cell'' in circulation 3 in preoperative patients. Moreover, the To detect hepatocellular carcinoma (HCC) cells in the significant elevation of serum AFP protein levels sometimes circulating peripheral blood, we previously designed a lags behind the formation of a considerable recurrent mass.
highly sensitive reverse-transcription polymerase chain
Because of the recent advances in the reverse-transcription reaction (RT-PCR) method targeting a-fetoprotein polymerase chain reaction (RT-PCR) technology, several (AFP) messenger RNA (mRNA). Using this method, we studies have been performed for detecting cancer cells in analyzed peripheral blood of in-and out-patients bearlymph nodes or peripheral blood in the form of specific ing HCC for 2 months consecutively and examined the mRNA, the existence of which means the presence of cells outcome thereafter. All 11 patients with recurrence eiproducing the mRNA. Such a system has been developed for ther in the liver alone or in both the liver and the lung melanoma cells, 4 breast cancer cells, 5 prostate cancer cells, 6 were positive for AFP mRNA. Among 10 recurrence-free and neuroblastoma cells. 7 Kar et al. 8, and Hillaire et al. 10 patients, 2 patients were AFP mRNA-negative and redetected the presence of albumin mRNA in peripheral blood mained recurrence-free during a period of 22 months of patients with HCC. But because a small amount of albumin observed. Four of 8 AFP mRNA-positive, recurrencemessage seems to be transcribed in nucleated blood cells, 3 free patients developed a clinically evident recurrence Matsumura et al. developed a RT-PCR system to detect AFP in the liver after 2 to 16 months. Seven of 8 preoperative mRNA in peripheral blood of HCC-bearing patients in 1994. 3 patients were already positive for AFP mRNA and the However, the serum AFP protein level in their HCC patients remaining negative patient became positive during surwas as high as 62,738 { 7,031 ng/mL, whereas the overall gery. Four of 6 preoperatively positive and still-alive papositive rate was 52%. For the practical usage in therapeutic tients had recurrence in the liver after 2 to 9 months.
decision-making and early detection of recurrence, we con-None of the HCC-negative patients were positive for AFP structed an original, easy, and far more sensitive RT-PCR mRNA. We actually found an AFP protein-positive cell system for detecting AFP mRNA in circulation. 11 With this in peripheral blood obtained from one of the AFP method, only a single high-AFP-producing cell in 1 cc of whole mRNA-positive patients by immunostaining. The presblood was recognizable within 12 hours. 11 In the previous ent results suggest that circulating HCC cells may have study, using this system, we found five of seven HCC patients some relationship with the recurrence of HCC in the to be positive for AFP mRNA in their peripheral blood, liver. (HEPATOLOGY 1997;25:564-568.)
whereas four patients with positive hepatitis virus marker(s) but negative for HCC and a healthy volunteer were negative. Hepatocellular carcinoma (HCC) is one of the most common The five AFP mRNA-positive patients consisted of three malignant tumors. In addition to the underlying chronic hepwith a clinically evident recurrence, one preoperative patient atitis or cirrhosis that limits the successful execution of curawith portal tumor thrombus, and one recurrence-free patient tive liver resection, it is not uncommon that curatively rewho developed a clinically detectable recurrence 3 months sected cases develop a recurrence. Although some long-term after this analysis. The remaining two negative patients were survivors have been reported with the recent advances in made up of one preoperative patient and one recurrence-free additional therapeutic choices, such as percutaneous ethanol patient during a period of 6 months observed. injection into the tumor, intrahepatic arterial infusion of an-As we previously explained, there is no denying the possiticancer agents, transcatheter arterial embolization and so bility of a few AFP-producing virus-infected hepatocytes or on, the overall prognosis of HCC is not yet satisfactory. If we degenerating hepatocytes being present in the AFP mRNAwere able to know when and how recurrence will occur in positive results. This is because there is no definite marker individual cases, early detection and intensive therapy adto discriminate between cancer cells and noncancerous hepajusted for the individual might help prolong the survival of tocytes. But this is an analysis not on the secreted protein, the patient. Although the serum level of a-fetoprotein (AFP), but on the highly vulnerable mRNA inside the cell. Anchor- a well-known oncofetal protein, is often used in screening ing-free, noncancerous hepatocytes cannot possibly live long. HCC, 2 secreted AFP protein does not mean the presence of Moreover, the AFP mRNA-positive rate among our noncancerous patients was zero. Therefore, the present analysis can seem to suggest at least a ''high possibility'' of hematogenous prevalence of HCC. 11 Because this system seemed to work, Abbreviations: HCC, hepatocellular carcinoma; AFP, a-fetoprotein; RT-PCR, reversewe began to detect AFP mRNA in the peripheral blood of transcription polymerase chain reaction; mRNA, messenger RNA; cDNA, complementary successive pre-and postoperative HCC patients without any DNA.
choice to further analyze the relationship between the pres-From the