Bellizzi, Andrew M.

Abstract Incretin‐based therapies, including glucagon‐like peptide‐1 receptor agonists (GLP‐1RA) and dual incretin agonists, are increasingly used for the management of diabetes, obesity, and cardiometabolic disease. Although their systemic benefits are well established, uncertainty remains regarding their safety in patients with neuroendocrine neoplasms (NENs), a biologically heterogeneous group of tumors with diverse molecular profiles. Preclinical studies suggest that GLP‐1 receptor activation may promote tumor growth in select receptor‐expressing models, although receptor expression varies widely across NEN subtypes and is often absent in common tumors such as ileal neuroendocrine tumors. Population‐level and retrospective clinical data have not demonstrated a consistent increase in oncologic risk but are limited by methodological constraints. In this expert consensus statement, the authors synthesize current evidence and provide a practical framework for the use of incretin mimetics in patients with NENs. The authors emphasize individualized risk assessment, shared decision‐making, and multi‐disciplinary collaboration, balancing potential but unquantified oncologic risks against substantial cardiometabolic benefits. Until prospective data are available, careful patient selection, dose optimization, and close clinical and radiologic surveillance remain essential to guide safe and effective use of these agents in this population.

The WHO 2019 classification of digestive tract tumors introduced a high-grade (G3) category for well-differentiated neuroendocrine tumors (NETs). These neoplasms appear to have a better prognosis than poorly differentiated neuroendocrine carcinomas (NECs) and may not respond to platinum-based chemotherapy, which is the treatment of choice for NECs, justifying the creation of this new category. Most existing data on G3 NETs are derived from pancreatic neuroendocrine neoplasms, as the majority of G3 neuroendocrine neoplasms (NENs) arise there. G3 NETs are rare at extrapancreatic sites, and their prognosis and behavior are not well studied. We collected and analyzed a multi-institutional cohort of 24 extrapancreatic primary gastrointestinal G3 NETs based on mitotic rate and/or Ki67 index (5 gastric, 13 small bowel, 6 colorectal/anal). Mean Ki67 index was 29.3% (range: 10.5% to 50.2%). Cases generally showed typical well-differentiated NET morphology. Nodal metastases were present in 17/17 (100%) patients; 13/24 (45%) had distant metastases at initial presentation, and 7 patients developed them on follow-up. With a median of 29 months of follow-up, only 2 patients (8%) were alive without disease. Outcomes of G3 NETs were compared with a separate cohort of 125 extrapancreatic G1/G2 gastrointestinal NETs. G3 tumors presented at a higher pT-category stage ( P <0.001) and overall stage ( P =0.002), and patients with G3 disease were more likely to die than those with G1/G2 disease ( P <0.001). Our data show that, like pancreatic G3 NETs, rare extrapancreatic gastrointestinal G3 NETs exhibit aggressive behavior compared with their G1/G2 counterparts (although small bowel NETs tend to recur irrespective of grade). In most cases, the G3 designation is driven by Ki67 index, though exceptions exist, emphasizing the need for reviewing mitotic count in every case.

Abstract The American Joint Committee on Cancer (AJCC) staging system for all cancer sites, including gastroenteropancreatic neuroendocrine tumors (GEP‐NETs), is meant to be dynamic, requiring periodic updates to optimize AJCC staging definitions. This entails the collaboration of experts charged with evaluating new evidence that supports changes to each staging system. GEP‐NETs are the second most prevalent neoplasm of gastrointestinal origin after colorectal cancer. Since publication of the AJCC eighth edition, the World Health Organization has updated the classification and separates grade 3 GEP‐NETs from poorly differentiated neuroendocrine carcinoma. In addition, because of major advancements in diagnostic and therapeutic technologies for GEP‐NETs, AJCC version 9 advocates against the use of serum chromogranin A for the diagnosis and monitoring of GEP‐NETs. Furthermore, AJCC version 9 recognizes the increasing role of endoscopy and endoscopic resection in the diagnosis and management of NETs, particularly in the stomach, duodenum, and colorectum. Finally, T1NXM0 has been added to stage I in these disease sites as well as in the appendix.

