KLK7 expression in human tumors: a tissue microarray study on 13,447 tumors.

BACKGROUND: Kallikrein-related peptidase 7 (KLK7) is a chymotrypsin-like serine protease which is essential for the desquamation of corneocytes and thus plays a pivotal role in maintaining skin homeostasis. In cancer, KLK7 overexpression was suggested to represent a route for metastasis through cleavage of cell junction and extracellular matrix proteins of cancer cells. METHODS: To comprehensively determine KLK7 protein expression in normal and neoplastic tissues, a tissue microarray containing 13,447 samples from 147 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry. RESULTS: KLK7 positivity was found in 64 of 147 tumor categories, including 17 tumor categories with at least one strongly positive case. The highest rate of KLK7 positivity was found in squamous cell carcinomas from various sites of origin (positive in 18.1%-63.8%), ovarian and endometrium cancers (4.8%-56.2%), salivary gland tumors (4.8%-13.7%), bilio-pancreatic adenocarcinomas (20.0%-40.4%), and adenocarcinomas of the upper gastrointestinal tract (3.3%-12.5%). KLK7 positivity was linked to nodal metastasis (p = 0.0005), blood vessel infiltration (p = 0.0037), and lymph vessel infiltration (p < 0.0001) in colorectal adenocarcinoma, nodal metastasis in hepatocellular carcinoma (p = 0.0382), advanced pathological tumor stage in papillary thyroid cancer (p = 0.0132), and low grade of malignancy in a cohort of 719 squamous cell carcinomas from 11 different sites of origin (p < 0.0001). CONCLUSIONS: These data provide a comprehensive overview on KLK7 expression in normal and neoplastic human tissues. The prognostic relevance of KLK7 expression and the possible role of KLK7 as a drug target need to be further investigated.

An unusual clinical presentation of a plunging ranula-The plunging ranula with extension to the vallecula.

Key Clinical Message: A plunging ranula may present initially as an extensive vallecular cyst and correct diagnosis may be reached with the use of ultrasound, fluid aspiration for amylase detection, and MRI imaging. Abstract: The ranula is a pseudocyst of the sublingual salivary gland and can be divided into two known subtypes. The simple ranula and plunging ranula. While the simple type can be found in the floor of the mouth, the plunging ranula usually pervades the mylohoid muscle and presents as a cervical swelling. The presented case should outline the difficulties in diagnostic and treatment of an uncommon expression of a mucocele above the mylohoid muscle without presenting either a cervical or an intraoral swelling, only extending towards the vallecula. We present a previously unreported clinical manifestation of a ranula of an 18-year old male, which extends posteriorly, remaining confined in the supramylohyoid muscle space. The cystic lesion protrudes in the oropharynx, and clinically appears as an extensive vallecular cyst. On magnetic resonance imaging the initial suspected diagnosis of a vallecular cyst was changed to the final diagnosis of a plunging ranula. The marsupialization of the cyst sac was performed. Outpatient follow-up revealed a persisting ostium, indicating a continuous extravasation of the sublingual gland. The present case report describes an unusual clinical presentation of a plunging ranula, remaining above the mylohyoid muscle and protruding into the oropharynx, misdirecting to the first suspected diagnosis of a vallecular cyst. The case highlights the useful contribution of the MRI imaging for differential diagnoses and the need for criteria to indicate further investigations.

Frequency of Androgen Receptor Positivity in Tumors: A Study Evaluating More Than 18,000 Tumors.

