K-ras mutation is frequently detected in pancreatic juice of patients with pancreatic small cystic lesions, as well as those with pancreatic cancer.
Those cystic lesions are often found by chance with modern radiologic imaging modalities.
Dr Minoru Tada and colleagues from Japan prospectively examined the prognosis of patients with pancreatic cystic lesions.
The team focused on pancreatic cancer development.
The researchers evaluated a total of 197 patients with pancreatic cystic lesions.
|The standardized incidence rate was 23|
|Clinical Gastroenterology & Hepatology|
Of these, 80 had intraductal papillary mucinous neoplasm, and 117 with non-intraductal papillary mucinous neoplasm cysts.
The patients were followed up for 4 years on average.
Blood tests and imaging diagnosis were performed twice a year.
The observed incidence of pancreatic cancer was compared with the expected incidence.
The team calculated this on the basis of age- and gender-matched mortality of pancreatic cancer in the general Japanese population.
Pancreatic cancer developed in 7 patients during the observation period.
The team noted that the cancer presented as infiltrating ductal carcinoma in 5 and intraductal papillary mucinous carcinoma in 2.
The researchers found that 3 of the ductal cancer cases had pancreatic non-intraductal papillary mucinous cyst as preexisting lesion.
The research team observed at least 2 of the carcinomas arose in regions remote from preexisting lesions.
The observed incidence of pancreatic cancer was 23 times higher than expected mortality from this cancer among general population.
Dr Tada's team concludes, “Patients with pancreatic cystic lesions are at a considerably high risk for pancreatic cancer, with a standardized incidence rate of 23.”
“Cancer might develop in regions remote from the preexisting cystic lesion.”
“This suggests diffuse pathologic changes predisposing to malignant transformation in the entire pancreas harboring cystic lesions.”