We assessed whether current therapies could lead to hematogenous dissemination of malignant hepatocytes in hepatocellular carcinoma (HCC) patients using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) for alpha-fetoprotein (afp) and albumin (alb) mRNAs. We analyzed 137 peripheral blood samples before, during and after treatment from 84 patients under radiotherapy, surgical resection or chemotherapy. As compared to the upper limit for 53 healthy/non-HCC controls, alb- mRNA levels increased 2-10-fold in 6% of patients pre-treatment and 2-2.6x10(4)-fold in 32% post-treatment. Levels of afp- mRNA increased 3-210-fold in 17% pre-treatment and 4-5x10(5)-fold in 30% post-treatment. During a longitudinal follow-up of eight patients under radiotherapy or radiotherapy/resection, alb-mRNA levels were normal before treatment, whereas afp-mRNA levels increased 10-fold in two patients. During treatment, alb-mRNA and afp-mRNA levels increased 2-61-fold in three patients and 2.5-5-fold in two patients, respectively. After treatment, alb-mRNA levels declined to normal in all three patients within 3.5 months, but afp-mRNA levels increased 127-5x10(5)-fold in three patients within 5 months. We show evidence that HCC cells disseminating mostly post-treatment may be the 'seed' of recurrence/metastasis. In conjunction with the serum alpha-fetoprotein test, sequential afp-mRNA quantification could predict clinical metastasis/recurrence in 56% of patients during a 4-year follow-up.