Single-pattern convergence of K-ras mutation correlates with surgical indication of intraductal papillary mucinous neoplasms.
OBJECTIVE
One or more patterns of 6 K-ras mutations are detected in cells from the pancreatic juice of patients with intraductal papillary mucinous neoplasms (IPMNs). We investigated whether these mutations are associated with malignant progression.


METHODS
Between January 2002 and December 2007, 53 patients with IPMN were subjected to collection of pure pancreatic juice to evaluate K-ras mutation. According to the histological and radiological findings, the IPMNs were classified into 4 groups: carcinoma group, adenoma group, high-risk group, and low-risk group. We retrospectively investigated the mutation with these groups.


RESULTS
In patients with a positive K-ras mutation, a single pattern of K-ras mutation was observed in 80% (8/10) of the carcinoma group, in 71% (5/7) of the adenoma group, in 40% (2/5) of the high-risk group, and in 38% (8/21) of the low-risk group. The rate of a single pattern of K-ras mutation decreased in a stepwise order (P = 0.017). The incidence of a single pattern of K-ras mutation was significantly higher in the patients who received surgical therapy (75%, 12/16) than in those who did not (38%, 10/26; P = 0.033).


CONCLUSIONS
The present study suggests that the single-clonal convergence of K-ras mutation is associated with the malignant progression of IPMNs.
Mizuno
Osamu
O
Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
Kawamoto
Hirofumi
H
Yamamoto
Naoki
N
Horiguchi
Shigeru
S
Tsutsumi
Koichiro
K
Fujii
Masakuni
M
Kato
Hironari
H
Hirao
Ken
K
Kurihara
Naoko
N
Ishida
Etsuji
E
Ogawa
Tsuneyoshi
T
Okada
Hiroyuki
H
Yamamoto
Kazuhide
K
D002288:Adenocarcinoma, Mucinous / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D000368:Aged; D021441:Carcinoma, Pancreatic Ductal / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D002291:Carcinoma, Papillary / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D018450:Disease Progression; D005260:Female; D011905:Genes, ras; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010189:Pancreatic Juice; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D012189:Retrospective Studies