OBJECTIVE: To detect the mode of yearly biological cycle of malignant biological behavior ofhepatocellular carcinoma (HCC).METHODS: Twenty-one kinds of CT signs reflecting various degrees of malignant biological behaviorwere determined. A total of 360 patients were collected by random sampling of 30 patients each month.CT signs of each patient were fitted in corresponding group of yearly cyclic data respectively by cosinecurves and analysed in terms of sequence characteristics (cosinor).RESULTS: With a 95% confidence, 10 CT signs showed biological rhythm (P<0.05). The acrophaseof CT features for highly-invasive growth concentrated between -60° and -120° from March to April.For low-invasive growth, however, the CT features were relatively low and concentrated between -180°and -270° from July to September. No acrophase was shown between -120° and -180° from May toJune, and between -270° and -330° from October to November.CONCLUSION: Between CT signs of the highly-invasive and those of low-invasive growth of HCC, asequential difference in biological cycles can be observed.
