Early onset esophageal adenocarcinoma: a distinct molecular entity?

Esophageal adenocarcinoma (EAC) is typically diagnosed in elderly with a median age of 68 years. The incidence of EAC has been rising over the last decades, also among young adults. The aim of the study was to investigate whether early onset EAC is a distinct molecular entity. To identify early onset EACs, the nationwide network and registry of histo- and cytopathology in the Netherlands (PALGA) was searched. Twenty-eight tumors of patients aged ≤40 years were selected and matched with 27 tumors of patients aged ≥68 years. DNA was isolated from surgically resected specimen and sequenced on the Ion Torrent Personal Genome Machine with the Ion AmpliSeq Cancer Panel. No differences in mutational load between early onset and conventional EACs were observed (P=0.196). The most frequently mutated genes were TP53 (73%) and P16 (16%). Additional mutations in early onset EACs occurred exclusively in: APC, CDH1, CTNNB1, FGFR2, and STK11. In the conventional EACs additional mutations were exclusively identified in: ABL1, FBXW7, GNA11, GNAS, KRAS, MET, SMAD4, and VHL. Additional mutations besides TP53 and P16 seem to occur in different genes related to cell fate pathways for early onset EACs, while the additional mutations in conventional EACs are related to survival pathways

Prognostic Factors in a Large Nationwide Cohort of Histologically Confirmed Primary and Secondary Angiosarcomas

Angiosarcoma (AS) is a rare sarcoma of endothelial origin, arising spontaneously (primary AS) or after external damage such as radiation therapy or UV exposure (secondary AS). To date, reliable assessment of prognostic factors has proven difficult, due to disease rarity and heterogeneity of study cohorts. Although large registries provide relatively large AS patient series, these cases often lack histological confirmation. This study aimed to analyze AS prognostic factors in a large nationwide cohort of histologically confirmed cases, established through linkage of clinical data from the Netherlands Cancer Registry and pathology data from the Dutch pathology registry (PALGA). All cases were reviewed by an expert pathologist, showing a 16% discordance rate. Multivariable Cox regression survival analysis among 479 confirmed AS patients revealed remarkably poorer overall survival (OS) for primary AS compared to secondary AS (7 vs 21 months, Hazard ratio (HR) = 1.5; 95% confidence interval (CI) = 1.2–1.9). Age above 65 years, male gender, and no surgical treatment also significantly correlated to worse OS. Overall, OS was relatively poor, with a median of 13 months (95% CI = 10–16 months) and 22% five-year survival rate. With this study, we illustrate AS heterogeneity in clinical behavior and show for the first time better survival for secondary AS compared to primary AS

Pathology review identifies frequent misdiagnoses in recurrent classic Hodgkin lymphoma in a nationwide cohort:implications for clinical and epidemiological studies

Patients treated for classic Hodgkin lymphoma (CHL) have a reported 13-fold increased risk of developing subsequent non-Hodgkin lymphoma (NHL). In light of the growing awareness of CHL mimickers, this study re-assesses this risk based on an in-depth pathology review of a nationwide cohort of patients diagnosed with CHL in the Netherlands (2006-2013) and explores the spectrum of CHL mimickers. Among 2,669 patients with biopsy-proven CHL, 54 were registered with secondary NHL. On review, CHL was confirmed in 25/54 patients. In six of these, the subsequent lymphoma was a primary mediastinal B-cell lymphoma/mediastinal gray zone lymphoma, biologically related to CHL and 19/25 were apparently unrelated B-cell NHL. In 29/54 patients, CHL was reclassified as NHL, including T-cell lymphomas with secondary Hodgkin-like B-blasts (n=15), Epstein Barr virus-positive diffuse large B-cell lymphoma (n=8), CD30+ T-cell lymphoma (n=3) and indolent B-cell proliferations (n=3). Higher age, disseminated disease at presentation, extensive B-cell marker expression and association with Epstein-Barr virus were identified as markers to alert for CHL mimickers. Based on these data, the risk of developing NHL after CHL treatment was re-calculated to 3.6-fold (standardized incidence ratio 3.61; confidence interval: 2.29-5.42). In addition, this study highlights the clinicopathological pitfalls leading to misinterpretation of CHL and consequences for the care of individual patients, interpretation of trials and epidemiological assessments.</p

