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Updated: Jul 7, 2026
A Model for Perineural Invasion in Head and Neck Squamous Cell Carcinoma
Published on: January 5, 2017
HNPCC-associated small bowel cancer: clinical and molecular characteristics
Karsten Schulmann1, Frank E Brasch, Erdmute Kunstmann
1Department of Medicine, Knappschaftskrankenhaus, Ruhr-University Bochum, Bochum, Germany.
Background & Aims:
The risk for small bowel cancer (SBC) is significantly increased in hereditary nonpolyposis colorectal cancer (HNPCC). HNPCC-associated SBCs are poorly characterized.
Methods:
Thirty-two SBCs were characterized according to clinical, pathologic, and germline mutation data. Histomorphologic characteristics, microsatellite instability (MSI) testing, mismatch repair (MMR) protein expression, and frameshift mutations of 7 coding mononucleotide repeats were investigated in 17 SBCs.
Results:
Median age at diagnosis was 39 years. Fifty percent of SBCs were located in the duodenum. The Amsterdam criteria were fulfilled in 50% of patients; 45% of patients had no personal history of previous malignancies. Two patients had a positive family history for SBC. Pathogenic germline mutations were identified in 81%; high MSI was detected in 95% and loss of MMR protein expression in 89% of cases. TGFBR2 , BAX , MSH3 , MSH6 , ACVR2 , AIM2 , and SEC63 frameshift mutations were detected in 69%, 59%, 59%, 35%, 82%, 56%, and 56%, respectively. An expansive growth pattern of the tumor border and an intense intratumoral lymphocytic infiltrate were present in 75%, respectively.
Conclusions:
HNPCC-associated SBC often manifests at a young age and may be the first disease manifestation. Endoscopy may detect 50% of tumors. Considering recent data on gastric cancer, we propose endoscopic screening of mutation carriers starting at 30 years of age because clinical criteria cannot define a high-risk group. In addition, our study shows that histopathologic criteria, MSI, and MMR immunohistochemistry are often similar to these features in HNPCC.
