[Adenocarcinoma of the pancreas. General characteristics].

EPIDEMIOLOGY

Pancreatic carcinoma ranks fifth among the leading causes of cancer death in developed countries. Although the incidence of pancreatic cancer is about 10 per 100,000 inhabitants, the five-year overall survival is barely one to 4%. Few risk factors have been identified. Smoking increases the relative risk by 1.5, chronic pancreatitis by 26. Hereditary formes are rare.

PATHOLOGY AND MOLECULAR ABNORMALITIES

Adenocarcinomas of the ductal phenotype represents about 90% of the pancreatic tumors. Seventy percent of adenocarcinomas are located in the head. Mutations of K-ras oncogene and p53 anti-oncogene are noted, respectively, in 80 to 90% and 70% of the ductal adenocarcinomas. The mutation of p53 is associated with a poor prognosis. Certain less frequent forms such as mucinous cystadenocarcinomas, or intraductal papillary-mucinous tumors seem to have a better prognosis. However, this is not true for acinar cell carcinomas responsible for various paraneoplastic syndromes.

PATTERN OF SPREAD

The disease arises in the ductal epithelium and rapidly spreads to regional lymph nodes and the liver. At diagnosis, nodal involvement is found in 80% of cases. Half of the patients have detectable visceral metastasis with a median survival of three to six months. Among the remaining non metastatic patients, approximately one in 5 has undetected peritonal carcinomatosis. Only 10 to 20% of the patients undergo surgical complete resection with a median survival of 15 to 19 months.