title: Colorectal carcinomas with submucosal invasion (pT1): analysis of histopathological and molecular factors predicting lymph node metastasis.
abstract: Submucosally invasive colorectal carcinoma (pT1) has the potential to be cured by local excision. In US surgical intervention is reserved for tumors with high-grade morphology, lymphvascular invasion, and close/positive margin. In other countries, particularly Japan, surgical therapy is also recommended for mucinous tumors, tumors with >1000 μm of submucosal invasion, and those with high tumor budding. These histological features have not been well evaluated in a western cohort of pT1 carcinomas. In a cohort of 116 surgically resected pT1 colorectal carcinomas, high tumor budding (P<0.001), lymphatic invasion (P=0.003), depth of submucosal invasion >1000 μm (P=0.04), and high-grade morphology (P=0.04) were significantly associated with lymph node metastasis on univariate analysis. Mucinous differentiation, tumor location, tumor growth pattern, and size of invasive component were not significant. On multivariate analysis, only high tumor budding was associated with lymph node metastasis with an odds ratio of 4.3 (P=0.004). A subset of 48 tumors (22 node-positive and 26 node-negative) was analyzed for mutations in 50 oncogenes and tumor suppressors. No statistically significant molecular alterations in these 50 genes were associated with lymph node status. However, lymphatic invasion was associated with BRAF mutations (P=0.01). Furthermore, high tumor budding was associated with mutations in TP53 (P=0.03) and inversely associated with mutations in the mTOR pathway (PIK3CA and AKT, P=0.02). In conclusion, this study demonstrates the importance of identifying high tumor budding in pT1 carcinomas when considering additional surgical resection. Molecular alterations associated with adverse histological features are identified.
authors.affiliation: Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: Reetesh K
authors.initials: RK
authors.lastname: Pai
authors.affiliation: Department of Pathology, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Yu-Wei
authors.initials: YW
authors.lastname: Cheng
authors.affiliation: Department of Pathology, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Maureen A
authors.initials: MA
authors.lastname: Jakubowski
authors.affiliation: Department of Pathology, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Bonnie L
authors.initials: BL
authors.lastname: Shadrach
authors.affiliation: Department of Pathology, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Plesec
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Scottsdale, AZ, USA.
authors.forename: Rish K
authors.initials: RK
authors.lastname: Pai
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics; D058534:Class I Phosphatidylinositol 3-Kinases / Q000235:genetics; D015179:Colorectal Neoplasms / Q000235:genetics / Q000473:pathology*; D006801:Humans; D008207:Lymphatic Metastasis / Q000235:genetics / Q000473:pathology*; D053842:Microsatellite Instability; D008875:Middle Aged; D009154:Mutation; D009361:Neoplasm Invasiveness / Q000235:genetics / Q000473:pathology*; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D058534:Class I Phosphatidylinositol 3-Kinases; C484760:PIK3CA protein, human; D051057:Proto-Oncogene Proteins c-akt