PURPOSE To develop recommendations for systemic therapy for well-differentiated grade 1 (G1) to grade 3 (G3) metastatic gastroenteropancreatic neuroendocrine tumors (GEP-NETs). METHODS ASCO convened an Expert Panel to conduct a systematic review of relevant studies and develop recommendations for clinical practice. RESULTS Eight randomized controlled trials met the inclusion criteria for the systematic review. RECOMMENDATIONS Somatostatin analogs (SSAs) are recommended as first-line systemic therapy for most patients with G1-grade 2 (G2) metastatic well-differentiated GI-NETs. Observation is an option for patients with low-volume or slow-growing disease without symptoms. After progression on SSAs, peptide receptor radionuclide therapy (PRRT) is recommended as systematic therapy for patients with somatostatin receptor (SSTR)–positive tumors. Everolimus is an alternative second-line therapy, particularly in nonfunctioning NETs and patients with SSTR-negative tumors. SSAs are standard first-line therapy for SSTR-positive pancreatic (pan)NETs. Rarely, observation may be appropriate for asymptomatic patients until progression. Second-line systemic options for panNETs include PRRT (for SSTR-positive tumors), cytotoxic chemotherapy, everolimus, or sunitinib. For SSTR-negative tumors, first-line therapy options are chemotherapy, everolimus, or sunitinib. There are insufficient data to recommend particular sequencing of therapies. Patients with G1-G2 high-volume disease, relatively high Ki-67 index, and/or symptoms related to tumor growth may benefit from early cytotoxic chemotherapy. For G3 GEP-NETs, systemic options for G1-G2 may be considered, although cytotoxic chemotherapy is likely the most effective option for patients with tumor-related symptoms, and SSAs are relatively ineffective. Qualifying statements are provided to assist with treatment choice. Multidisciplinary team management is recommended, along with shared decision making with patients, incorporating their values and preferences, potential benefits and harms, and other characteristics and circumstances, such as comorbidities, performance status, geographic location, and access to care. Additional information is available at www.asco.org/gastrointestinal-cancer-guidelines .

AbstractCutaneous T-cell lymphomas (CTCLs) are a spectrum of diseases with varied clinical courses caused by malignant clonal proliferation of skin-tropic T cells. Most patients have an indolent disease course managed with skin-directed therapies. In contrast, others, especially in advanced stages of disease or with specific forms, have aggressive progression and poor median survival. Sézary syndrome (SS), a leukemic variant of CTCL, lacks highly consistent phenotypic and genetic markers that may be leveraged to prevent the delay in diagnosis experienced by most patients with CTCL and could be useful for optimal treatment selection. Using single-cell mRNA and T-cell receptor sequencing of peripheral blood immune cells in SS, we extensively mapped the transcriptomic variations of nearly 50 000 T cells of both malignant and nonmalignant origins. We identified potential diverging SS cell populations, including quiescent and proliferative populations shared across multiple patients. In particular, the expression of AIRE was the most highly upregulated gene in our analysis, and AIRE protein expression could be observed over a variety of CTCLs. Furthermore, within a single patient, we were able to characterize differences in cell populations by comparing malignant T cells over the course of treatment with histone deacetylase inhibition and photopheresis. New cellular clusters after progression of the therapy notably exhibited increased expression of the transcriptional factor FOXP3, a master regulator of regulatory T-cell function, raising the potential implication of an evolving mechanism of immune evasion.

Context.— Comprehensive genomic profiling has demonstrated that approximately 20% of pancreatic carcinomas with acinar differentiation harbor potentially targetable BRAF fusions that activate the MAPK pathway. Objectives.— To validate the above finding by BRAF break-apart fluorescence in situ hybridization (FISH) in a large series of pure acinar cell carcinomas (ACCs), evaluate tumors for the presence of BRAF V600E mutations, and compare clinicopathologic features of tumors with BRAF rearrangements with those without. Design.— Thirty cases of pure ACC and 6 cases of mixed acinar-neuroendocrine carcinoma (ACC-NEC) were retrieved. A break-apart FISH probe was used to detect BRAF rearrangements. Immunohistochemistry for BRAF V600E was performed. Results.— BRAF rearrangements by FISH were found in 6 of 36 cases (17%), 5 of which were pure ACC and 1 was a mixed ACC-NEC. Follow-up was available in 29 of 36 cases (81%). The median survival was 22 months for BRAF-rearranged cases and 16 months for BRAF-intact cases; the 2-year overall survival was 50% for BRAF-rearranged cases and 35% for BRAF-intact cases. No significant clinicopathologic differences were identified in cases with BRAF rearrangement compared with those without BRAF rearrangement. BRAF V600E mutation was identified in 2 of 34 cases (6%), both of which were pure ACC and were BRAF-intact by FISH. Conclusions.— This study supports the finding that BRAF rearrangements are present in approximately 20% of cases and identified BRAF V600E mutations in approximately 5% of cases. These cases may benefit from targeted therapy.

