Current and Future Biomarkers in Esophagogastric Adenocarcinoma.

PURPOSE: Biomarker-based therapies have shown improved patient outcomes across various cancer types. The purpose of this review to summarize our knowledge of current and future biomarkers in esophagogastric adenocarcinoma (EGA). METHODS: In this publication, we will review current standard biomarkers in patients with upper GI cancers. We will also discuss novel biomarkers that are under investigations and their associated therapies that are currently in clinical trials. RESULTS: EGAa are a group of heterogeneous diseases, both anatomically and molecularly. There are several established biomarkers (HER2, PD-L1, microsattelite instability or mismatch repair protein expression) that allow for individualized treatments for patients with these cancers. There are also several emerging biomarkers for EGA, some of which have clinically relevant associated therapies. Claudin 18.2 is the furthest along among these. Anti-claudin antibody, zolbetuximab, improved overall survival in biomarker select patients with advanced GEA in two phase 3 studies. Other novel biomarkers, such as FGFR2b and DKN01, are also in the process of validation, and treatments based on the presence of these biomarkers are currently in clinical studies. CONCLUSION: Ongoing efforts to identify novel biomarkers in EGA have led to enhanced subclassification of upper GI cancers. These advances, coupled with the strategic application of targeted therapies and immunotherapy when appropriate, hold promise to further improve patients outcomes.

Stratified Mucin-producing Lesions of the Anus: Insights into an Emerging Histologic Type of HPV-driven Anal Neoplasia.

Primary anal cancers are rare and typically driven by high-risk human papillomavirus (HPV) infection. Though squamous cell carcinoma is most common, a spectrum of HPV-related nonsquamous anogenital neoplasms with similarities to cervical stratified mucin-producing carcinoma has been reported. In this study, we mined our institutional archives to characterize the clinicopathologic features of this emerging entity. Six cases were identified from the files at 2 institutions, including 4 cases of invasive stratified mucin-producing carcinoma and 2 stratified mucin-producing intraepithelial lesions (SMILE). Four patients were women, and the mean age was 70 years. Patients presented with rectal/anal mass or polyp, rectal bleeding or pain, weight loss, or at the time of screening colonoscopy. Tumors displayed histologic features as described in the gynecologic tract. Cases of invasive stratified mucinous carcinoma showed infiltrative tumor nests with variable intracytoplasmic mucin, peripheral palisading, prominent apoptosis, and neutrophilic infiltrate. One invasive stratified mucinous carcinoma associated with high grade glandular dysplasia, whereas 1 SMILE was next to conventional low-grade squamous intraepithelial lesion. All lesions stained with p16 showed block-like p16 expression. HPV in situ hybridization was performed in 5 cases, 4 of which were positive; one was interpreted as equivocal. Follow-up information, available in 4 patients, revealed 1 local recurrence followed by death due to unrelated causes in a patient with invasive stratified mucin-producing carcinoma. We report the first series of HPV-associated primary anal stratified mucin-producing neoplasms analogous to those seen in the gynecologic tract, further broadening the spectrum of HPV-related anal neoplasia.

A Rare Case of Well-Differentiated Neuroendocrine Tumor Arising From a Jejunal Pancreatic Heterotopia.

Pancreatic heterotopia is a well-described entity occurring at multiple abdominal sites, most commonly the stomach and small intestine. They can develop similar disease processes as the pancreas ranging from acute pancreatitis, cyst formation, or neoplasms, most commonly ductal adenocarcinoma. Neuroendocrine tumors (NETs) arising in pancreatic heterotopias are exceedingly rare with only 3 prior published cases. In this article, we describe the first reported case of a NET arising in a jejunal pancreatic heterotopia in a 59-year-old woman presenting with abdominal pain and diarrhea. The submucosal tumor was composed of a well-differentiated NET (World Health Organization grade 1) directly intermixed with a heterotopic pancreas consisting of acinar cells, islet cells, and ducts. This case illustrates that NETs can occur in association with pancreatic heterotopias at any site. Also, the importance for pathologists to recognize that pancreatic heterotopias can give rise to a variety of neoplasms and is not limited to ductal adenocarcinoma.

Well-differentiated rectal neuroendocrine tumors: analysis of histology, including insulinoma-associated protein 1 expression, and biologic behavior, involving a large cohort of 94 cases.

Well-differentiated rectal neuroendocrine tumors (R-NETs) are increasingly being detected by screening colonoscopy, commonly manifesting as polyps. Chromogranin A is frequently negative in R-NETs. Insulinoma-associated protein 1 (INSM1) is a novel transcription factor that has recently shown excellent sensitivity and specificity for neuroendocrine (NE) differentiation in various anatomic sites but has not been systematically evaluated in R-NET. A retrospective histologic review of all available R-NETs was performed and stained for INSM1 immunohistochemistry, as well as for Ki-67 and chromogranin A, if not already available. Clinical and follow-up information was obtained from the medical chart. A total of 94 R-NETs were included in our cohort. Of these, 82 (87%) were <10 mm in greatest dimension, and submucosal involvement was noted in 70 patients (74%). The tumors displayed a variety of histologic patterns, and the majority of the cases had intratumoral fibrosis (61%). Synaptophysin and INSM1 were reactive in 100% cases, whereas chromogranin A was reactive in 45% cases. The mean Ki-67 proliferative index was 1.6% (range: 0.5-5%). The median follow-up of the cohort was 30 months (80 cases, range: 3-226 months). Only three patients were identified with regional lymph node metastasis, all of which showed a tumor size ≥10 mm and had lymphovascular invasion (LVI). R-NETs in our fairly large cohort display an indolent biologic behavior without distant metastasis. Metastatic disease in lymph nodes was associated with tumor size and the presence of LVI, but not with the Ki-67 proliferative index. This is also the first systematic study documenting INSM1 as a highly sensitive NE marker in R-NET.