Clinicopathological Features of 15 Occult and 178 Clinical Pancreatic Ductal Adenocarcinomas in 8339 Autopsied Elderly Patients

Objective The aim of the study was to investigate the clinicopathological features of pancreatic cancer at different stages using autopsy results. Methods We retrospectively evaluated 8399 consecutive cases of autopsy performed between 1972 and 2013 at our geriatric hospital. Results Macroscopic pancreatic lesions were detected in 6.13% of the cases. Primary and secondary pancreatic tumors were observed in 2.88% and 2.10% of the cases, respectively. Most primary tumors were invasive ductal adenocarcinomas (193 cases [2.31%]; mean patient age, 78.09 years) with a peak incidence at 50 to 59 years. Occult invasive ductal adenocarcinoma was discovered incidentally in 15 cases, with distant metastasis present in 26.67% of those. Microscopically, occult and advanced tumors exhibited similar characteristics such as hyalinized fibrous stroma, necrosis, invasion into vessels, peripancreatic fat tissues, and extrapancreatic nerve plexus. Mucin 1 and 2 immunohistochemical expression levels were also similar. Occult cancer incidence increased with age. Patients aged 85 years or older had shorter survival, a small tumor size, and a low incidence of lymph node metastasis. Approximately 8% of pancreatic invasive ductal adenocarcinomas progressed asymptomatically and were discovered incidentally at autopsy. Conclusions Pancreatic cancers in elderly patients tend to progress asymptomatically, but once symptoms develop, they are more often fatal than those in younger patients.