AimsThe diagnosis of focal nodular hyperplasia (FNH) and the interpretation of glutamine synthetase (GS) staining can be challenging on biopsies. We aimed to evaluate the reproducibility of needle biopsy diagnosis of FNH, the effect of GS immunohistochemistry on FNH diagnosis, and which histological features are most useful for the diagnosis of FNH.Methods and resultsThe study included virtual needle biopsies generated from 75 resection specimens (30 FNHs, 15 hepatocellular adenomas, 15 hepatocellular carcinomas, and 15 non‐lesional liver specimens). Pathologists were reasonably accurate (83.1%) in the diagnosis of FNH with haematoxylin and eosin alone. Ductular reaction and nodularity had the highest sensitivity for a diagnosis of FNH (88.1% and 82.2%, respectively), whereas central scar was the most specific feature (90.6%). The presence of two or more of the classic histological features had 89.6% sensitivity and 86.2% specificity for a diagnosis of FNH. Diagnostic accuracy was significantly higher with the addition of a GS stain. A map‐like GS staining pattern was highly specific (99.3%) for FNH. However, GS staining was interpreted as non‐map‐like in 14.4% of reviews of true FNH cases, and overall interobserver agreement for interpretation of the GS staining pattern was only moderate (kappa = 0.42).ConclusionsPathologists are reasonably accurate in the diagnosis of FNH on virtual biopsies, and GS staining improves accuracy. However, a subset of FNH cases remain challenging. Steatosis and a pseudo‐map‐like GS staining pattern were associated with increased difficulty. Therefore, although a map‐like GS staining pattern is useful for confirmation of a diagnosis, the lack of a map‐like GS staining pattern on needle biopsy does not necessarily exclude a diagnosis of FNH.

AbstractThis article is the result of the North American Neuroendocrine Tumor Society consensus conference on the medical management of pancreatic neuroendocrine tumors from July 19 to 20, 2018. The guidelines panel consisted of medical oncologists, pathologists, gastroenterologists, endocrinologists, and radiologists. The panel reviewed a series of questions regarding the medical management of patients with pancreatic neuroendocrine tumors as well as questions regarding surveillance after resection. The available literature was reviewed for each of the question and panel members voted on controversial topics, and the recommendations were included in a document circulated to all panel members for a final approval.

AbstractObjectivesSteatohepatitic hepatocellular carcinoma is a distinct variant of hepatocellular carcinoma strongly associated with underlying nonalcoholic steatohepatitis. The molecular biology of steatohepatitic hepatocellular carcinoma is not fully elucidated, and thus we aimed to investigate the molecular underpinnings of this entity.MethodsTranscriptomic analysis using RNAseq was performed on eight tumor-nonneoplastic pairs of steatohepatitic hepatocellular carcinoma with comparison to conventional hepatocellular carcinoma transcriptomes curated in The Cancer Genome Atlas. Immunohistochemistry was used to validate key RNA-level findings.ResultsSteatohepatitic hepatocellular carcinoma demonstrated a distinctive differential gene expression profile compared with The Cancer Genome Atlas curated conventional hepatocellular carcinomas (n = 360 cases), indicating the distinctive steatohepatitic hepatocellular carcinoma morphology is associated with a unique gene expression profile. Pathway analysis comparing tumor-nonneoplastic pairs revealed significant upregulation of the hedgehog pathway based on GLI1 overexpression and significant downregulation of carnitine palmitoyltransferase 2 transcript. Glutamine synthetase transcript was significantly upregulated, and fatty acid binding protein 1 transcript was significantly downregulated and immunohistochemically confirmed, indicating steatohepatitic hepatocellular carcinoma tumor cells display a zone 3 phenotype.ConclusionsSteatohepatitic hepatocellular carcinoma demonstrates a distinctive morphology and gene expression profile, phenotype of zone 3 hepatocytes, and activation of the hedgehog pathway and repression of carnitine palmitoyltransferase 2, which may be important in tumorigenesis.

