title: Clinical features and molecular alterations of traditional serrated adenoma in sporadic colorectal carcinogenesis.
abstract: OBJECTIVE
  To compare clinical features and molecular alterations between traditional serrated adenomas (TSA) & serrated carcinomas (SCa) and traditional adenomas (TA) & carcinomas (Ca) of the colorectum and to verify a traditional serrated pathway of sporadic colorectal carcinogenesis.
  
  
  METHODS
  One thousand two hundred slides of colorectal polyps obtained from 1160 patients were collected and reviewed to define TSA and clinical and pathological features were analyzed and compared with TA. DNA was extracted from specimens of TSA, TA, SCa and Ca, v-raf murine sarcoma viral oncogene homolog B (BRAF) V600E mutation and microsatellite instability (MSI) (assay for BAT25 and BAT26) were analyzed.
  
  
  RESULTS
  Overall 29 TSA were confirmed (2.5%), and there was an age difference between patients with TSA and TA (56.0 vs 62.7, P<0.05). Compared with TA, TSA was located more often in the rectosigmoid colon (TSA 62.1% vs TA 35.2%, P<0.05), but occurred less in the descending colon (TSA 0% vs TA 25.35%, P=0.0068). No difference was found in terms of gender and the size or pedicles of polyps (P>0.05). The BRAF V600E mutation was detected in 36.3% of SCa and 26.7% of TSA patients, but it was not detected in TA and Ca patients; MSI-H was noticed in 23% of SCa, 33.3% of TSA, 5.3% of Ca and 0% of TA patients, respectively (P<0.05).
  
  
  CONCLUSIONS
  There might be a traditional serrated pathway of sporadic colorectal carcinogenesis that is different from the conventional adenoma to carcinoma carcinogenesis pathway in the colorectum.
authors: Department of Gastroenterology, People's Liberation Army, The Military General Hospital of Beijing, Beijing, China.
authors: Ying
authors: Y
authors: Han
authors: Zhi Yong
authors: ZY
authors: Zhou