative CK5/6 staining. Significant association of CK5/6 expression was noted with tumor grade and muscularis propria invasion, however no significant association was noted with overall and disease free survival. On the basis of the results of our study we can conclude that CK5/6 is an independent prognostic biomarker in urothelial carcinoma and therefore can be used in the prognostic stratification of the patients with bladder cancer.

Expressions of serum N-terminal osteocalcin and cytokeratin 5/6 in primary lung cancer patients with bone metastasis and their clinical significances / 肿瘤研究与临床

Objective:To explore the expressions of serum N-terminal osteocalcin (N-MID) and cytokeratin (CK) 5/6 in primary lung cancer patients with bone metastasis and their clinical significances.Methods:The clinical data of 96 patients with primary lung cancer admitted to Chengdu Second People's Hospital between February 2019 to February 2022 were retrospectively analyzed. All patients were divided into the bone metastasis group (38 cases) and the non-bone metastasis group (58 cases) according to whether bone metastasis occurred, and 45 healthy people who underwent physical examination during the same period were treated as the healthy control group. The expression levels of serum N-MID and CK5/6 in the bone metastasis group, the non-bone metastasis group and the healthy control group were compared. Logistic regression was used to analyze the factors affecting bone metastasis in patients with primary lung cancer; receiver operating characteristic (ROC) curve analysis was used to analyze the value of the expression levels of serum N-MID and CK5/6 in predicting bone metastasis in patients with primary lung cancer.Results:The composition ratio of patients with pathological stage Ⅲ-Ⅳ, serum bone-derived alkaline phosphatase and N-MID expression levels in the bone metastasis group were higher than those in the non-bone metastasis group (all P < 0.05). The expression level of serum N-MID in the bone metastasis group and non-bone metastasis group was higher than that in the healthy control group [(26.0±5.3) ng/ml, (15.3±3.1) ng/ml vs. (9.9±1.7) ng/ml, F = 224.27, P < 0.001], and there were statistically significant differences in the serum N-MID expression level of the pairwise comparison among the three groups (all P < 0.05). The expression level of serum CK5/6 in the bone metastasis group and the non-bone metastasis group was lower than that in the healthy control group [(3.6±0.7) ng/ml, (7.3±1.4) ng/ml vs. (10.6±2.4) ng/ml, F = 178.11, P < 0.001], and there were statistically significant differences in the serum CK5/6 expression level of the pairwise comparison among the three groups (all P < 0.05). Multivariate analysis showed that CK5/6, N-MID and bone-derived alkaline phosphatase were independent affecting factors for bone metastasis in patients with primary lung cancer ( OR = 4.088, 3.615, 2.892, all P < 0.05). ROC curve analysis showed that the optimal cut-off values of serum N-MID and CK5/6 expression levels for predicting bone metastasis in patients with primary lung cancer were 18.59 ng/ml and 4.71 ng/ml; the corresponding the area under the curve (AUC) was 0.881 and 0.862, respectively; and the specificity and AUC of the combination of serum N-MID and CK5/6 in predicting the bone metastasis in patients with primary lung cancer was 98.28% and 0.937 (95% CI 0.869-0.977), respectively; the AUC predicted by the combination of both was higher than that by serum N-MID or CK5/6 single (all P < 0.001). Conclusions:The expression levels of serum N-MID and CK5/6 in primary lung cancer patients with bone metastasis are abnormally changed. Clinical detection of serum N-MID and CK5/6 expression levels may be used as sensitive indicators for predicting the bone metastasis in patients with primary lung cancer.

Focal positivity of immunohistochemical markers for pulmonary squamous cell carcinoma in primary pulmonary choriocarcinoma: A histopathological study.

Cytokeratin 5/6 (CK5/6), p63, and p40 are commonly used as immunohistochemical markers for squamous cell carcinoma (SqCC) of the lung. To elucidate their positivity in primary pulmonary choriocarcinoma (PPC), the present study examined 4 PPCs, including 1 surgically removed PPC and 3 postmortem PPCs. All PPCs consisted of nested cytotrophoblastic tumor cells and occasional syncytiotrophoblastic tumor cells although 1 surgically removed PPC was markedly affected by pre-operative therapy-associated necrosis and 3 postmortem PPCs coexisted with adenocarcinoma. In 1 surgical case, a pre-operative biopsy specimen of PPC contained a few polygonal tumor cells, which mimicked SqCC and exhibited focal p40+ features. Nuclear p63+ and p40+ features of cytotrophoblast-like polygonal tumor cells were focally observed in 3 PPCs (75%) and 2 PPCs (50%), respectively. CK5/6+ trophoblastic tumor cells were focally identified in 1 PPC. Additionally, in 2 other PPCs, CK5/6+ tumor cells were scattered in choriocarcinomatous areas, but possible intermingling of CK5/6+ adenocarcinoma cells could not be ruled out. The results emphasized that PPCs could mimic SqCC morphologically and immunohistochemically, although PPC was an extremely rare neoplasm. Surgical pathologists should be aware of this diagnostic pitfall when encountering a few squamous marker-positive polygonal tumor cells within hemorrhagic necrotic biopsy specimens from lung tumors.

Androgen receptor expression is a favorable prognostic factor in triple-negative breast cancers.

