THE TIME OF OCCURRENCE OF LIVER METASTASIS IN CARCINOMA OF THE PANCREAS

By measuring the doubling time of liver metastasis, the authors invest igated the possibility of occult liver metastasis at the time of pancr eatectomy in patients with pancreatic carcinoma. We calculated tumor d oubling 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 t ime 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 tw o 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 pa tients 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, t he calculated sizes were in the range between 10 mu m and 1 cm. These results indicated occult liver metastases had already existed in patie nts with carcinoma of the pancreas at the time of pancreatectomy and w ere too small to be detected by imaging technique. We cannot improve s urvival rates in carcinoma of the pancreas by surgical management alon e. For further improvement in survival rate of patients with carcinoma of the pancreas to occur, effective adjuvant therapies to prevent liv er metastases must complement surgical management.