Clinical Significance of the Actual Half-life of Serum Alpha-fetoprotein in Primary Hepatocellular Carcinoma

PURPOSE: We observed the actual half life of the alpha-fetoprotein (AFP) had clinical meaning in that it reflected the long term prognosis more individually at a certain level of preoperative alpha-fetoprotein. METHODS: From preoperative and postoperative measurements of alpha-fetoprotein in 96 hepatocellular carcinomas the actual half lives were calculated with the formula: AHL T1/2 (days) = -0.3x(T/log(C1/C0)), where T was the time interval between C1 and C0, in which C1 meant the level of AFP at postoperative 7 day, C0 the original AFP level. We investigated overall survival and disease free survival rate between delayed AHL group and non-delayed AHL group under various definitions of delay. RESULTS: The average actual half life of all cases was 5.1+/-13.6 days. One, three and five year overall survival rates of the group with actual half life less than 4 days were 82.1%, 66.7%, 61.1% respectively, whereas those of the group with actual half life more than 4 days showed 83.0%, 36.5%, 18.2% respectively. The significance of different survival rates was much higher, when only the patients with preoperative alpha-fetoprotein above 100 ng/ml were taken into account (n=53, P=0.0019). The disease free five year survival rates were also significantly different. CONCLUSION: We can predict the elevated postoperative survival rate in the patients with actual half life of alpha-fetoprotein less than 4 days. And this has also relevant clinical meaning in the prognostication of disease free survival, if the preoperative alpha-fetoprotein of patients has elevated up to over 100 ng/ml. The measurement of actual half life of postoperative hepatocellular carcinoma patientscan be a clinical useful parameter for the prognosis of long term survival.

Actual Half-Life of Alpha-Fetoprotein as a Prognostic Tool in Pediatric Malignant Tumors

In a retrospective study, the prognostic value of monitoring the decay of alpha-fetoprotein (AFP) was assessed. Serum AFP was determined serially in 18 children with malignant germ cell tumors or malignant hepatic tumors: Fifteen children had malignant germ cell tumors (endodermal sinus tumor;7, embryonal carcinoma;3, malignant teratoma;5). Two children had hepatoblastoma and a third had hepatocellular carcinoma. The actual half-life (AHL) of AFP was computed according to the formula after the surgical resection of the tumor. In group 1, which had a complete resection and no recurrence during follow-up (n=13), the AHL of AFP was 4.0+/-0.9 days. In group 2, which had a incomplete resection or recurrence during follow-up (n=5), the AHL of AFP was 24.8+/-20 days. The AHL of group 2 was significantly longer than that of group 1 (p = 0.0026). The increased AHL of AFP indicated the residual active tumor after surgical resection. The AHL of AFP may be more sensitive than the serial monitoring of AFP in detecting the preclinical recurrence after surgical resection of AFP secreting tumors. Treatment strategies can be based on AFP clearance and prospective clinical trials are warranted.

Significance of postoperative serum level of carcinoembryonic antigen (CEA) and actual half life of CEA in colorectal cancer patients

The postoperative levels of carcinoembryonic antigen (CEA) and the actual half life (T1/2) of CEA were evaluated to ascertain their potency in predicting the recurrence of colorectal cancer after curative surgery in patients who had an abnormally high level of preoperative carcinoembryonic antigen (CEA, > or = 5 ng/ml). Ninety-four patients who underwent curative surgery were enrolled and 24 patients (25.5%) had recurrence during the follow-up period (median: 30 months, range: 2-69 months). T1/2 of CEA for all patients ranged from 1.2 days to 88.1 days, with a median of 4.4 days. T1/2 of CEA (mean +/- standard deviation) was 11.7 +/- 17.9 days in recurrent patients, whereas it was 6.2 +/- 4.9 days in patients without recurrence (p = 0.0224). The patients' age, gender, size of the tumor, location of the tumor, pre-, and postoperative CEA level, pathologic type of the tumor and Dukes stage had no significance in recurrence. The 1-year, 2-year, and 5-year disease-free survival rates were 95.1%, 81.1%, and 73.8% in patients with postoperative CEA levels less than 5 ng/ml (n = 62), respectively, and 71.4%, 64.8%, and 64.8% in patients with postoperative CEA levels higher than or equal to 5 ng/ml (n = 32), respectively (p = 0.04). Patients were divided into Group S (T1/2 of CEA or = 4.4 days, n = 51). The 1-year, 2-year, and 5-year disease-free survival rates were 95.3%, 85.1%, and 77.7% in Group S, respectively, and 80%, 67.5%, and 64.1% in Group L, respectively (p = 0.0261). In conclusion, the disease-free survival of colorectal cancer patients was prolonged in patients who had a short T1/2 of CEA or a low level of postoperative CEA. In high-risk colorectal cancer patients with an abnormally high level of preoperative CEA, recurrence may be predicted by checking an early postoperative CEA level and/or by a simple calculation of the actual half life of CEA.