Observations on the developmental patterns and the consequences of pancreatic exocrine adenocarcinoma. Findings of 154 autopsies.

OBJECTIVE: To improve our future care of the patient with exocrine pancreatic cancer by seeking, within the limitations of our present approaches, additional information on the growth and spread of the cancer and its influences on the patient.
DESIGN: Consecutive autopsies of all patients with exocrine pancreatic cancer were reviewed retrospectively by two surgeons and three pathologists. SETTINGS: Three teaching hospitals of the Medical College of Ohio, Toledo. MATERIALS: One hundred fifty-four consecutive autopsies of patients with exocrine pancreatic cancer during the period between 1952 and 1992.
RESULTS: Intrapancreatic metastases or multicentric cancers were found in 12 patients. In 32 patients, pancreatic cancer skipped the lymph nodes, primarily draining the respective areas of the pancreas to metastasize to the secondary chain of nodes. In 13 patients, pulmonary metastases occurred without hepatic metastasis. Intrapancreatic contiguous extension was identified in 34 patients. Carcinoma of the body and/or tail of the pancreas was characterized by transperitoneal as well as hematogenous dissemination to a greater extent than was carcinoma of the head of the pancreas. Seven of 11 small tumors (< 2 cm in diameter) were associated with remote metastases. Relatively severe chronic obstructive pancreatitis was found to have resulted from pancreatic carcinoma in 18 cases, whereas in seven patients, pancreatic carcinoma probably developed in preexisting chronic pancreatitis. Thromboembolic disease was found in 30 patients, more frequently in the patients with the mucin-producing tumors of the pancreatic body and tail. In 21 patients, the amount of ascites was not proportional to the severity of peritoneal dissemination, vessel invasion, or recognizable hepatic dysfunction. Thromboembolic disease, severe infection, stress ulcer, and acute hemorrhagic erosive gastroenteritis were frequent systemic complications contributing to death. Malnutrition in the form of cachexia was undoubtedly a major, even dominant, feature in many patients that could not be quantitated from this data.
CONCLUSIONS: Metastasizing cells frequently bypass the initial filters in lymph nodes, liver, or lung to become established in secondary or tertiary sites. Intrapancreatic metastases or multicentric tumors also may develop more frequently than generally has been recognized. Small cancers (< 2 cm in diameter) are often associated at autopsy with remote metastases. These facts would appear to limit the usefulness of the current staging of resected cancers of the pancreas. Cancers of the body or tail are characterized by transperitoneal and hematogenous spread to a greater extent than are those of the head. Anatomical studies often do not explain the cause or the extent of ascites associated with pancreatic adenocarcinoma. As previously indicated, chronic pancreatitis appears to be further confirmed as a precursor of pancreatic cancer.