Androgen receptor (AR) is a transcription factor expressed in various normal tissues and is a therapeutic target for prostate and possibly other cancers. A TMA containing 18,234 samples from 141 different tumor types/subtypes and 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry. AR positivity was found in 116 tumor types including 66 tumor types (46.8%) with ≥1 strongly positive tumor. Moderate/strong AR positivity was detected in testicular sex cord-stromal tumors (93.3-100%) and neoplasms of the prostate (79.3-98.7%), breast (25.0-75.5%), other gynecological tumors (0.9-100%), kidney (5.0-44.1%), and urinary bladder (5.4-24.2%). Low AR staining was associated with advanced tumor stage (pTa versus pT2-4; p < 0.0001) in urothelial carcinoma; advanced pT (p < 0.0001), high tumor grade (p < 0.0001), nodal metastasis (p < 0.0001), and reduced survival (p = 0.0024) in invasive breast carcinoma; high pT (p < 0.0001) and grade (p < 0.0001) in clear cell renal cell carcinoma (RCC); and high pT (p = 0.0055) as well as high grade (p < 0.05) in papillary RCC. AR staining was unrelated to histopathological/clinical features in 157 endometrial carcinomas and in 221 ovarian carcinomas. Our data suggest a limited role of AR immunohistochemistry for tumor distinction and a prognostic role in breast and clear cell RCC and highlight tumor entities that might benefit from AR-targeted therapy.

GAD2 Is a Highly Specific Marker for Neuroendocrine Neoplasms of the Pancreas.

Glutamate decarboxylase 2 (GAD2) is the most important inhibitory neurotransmitter and plays a role in insulin-producing ß cells of pancreatic islets. The limitation of GAD2 expression to a few normal cell types makes GAD2 a potential immunohistochemical diagnostic marker. To evaluate the diagnostic utility of GAD2 immunohistochemistry, a tissue microarray containing 19,202 samples from 152 different tumor entities and 608 samples of 76 different normal tissue types was analyzed. In normal tissues, GAD2 staining was restricted to brain and pancreatic islet cells. GAD2 staining was seen in 20 (13.2%) of 152 tumor categories, including 5 (3.3%) tumor categories containing at least 1 strongly positive case. GAD2 immunostaining was most commonly seen in neuroendocrine carcinomas (58.3%) and neuroendocrine tumors (63.2%) of the pancreas, followed by granular cell tumors (37.0%) and neuroendocrine tumors of the lung (11.1%). GAD2 was only occasionally (<10% of cases) seen in 16 other tumor entities including paraganglioma, medullary thyroid carcinoma, and small cell neuroendocrine carcinoma of the urinary bladder. Data on GAD2 and progesterone receptor (PR) expression (from a previous study) were available for 95 pancreatic and 380 extrapancreatic neuroendocrine neoplasms. For determining a pancreatic origin of a neuroendocrine neoplasm, the sensitivity of GAD2 was 64.2% and specificity 96.3%, while the sensitivity of PR was 56.8% and specificity 92.6%. The combination of PR and GAD2 increased both sensitivity and specificity. GAD2 immunohistochemistry is a highly useful diagnostic tool for the identification of pancreatic origin in case of neuroendocrine neoplasms with unknown site of origin.

Cadherin-17 (CDH17) expression in human cancer: A tissue microarray study on 18,131 tumors.

Cadherin-17 (CDH17) is a membranous cell adhesion protein predominantly expressed in intestinal epithelial cells. CDH17 is therefore considered a possible diagnostic and therapeutic target. This study was to comprehensively determine the expression of CDH17 in cancer and to further assess the diagnostic utility of CDH17 immunohistochemistry (IHC). A tissue microarray containing 14,948 interpretable samples from 150 different tumor types and subtypes as well as 76 different normal tissue types was analyzed by IHC. In normal tissues, a membranous CDH17 staining was predominantly seen in the epithelium of the intestine and pancreatic excretory ducts. In tumors, 53 of 150 analyzed categories showed CDH17 positivity including 26 categories with at least one strongly positive case. CDH17 positivity was most common in epithelial and neuroendocrine colorectal neoplasms (50.0%-100%), other gastrointestinal adenocarcinomas (42.7%-61.6%), mucinous ovarian cancer (61.1%), pancreatic acinar cell carcinoma (28.6%), cervical adenocarcinoma (52.6%), bilio-pancreatic adenocarcinomas (40.5-69.8%), and other neuroendocrine neoplasms (5.6%-100%). OnIy 9.9% of 182 pulmonary adenocarcinomas were CDH17 positive. In colorectal adenocarcinomas, reduced CDH17 staining was linked to high pT (p = 0.0147), nodal metastasis (p = 0.0041), V1 (p = 0.0025), L1 (p = 0.0054), location in the right colon (p = 0.0033), and microsatellite instability (p < 0.0001). The CDH17 expression level was unrelated to tumor phenotype in gastric and pancreatic cancer. In summary, our comprehensive overview on CDH17 expression in human tumors identified various tumor entities that might often benefit from anti-CDH17 therapies and suggest utility of CDH17 IHC for the distinction of metastatic gastrointestinal or bilio-pancreatic adenocarcinomas (often positive) from primary pulmonary adenocarcinomas (mostly negative).