Androgen receptor (AR) expression is an emerging prognostic marker that has been observed in 25% to 75% of triple-negative breast cancers (TNBCs) that lack estrogen receptor, progesterone receptor and HER2 overexpression. TNBCs are treated with AR-targeted therapies and standardized evaluation of AR expression may help guide patient management. Basal-like TNBCs are a subgroup of TNBCs defined by positive immunoreactivity for CK5/6 or EGFR that carry a worse prognosis. However, it's unclear whether basal-like TNBCs have a different rate of AR positivity or if AR expression is predictive of disease-free survival (DFS) in this patient group. Here, we examined a total of 185 TNBCs for AR and CK5/6 using tissue microarrays (TMAs). Among all samples, 32% were AR positive using a 1% cutoff, and 24% were AR positive using a 10% cutoff. Ninety (49%) TNBCs were CK5/6 positive with lower intensity of AR expression compared to CK5/6-negative cases. There was no significant difference in pathologic stage, tumor size, histologic grade and type, or lymph node stage after stratifying by AR and CK5/6 positivity. AR-positive TNBCs had better overall survival (OS) and DFS compared to AR-negative TNBCs. In addition, increased AR expression carried a dose-dependent effect on DFS. AR expression, nodal status and tumor size were significant predictors of disease-free and overall survival in a multivariable model adjusted for CK5/6 expression, age, histologic grade, and mitotic rate. In conclusion, our data demonstrated that AR positivity is a favorable prognostic factor for triple-negative breast cancers.

Thyroid transcription factor-1 expression in invasive and non-invasive urothelial carcinomas.

BACKGROUND: Thyroid transcription factor-1 (TTF-1) has been considered a sensitive marker for thyroid and lung tumors. Recent data have shown that a wide range of neoplasms may express TTF-1. CASE SERIES: We performed an immunohistochemical study in a case series of 42 urothelial carcinomas (UCs) on tissue microarrays sections, in order to investigate how often UCs express the TTF-1 protein and the diagnostic utility of this marker. In addition, we sought to determine by immunohistochemistry if there is an association between TTF-1 expression and the expression of specific basal-like or luminal markers. Five out of the 42 cases (11.9 %) were positive for TTF-1. Three positive tumors concerned non-invasive papillary UCs. There was no association between TTF-1 expression and tumor grade (χ2, p =0.419), stage (χ2, p =0.550) or cytokeratin 5/6 (χ2, p =0.330), cytokeratin 20 (χ2, p =0.995) and estrogen receptors expression (χ2, p =0.268). CONCLUSIONS: UCs may show TTF-1 expression and pathologists should be aware of this phenomenon in order to avoid misdiagnosis, notably in metastatic disease. HIPPOKRATIA 2017, 21(3): 154-157.

Cytokeratin 5/6 expression, prognosis, and association with estrogen receptor α in high-grade serous ovarian carcinoma.

High-grade serous ovarian carcinoma remains one of the most lethal malignancies in women. For histopathologic differentiation from mesothelioma cytokeratin, 5/6 immunohistochemistry is widely used. Another preferred marker for differential diagnosis to mesothelioma is estrogen receptor α (ER-α). In this study, we determined the rate of cytokeratin 5/6-positive cells in primary high-grade serous carcinoma. A cohort of 215 patients with high-grade serous ovarian carcinoma was evaluated immunohistochemically for the protein expression of cytokeratin 5/6. Most tumors demonstrated at least partly positive for cytokeratin 5/6 (n=148; 68.3%), showing different staining patterns from scattered stained cells to a diffuse staining, at times with a distinctive tumor-stroma border motif. Sixty-seven (31%) were entirely negative. No correlation of cytokeratin immunoreactivity score (IRS) with conventional staging parameters could be demonstrated. From the different IRS values for cytokeratin 5/6, IRS=12 (n=6; 2.9%) seemed to indicate a worse prognosis, albeit not statistically significant. An association with ER-α expression could not be detected but the combination of cytokeratin 5/6 IRS=12 and ER-α negativity resulted in a significant negative prognostic marker (overall survival: P=.003 and progression-free survival: P<.0001). We substantiate cytokeratin 5/6 protein expression as a frequent feature of high-grade serous ovarian carcinoma with various staining patterns, an important fact for the routine differential diagnosis with mesothelioma. Furthermore, cytokeratin 5/6 in combination with ER-α proved to be a negative prognostic marker, wherefore we suggest further investigation of its biological significance and possible manifestation of a basal differentiation.

The unique luminal staining pattern of cytokeratin 5/6 in adenoid cystic carcinoma of the breast may aid in differentiating it from its mimickers.

Adenoid cystic carcinoma (AdCC) of the breast is an uncommon but distinct neoplasm composed of a dual cell population polarized around true glandular (luminal) spaces and pseudolumina. The aim of this study was to clarify whether various immunohistochemical markers (CK7, EMA, CD117, p63, calponin, CD10, S100, CK5/6, CK14, vimentin, and type IV collagen) can distinguish between the two cell types in classical AdCC (n = 14) and in collagenous spherulosis (n = 5). The sensitivity and specificity of these 11 markers to distinguish luminal from abluminal cells were evaluated using a curve created by plotting the true-positive rate (sensitivity) against the false-positive rate (1 - specificity) at threshold settings of 0, 10, 50, and 70 %. The most sensitive and specific markers for luminal cells in AdCC were CK7 and EMA; those for abluminal cells were type IV collagen, p63, and vimentin. CD10 and S100 did not act as abluminal markers in AdCC. CK5/6, one of the basal/myoepithelial markers, was expressed more frequently in luminal than in abluminal cells of AdCC. Thus, CK5/6 immunostaining resulted in a reverse expression pattern, analogous to what we recently documented in clear cells in mammary adenomyoepithelioma. In conclusion, compared with myoepithelial/abluminal cells of normal breast or collagenous spherulosis, the neoplastic abluminal cells of classical AdCC are characterized by enhanced vimentin and attenuated CD10 and S100. Furthermore, the luminal cells of AdCC show a unique aberrant staining pattern for CK5/6 that may aid in the differential diagnosis.