Stimulator of interferon genes protein (STING) activates the immune response in inflammatory cells. STING expression in cancer cells is less well characterized, but STING agonists are currently being evaluated as anticancer drugs. A tissue microarray containing 18,001 samples from 139 different tumor types was analyzed for STING by immunohistochemistry. STING-positive tumor cells were found in 130 (93.5%) of 139 tumor entities. The highest STING positivity rates occurred in squamous cell carcinomas (up to 96%); malignant mesothelioma (88.5%–95.7%); adenocarcinoma of the pancreas (94.9%), lung (90.3%), cervix (90.0%), colorectum (75.2%), and gallbladder (68.8%); and serous high-grade ovarian cancer (86.0%). High STING expression was linked to adverse phenotypes in breast cancer, clear cell renal cell carcinoma, colorectal adenocarcinoma, hepatocellular carcinoma, and papillary carcinoma of the thyroid (p < 0.05). In pTa urothelial carcinomas, STING expression was associated with low-grade carcinoma (p = 0.0002). Across all tumors, STING expression paralleled PD-L1 positivity of tumor and inflammatory cells (p < 0.0001 each) but was unrelated to the density of CD8+ lymphocytes. STING expression is variable across tumor types and may be related to aggressive tumor phenotype and PD-L1 positivity. The lack of relationship with tumor-infiltrating CD8+ lymphocytes argues against a significant IFN production by STING positive tumor cells.

Background/Objectives: Trefoil factor 1 (TFF1) plays a role in the mucus barrier. Methods: To evaluate the prevalence of TFF1 expression in cancer, a tissue microarray containing 18,878 samples from 149 tumor types and 608 samples of 76 normal tissue types was analyzed through immunohistochemistry (IHC). Results: TFF1 staining was detectable in 65 of 149 tumor categories. The highest rates of TFF1 positivity were found in mucinous ovarian carcinomas (76.2%), colorectal adenomas and adenocarcinomas (47.1–75%), breast neoplasms (up to 72.9%), bilio-pancreatic adenocarcinomas (42.1–62.5%), gastro-esophageal adenocarcinomas (40.4–50.0%), neuroendocrine neoplasms (up to 45.5%), cervical adenocarcinomas (39.1%), and urothelial neoplasms (up to 24.3%). High TFF1 expression was related to a low grade of malignancy in non-invasive urothelial carcinomas of the bladder (p = 0.0225), low grade of malignancy (p = 0.0003), estrogen and progesterone receptor expression (p < 0.0001), non-triple negativity (p = 0.0005) in invasive breast cancer of no special type, and right-sided tumor location (p = 0.0021) in colorectal adenocarcinomas. Conclusions: TFF1 IHC has only limited utility for the discrimination of different tumor entities given its expression in many tumor entities. The link between TFF1 expression and parameters of malignancy argues for a relevant biological role of TFF1 in cancer. TFF1 may represent a suitable therapeutic target due to its expression in only a few normal cell types.

Occludin is a key component of tight junctions. Reduced occludin expression has been linked to cancer progression in individual tumor types, but a comprehensive and standardized analysis across human tumor types is lacking. To study the prevalence and clinical relevance of occludin expression in cancer, a tissue microarray containing 16,870 samples from 148 different tumor types and 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry. Occludin immunostaining was observed in 10,746 (76.6%) of 14,017 analyzable tumors, including 18.9% with weak, 16.2% with moderate, and 41.6% with strong staining intensity. Occludin positivity was found in 134 of 148 tumor categories and was most frequent in adenocarcinomas (37.5-100%) and neuroendocrine neoplasms (67.9-100%), less common in squamous cell carcinomas (23.8-93%) and in malignant mesotheliomas (up to 48.1%), and rare in Non-Hodgkin’s lymphomas (1-2%) and most mesenchymal tumors. Reduced occludin staining was linked to adverse tumor features in several tumor types, including colorectal adenocarcinoma (advanced pT stage, p < 0.0001; L1 status, p = 0.0384; absence of microsatellite instability, p < 0.0001), pancreatic adenocarcinoma (advanced pT stage, p = 0.005), clear cell renal cell carcinoma (high ISUP grade, p < 0.0001; advanced pT stage, p < 0.0001; high UICC stage, p < 0.0001; distant metastasis, p = 0.0422; shortened overall or recurrence-free survival, p ≤ 0.0116), papillary renal cell carcinoma (high pT stage, p < 0.0001; high UICC stage, p = 0.0228; distant metastasis, p = 0.0338; shortened recurrence-free survival, p = 0.006), and serous high-grade ovarian cancer (advanced pT stage, p = 0.0133). Occludin staining was unrelated to parameters of tumor aggressiveness in breast, gastric, endometrial, and thyroidal cancer. Our data demonstrate significant levels of occludin expression in many different tumor entities and identify reduced occludin expression as a potentially useful prognostic feature in several tumor entities.