Staining pattern of specific and cross-reacting Melan-A antibodies: A comparative study on 15,840 samples from 133 human tumor types.

The Melan-A (melanocyte antigen) protein, also termed 'melanoma antigen recognized by T cells 1' (MART-1) is a protein with unknown function whose expression is specific for the melanocyte lineage. Antibodies against Melan-A are thus used for identifying melanocytic tumors, but some Melan-A antibodies show an additional - diagnostically useful - cross-reactivity against an unspecified protein involved in corticosteroid hormone synthesis. To comprehensively compare the staining patterns of a specific and a cross-reactive Melan-A antibody in normal and neoplastic tissues, tissue microarrays containing 15,840 samples from 133 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types were analyzed by immunohistochemistry. For the Melan-A-specific antibody 'Melan-A specific' (MSVA-900M), Melan-A positivity was seen in 96.0% of 25 benign nevi, 93.0% of 40 primary and 86.7% of 75 metastatic melanomas, 82.4% of 85 renal angiomyolipomas as well as 96.4% of 84 neurofibromas, 2.2% of 46 granular cell tumors, 1.0% of 104 schwannomas, and 1.1% of 87 leiomyosarcomas. The cross-reactive antibody 'Melan-A+' (MSVA-901M+) stained 98.1% of the tumors stained by 'Melan-A specific'. In addition, high positivity rates were seen in sex-cord-stroma tumors of the ovary (35.3%-100%) and the testis (86.7%) as well as for adrenocortical neoplasms (76.3%-83.0%). Only nine further tumor groups showed Melan-A+ staining, including five different categories of urothelial carcinomas. Our data provide a comprehensive overview on the staining patterns of specific and cross-reactive Melan-A antibodies. The data demonstrate that both antibodies are highly useful for their specific purpose. It is important for pathologists to distinguish these two Melan-A antibody subtypes for their daily work.

Prostein expression in human tumors: a tissue microarray study on 19,202 tumors from 152 different Tumor entities.

BACKGROUND: Prostein (P501S), also termed solute carrier family 45 member 3 (SLC45A3) is an androgen regulated protein which is preferentially expressed in prostate epithelial cells. Because of its frequent expression in prostate cancer, prostein was suggested a diagnostic prostate cancer marker. METHODS: In order to comprehensively assess the diagnostic utility of prostein immunohistochemistry, a tissue microarray containing 19,202 samples from 152 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry. RESULTS: Prostein immunostaining was typically cytoplasmic, granular and perinuclear. Prostein positivity was seen in 96.7% of 419 prostate cancers including 78.3% with strong staining. In 16,709 extra-prostatic tumors, prostein positivity was observed in 7.2% of all cases but only 0.3% had a strong staining. Overall, 50 different extra-prostatic tumor categories were prostein positive, 12 of which included at least one strongly positive case. Extra-prostatic tumors with highest rates of prostein positivity included different subtypes of salivary gland tumors (7.6-44.4%), neuroendocrine neoplasms (15.8-44.4%), adenocarcinomas of the gastrointestinal tract (7.3-14.8%), biliopancreatic adenocarcinomas (3.6-38.7%), hepatocellular carcinomas (8.1%), and adenocarcinomas of other organs (up to 21%). CONCLUSIONS: Our data provide a comprehensive overview on prostein expression in human cancers. Prostein is a highly sensitive prostate cancer marker occurring in > 96% of prostate cancers. Because prostein can also be expressed in various other tumor entities, classifying of a tumor mass as a prostate cancer should not be based on prostein positivity alone.