PROLIFERATING CELL NUCLEAR ANTIGEN AND GRADE OF MALIGNANCY IN SMALL HEPATOCELLULAR-CARCINOMA - EVALUATION IN US-GUIDED SPECIMENS

Background/Aims: We investigated the value of the proliferating cell n uclear antigen. labeling index ratio (PCNA-LI ratio: PCNA-LI of cancer /PCNA-LI of surrounding non-cancerous liver tissue) to clarify the pro gnosis of the patients bearing small hepatocellular carcinomas (HCC) l ess than 20 mm in, diameter and treated by percutaneous ethanol inject ion therapy (PEIT). Material and Methods: Twenty eight HCC patients wh o had received PEIT were divided into 3 groups. The non-recurrence (NR ) group in which no new lesions were observed for at Least 18 months a fter PEIT (13 patients), the early recurrence group (ER) in. which Les ions recurred within one year (6 patients), and the late recurrence gr oup (LR) in, which lesions recurred more than one year after PEIT (9 p atients). Immunohistochemical staining of PCNA was done using biopsied specimens. Results: The PCNA-LI ratio in 37 well differentiated, 13 m oderately differentiated, 11 poorly differentiated HCC were 1.86 +/- 0 .55, 3.33 +/- 0.51, and 4.75 +/- 0.81 (mean +/- SD), respectively. The ratio in ER group (4.57 +/- 0.57) was significantly higher than, that in LR (2.04 +/- 0.61) and NR group (1.87 +/- 0.62) and the PCNA-LI ra tio tended to correlate with the periods until the development of recu rrent lesions in cases of ER group. Conclusions: These results indicat e the PCNA-LI ratio, in conjunction with the histological grade, is a useful marker for evaluating the grade of malignancy, and for predicti ng the period until recurrence after treatment of small HCC.