Background: The purpose of the study was to compare the abilities of the JIS and modified JIS (m-JIS) scores to predict survival after hepatectomy for hepatocellular carcinoma (HCC).
Methods: Data for patients who underwent hepatectomy for HCC at Hiroshima University Hospital between 1986 and 2006 were included. The overall survival and disease-free survival were calculated by the Kaplan-Meier method, and differences between groups were tested by the log-rank test. The statistics of the Akaike information criterion (AIC) were used to show the more appropriate model.
Results: A total of 626 patients were included (male/female, 468/158; mean age, 63.4+/-9.6 years; Child-Pugh class A/B, 524/102; liver damage grade A/B/C, 356/261/9). Mean survival and disease-free survival were 8.04+/-0.39 and 4.69+/-0.32 years, respectively. There was a significant difference in the overall survival rate between JIS scores 1 and 2, and 2 and 3 (P<0.05), but not between scores 0 and 1, or 3 and 4 (P>0.05). Except between m-JIS scores 0 and 1, there was excellent discriminatory ability in overall survival rate between other consecutive groups. Concerning disease-free survival, a significant difference was found only between JIS scores 1 and 2. However, the disease-free survival rate could be well differentiated between m-JIS scores 1 and 2, and 3 and 4. The m-JIS score had a higher discriminatory ability, indicated by a linear trend analysis, and a higher homogeneity likelihood ratio, and lower AIC statistics, than the original JIS score in predicting both overall and disease-free survival.
Conclusions: The modified-JIS scoring system using liver damage grade is better than the original JIS scoring system in predicting survival after hepatectomy for HCC in Japan.