Backround: Anterior gradient 2 (AGR2) is a resident endoplasmic reticulum (ER) protein with a vital role in embryonal development, mucus maturation, tissue regeneration, and wound healing. Methods: To determine the prevalence and clinical significance of AGR2 expression in cancer, a tissue microarray containing 14,966 tumors from 134 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry (IHC). Results: AGR2 positivity was found in 103 of 134 tumor categories, and 83 tumor categories contained at least one strongly positive case. AGR2 expression was most frequently seen in tumors of the female genital tract, particularly adenocarcinomas (up to 100%), various breast cancer subtypes (57.1%–100%), urothelial carcinoma (74.6%–100%), adenocarcinomas of the upper and lower gastrointestinal tract (93.6%–99.6%), and pancreaticobiliary cancers (65.2%–98.2%). AGR2 positivity was slightly less common in squamous cell carcinomas (46.4%–77.3%) and mainly absent in mesenchymal and lymphoid tumors. While AGR2 expression was only weak or absent in the normal thyroid, it was moderate to strong in 46.0% of adenomas, 52.8% of follicular carcinomas, and 81.8% of papillary carcinomas of the thyroid. High AGR2 expression was strongly linked to poor ISUP ( p < 0.0001), Fuhrman ( p < 0.0001), and Thoenes ( p < 0.0001) grades as well as advanced pT stage ( p = 0.0035) in clear cell renal cell carcinoma (ccRCC). Low AGR2 expression was associated with high BRE grade in breast cancer ( p = 0.0049), nodal metastasis ( p = 0.0275) and RAS mutation ( p = 0.0136) in colorectal cancer, nodal metastasis ( p = 0.0482) in endometrioid endometrial carcinoma, high grade in noninvasive urothelial carcinoma ( p = 0.0003), and invasive tumor growth in urothelial carcinoma ( p < 0.0001). Conclusions: It is concluded that AGR2 expression occurs in a broad range of different tumor entities and that AGR2 assessment may serve as a diagnostic aid for the distinction of thyroidal neoplasms and as a prognostic marker in various cancer types.

Background: The glucocorticoid receptor (GR) regulates the transcription of thousands of genes. In cancer, both oncogenic and tumor suppressive roles of GR have been proposed. Methods: A tissue microarray containing 18,527 samples from 147 tumor (sub-)types and 608 samples from 76 normal tissue types was analyzed for GR expression by immunohistochemistry. Results: GR positivity was found in 76.4% of 14,349 interpretable cancers, including 18.5% with weak, 19.6% with moderate, and 38.3% with strong positivity. GR positivity appeared in all 147 tumor types, with at least one strongly positive tumor in 136 types. Of out tumor entities, 77 of the 147 showed GR positivity in 100% of the cases analyzed. Only six tumor types had less than 50% GR-positive cases, including adenomas with low-/high-grade dysplasia (32.5%/21.7%), adenocarcinomas (17%) and neuroendocrine carcinomas (45.5%) of the colorectum, endometrial carcinomas (25.6%), and rhabdoid tumors (25%). Reduced GR staining was associated with grade progression in pTa (p < 0.0001) and with nodal metastasis in pT2-4 (p = 0.0051) urothelial bladder carcinoma, advanced pT stage (p = 0.0006) in breast carcinomas of no special type (NST), and high grade (p = 0.0066), advanced pT stage (p < 0.0001), and distant metastasis (p = 0.0081) in clear cell renal cell carcinoma. GR expression was unrelated to clinico-pathological parameters in gastric, pancreatic, and colorectal adenocarcinoma, and in serous high-grade carcinoma of the ovary. Conclusions: GR expression is frequent across all cancer types. Associations between reduced GR expression and unfavorable tumor features in certain cancers suggest that the functional importance of GR-regulated genes in cancer progression depends on the cell of tumor origin.

Loss of S-methyl-5'-thioadenosine phosphorylase (MTAP) expression offers a therapeutic option through synthetic lethality and confers resistance to immune checkpoint inhibitors in various cancers. To assess MTAP prevalence in prostate cancer, a tissue microarray of 17,747 samples was analyzed via immunohistochemistry. Normal prostate glands showed weak to moderate cytoplasmic MTAP staining. In 13,189 interpretable cancers, a complete loss of MTAP staining was seen in 33 (0.3 %) tumors, while MTAP staining was considered 1+ in 14.8 %, 2+ in 42.2 %, and 3+ in 42.7 % of tumors. Fluorescence in situ hybridization analysis of 9 MTAP-negative cancers confirmed homozygous MTAP deletion in all of these tumors. MTAP staining was significantly stronger in cancers harboring the TMPRSS2:ERG fusion than in ERG fusion negative tumors (p < 0.0001). A comparison with clinico-pathological features revealed inverse correlations depending on the ERG fusion status: In ERG-negative cancers, high (3+) MTAP expression correlated with advanced pT stage, high Gleason grade, and early PSA recurrence (p < 0.0001 each). Conversely, in ERG-positive tumors, MTAP expression decreased with advanced pT stage (p < 0.0001), high classical (p = 0.0004) and quantitative Gleason grade (p = 0.0005), and low (1+) MTAP expression was significantly linked to early PSA recurrence (p = 0.0012). Comparison with 11 previously analyzed chromosomal deletions identified ERG-status-dependent positive or negative associations between MTAP expression and deletions of PTEN and 12p13 (p ≤ 0.0274), suggesting functional interactions. Taken together, the results of our study demonstrate that MTAP deficiency is exceedingly rare in prostate cancer, while high MTAP expression is a strong and independent marker for poor prognosis in ERG negative cancers.