Pseudoinvasion (PI) is a benign lesion in which cancer is mimicked in the colon by misplacement of dysplastic glands in the submucosa. Although there are morphological clues, the discrimination of... Show morePseudoinvasion (PI) is a benign lesion in which cancer is mimicked in the colon by misplacement of dysplastic glands in the submucosa. Although there are morphological clues, the discrimination of PI from true invasion can be a challenge during pathological evaluation of colon adenomas. Both overdiagnosis and underdiagnosis can result in inadequate clinical decisions. This calls for novel tools to aid in cases where conventional methods do not suffice. We performed mass spectrometry imaging (MSI)-based spatial glycomics analysis on a cohort of formalin-fixed paraffin-embedded tissue (FFPE) material from 16 patients who underwent polypectomy. We used this spatial glycomic data to reconstruct the molecular histology of the tissue section using spatial segmentation based on uniform manifold approximation and projection for dimension reduction (UMAP). We first showed that the spatial glycomic phenotypes of the different morphological entities separated as distinct clusters in colon tissues, we separated true invasion from the other morphological entities. Then, we found that the glycomic phenotype in areas with suspected PI in the submucosa was strongly correlating with the corresponding glycomic phenotype of the adenomatous colon epithelium from the same tissue section (Pearson correlation distance average = 0.18). These findings suggest that using spatial glycomics, we can distinguish PI as having a molecular phenotype similar to the corresponding surface epithelium and true invasion as having a different phenotype even when compared to high-grade dysplasia. Therefore, when a novel molecular phenotype is found in the deepest submucosal region, this may be used as an argument in favor of true invasion. Show less
BACKGROUND & AIMS: Recent pancreatic cancer surveil-lance programs of high-risk individuals have reported improved outcomes. This study assessed to what extent outcomes of pancreatic ductal... Show moreBACKGROUND & AIMS: Recent pancreatic cancer surveil-lance programs of high-risk individuals have reported improved outcomes. This study assessed to what extent outcomes of pancreatic ductal adenocarcinoma (PDAC) patients with a CDKN2A/p16 pathogenic variant diagnosed under surveillance are better as compared with patients with PDAC diagnosed outside surveillance.METHODS: In a pro-pensity score matched cohort using data from the Netherlands Cancer Registry, we compared resectability, stage, and survival between patients diagnosed under sur-veillance with non-surveillance patients with PDAC. Survival analyses were adjusted for potential effects of lead time.RESULTS: Between January 2000 and December 2020, 43,762 patients with PDAC were identified from the Netherlands Cancer Registry. Thirty-one patients with PDAC under surveillance were matched in a 1:5 ratio with 155 non surveillance patients based on age at diagnosis, sex, year diagnosis, and tumor location. Outside surveillance, 5.8% of the patients had stage I cancer, as compared with 38.7% of surveillance patients with PDAC (odds ratio [OR], 0.09; 95% confidence interval [CI], 0.04-0.19). In total, 18.7% of non surveillance patients vs 71.0% of surveillance patients un- derwent a surgical resection (OR, 10.62; 95% CI, 4.56-26.63). Patients in surveillance had a better prognosis, reflected by 5-year survival of 32.4% and a median overall survival of 26.8 months vs 4.3% 5-year survival and 5.2 months median overall survival in non-surveillance patients (hazard ratio, 0.31; 95% CI 0.19-0.50). For all adjusted lead times, survival remained significantly longer in surveillance patients than non-surveillance patients.CONCLUSION: Surveillance for PDAC in carriers of a CDKN2A/p16 pathogenic variant results in earlier detection, increased resectability, and improved survival as compared with non-surveillance patients with PDAC. Show less
