small numbers of HCC cells may be released into the man research review committee. Informed consent had been obtained from the patients involved. circulation, be it spontaneously or induced by surgical
The results show that albumin mRNA can be demanipulation. Based on their findings, the authors sugtected in central as well as peripheral blood samples gest that, indeed, circulating tumor cells are present collected after, but not before, recipient hepatectomy. in the peripheral circulation as indicated by the PCR A semiquantitive analysis, as expressed by log mRNA technique.
equivalents per milliliter of blood, reveals identical We believe that the outcome of their experiments amounts of albumin expression in blood samples colshould be interpreted more cautiously. As mentioned lected at the indicated time points within the first 24 by Carr in an editorial on this subject in 1994, the hours. Because histological examination of the hepatecassay does not actually measure cancer cells. 2 Thus, tomized livers confirmed the absence of any maligthe mRNA-PCR technique identifies a liver-specific cell nancy, we conclude that positive results of an albumin marker that also may indicate the presence of nontu-mRNA test as such has no predictive value for the presmoral hepatic cells in the circulation. However, because ence of HCC. It may well be that hepatocytes, which the authors only found a positive PCR signal for albuare released into the circulation by surgical manipulamin mRNA in isolated cells from the peripheral blood tion or by reperfusion, are the origin of the albumin of patients with advanced-stage HCC, they speculated mRNA. that it was a result of the presence of malignant cells.
Our findings of positive results of an albumin mRNA The authors did not mention the time points at which assay in patients without a malignancy are in accorblood samples were obtained. The results of our studies dance with the report or Matsumura et al., 3 who using the same technique to detect albumin mRNA showed the presence of albumin mRNA in peripheral within the first 24 hours after liver transplantation blood of normal volunteers. Their results and those of show different results and cast doubt on the value of our study indicate that the consequences of positive this assay as a method to identify the presence of maligassay results for albumin mRNA should be interpreted nant cells in the circulation after liver transplantation.
cautiously in relation to HCC. We have conducted a study in which peripheral and central whole blood samples were taken at regular in-JAN N. M. IJZERMANS 1 tervals (immediately before surgery and 5, 30, 60, and DIRK-JAN BAC 2 120 minutes and 24 hours after recipient hepatectomy) BERT G. M. NIESTERS 3 from five consecutive patients undergoing liver trans-Departments of 1 Surgery, 2 Hepatology, and plantation for benign liver disease. Indications for liver