Prevalence and prognostic value of PD-L1 expression in molecular subtypes of metastatic large cell neuroendocrine carcinoma (LCNEC)

Background: Pulmonary large cell neuroendocrine carcinoma (LCNEC) is a rare tumor with high mutational burden. Two subtypes of LCNEC are recognized, the co-mutated TP53 and RB1 group and the TP53 and STK11/KEAP1 group. We investigated PD-L1 and CD8 expression in a well characterized stage IV LCNEC cohort and compared expression in the two subtypes. Methods: Immunohistochemical (IHC) analysis for PD-L1 and CD8 was performed on pathological reviewed pretreatment tumor samples for 148 stage IV LCNEC. Data about targeted next generation sequencing (TNGS) (TP53, RB1, STK11, KEAP1) and IHC for RB1 were available for most tumors. IHC staining for PD-L1 (DAKO 28-8) was performed and scored positive if tumors showed ≥1% membranous staining. CD8 was scored for intra-tumor T-cells and stromal cells. Results: PD-L1 IHC expression data could be generated in 98/148 confirmed LCNEC samples along with RB1 IHC (n = 97) of which 77 passed quality control for TNGS. PD-L1 expression was positive in 16/98 cases (16%); 5 (5%) with ≥50%. PD-L1 expression was equal in RB1 mutated and RB1 wildtype tumors. None of STK11 mutated tumors (n = 7) expressed PD-L1. PD-L1 expression was correlated with superior overall survival (OS), hazard ratio 0.55 ((95% Confidence Interval 0.31-0.96), p = 0.038). Intra-tumor CD8 was associated with PD-L1 expression (p = 0.021) and stromal and intra-tumor CD8 were correlated with improved OS (p = 0.037 and p = 0.026 respectively). Conclusions: PD-L1 expression was positive in 16% of stage IV LCNEC tumors. This was independent of molecular subtype but associated with CD8 expression. In LCNEC patients with PD-L1 and/or CD8 expression superior OS was observed

Hepatocellular adenoma in men

Background &amp; Aims: Hepatocellular adenomas (HCA) rarely occur in males, and if so, are frequently associated with malignant transformation. Guidelines are based on small numbers of patients and advise resection of HCA in male patients, irrespective of size or subtype. This nationwide retrospective cohort study is the largest series of HCA in men correlating (immuno)histopathological and molecular findings with the clinical course. Methods: Dutch male patients with available histological slides with a (differential) diagnosis of HCA between 2000 and 2017 were identified through the Dutch Pathology Registry (PALGA). Histopathology and immunohistochemistry according to international guidelines were revised by two expert hepatopathologists. Next generation sequencing (NGS) was performed to confirm hepatocellular carcinoma (HCC) and/or subtype HCA. Final pathological diagnosis was correlated with recurrence, metastasis and death. Results: A total of 66 patients from 26 centres fulfilling the inclusion criteria with a mean (±SD) age of 45.0 ± 21.6 years were included. The diagnosis was changed after expert revision and NGS in 33 of the 66 patients (50%). After a median follow-up of 9.6 years, tumour-related mortality of patients with accessible clinical data was 1/18 (5.6%) in HCA, 5/14 (35.7%) in uncertain HCA/HCC and 4/9 (44.4%) in the HCC groups (P =.031). Four B-catenin mutated HCA were identified using NGS, which were not yet identified by immunohistochemistry and expert revision. Conclusions: Expert revision with relevant immunohistochemistry may help the challenging but prognostically relevant distinction between HCA and well-differentiated HCC in male patients. NGS may be more important to subtype HCA than indicated in present guidelines.</p