The time of occurrence of liver metastasis in carcinoma of the pancreas.

By measuring the doubling time of liver metastasis, the authors investigated the possibility of occult liver metastasis at the time of pancreatectomy in patients with pancreatic carcinoma. We calculated tumor doubling times of liver metastases in six patients after pancreatectomy for periampullary carcinoma and compared with cell doubling times. We also calculated the diameters of the occult liver metastases at the time of pancreatectomy on the assumption that the growth rates of liver metastasis were constant. Tumor doubling times of liver metastases in six patients were 34, 32, 318, 108, 78, and 27 d, respectively. In two of these patients, tumor doubling times, compared with cell doubling times of 51 and 52 h for PK-36 and PK-59 established from the same patients with carcinoma of the pancreas, were about 15 times as long as those of cultured cell lines. The calculated sizes of the occult liver metastases at the time of pancreatectomy in these six patients were 2.4, 0.14, 19.0, 8.2, 3.5, and 4.2 mm. In five of these six patients, the calculated sizes were in the range between 10 microns and 1 cm. These results indicated occult liver metastases had already existed in patients with carcinoma of the pancreas at the time of pancreatectomy and were too small to be detected by imaging technique. We cannot improve survival rates in carcinoma of the pancreas by surgical management alone. For further improvement in survival rate of patients with carcinoma of the pancreas to occur, effective adjuvant therapies to prevent liver metastases must complement surgical management.