Abstract Background: The IMpassion130 study demonstrated prolonged overall survival when atezolizumab, a PD-L1 inhibitor, was added to nab-paclitaxel in PD-L1 positive patients with advanced triple negative breast cancer (TNBC). Approximately 40% of tumors were PD-L1 positive, utilizing a cutoff of ≥ 1% immune cell (IC) staining with the Ventana SP142 immunohistochemical (IHC) assay. The Food and Drug Administration (FDA) approved this assay as a companion test to determine patient eligibility for atezolizumab therapy. However, literature in lung cancer shows that pathologists have a high discordance in assessing PD-L1 on IC. The FDA companion test documentation for SP142 shows high inter-laboratory reproducibility with nearly 95% overall percent agreement (OPA) between 2 readers for 2 category scoring of IC (positive versus negative) in TNBC in a central laboratory. PD-L1 testing for breast cancer is now becoming widespread in pathology laboratories. The goal of this study was to assess concordance in PD-L1 scoring between 19 pathologists from 14 institutions examining the same 86 TNBC tissues stained with the SP142 and SP263 antibodies. We also present a new method to determine the minimum number for evaluators needed to estimate concordance between large numbers of readers as occurs in real life setting. Methods: Full tissue sections were stained exactly as prescribed on the label on the Ventana Benchmark with the SP142 and SP263 PD-L1 assays. Sixty-eight and 76 cases were evaluable respectively. Stained slides were scanned and digital files distributed to pathologists who independently scored cases as either negative (&lt; 1% IC staining) or positive (≥ 1% IC staining) and estimated the % of IC staining for positive cases. We applied a method that we call Observers Needed to Evaluate Subjective Tests (ONEST). For any combination of pathologists, we can quantify the degree of overall agreement using the proportion of tissue samples upon which all selected pathologists agreed, which can lead to a plot of non-increasing trajectory of agreement as the number of pathologists increases. We computed and plotted the empirical estimate of the overall agreement with the 95% confidence interval (CI) from 1000 randomly selected permutations of the pathologists. Results: PD-L1 was interpreted as positive with SP263 in an average of 78% of cases compared to 58% with the SP142 assay (p&lt;.0001). IC positive continuous scores ranged from 1-95% (mean=20%) and 1-90% (mean=10%) for SP263 and SP142. Complete 2 category (positive vs negative) scoring concordance across all observers was achieved in 38 cases (50%) with SP263 and 26 cases (38%) with SP142. The intraclass correlation coefficient (ICC) for 2 category scoring of SP263 and SP142 was 0.513 and 0.560 respectively. ONEST plots made for each assay for 19 pathologists showed a decrease in OPA as number of observers increased, reaching a low plateau of approximately 0.46 at 10 observers for SP263 and 0.42 at 8 observers for SP142. Conclusions: Utilizing the FDA approved SP142 assay, we found a higher prevalence of PD-L1 positive tumors than published in the IMpassion130 trial but lower prevalence than seen with the SP263 assay. The different proportion of positive cases seen with two different assays highlights the need to establish cutoffs for each assay to correspond with clinical benefit. The ICC of scoring immune cells with both PD-L1 assays showed poor reproducibility across multiple pathologists. The ONEST analysis finds a plateau with 10 pathologists, only reaching an OPA of 0.4 for immune cell assessment. This suggests that more than half of the pathologists in real world situations may mis-assign patient IC scores. This could lead to a high percentage of patients either receiving atezolizumab, when they are unlikely to benefit or not receiving atezolizumab when they may benefit. Citation Format: Emily Suzanne Reisenbichler, Gang Han, Vasiliki Pelekanou, Vesal Yaghoobi, Fahad S Ahmed, Andrew Bellizzi, Veerle Bossuyt, Jane Brock, Kimberly Cole, Oluwole Fadare, Omar Hameed, Krisztina Hanley, Beth T Harrison, M G Kuba, Amy Ly, Dylan Miller, Mirna Podoll, Anja C Roden, Mary A Sanders, Kamaljeet Singh, Shi Wei, Hannah Wen, Lajos Pusztai, David L Rimm. Prospective multi-institutional evaluation of pathologist assessment of PD-L1 assays in triple negative breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD5-01.