A Nomogram Predicting Pulmonary Metastasis Of Hepatocellular Carcinoma Following Partial Hepatectomy

Part I The Independent risk factors of pulmonary metastasis of hepatocellularcarcinoma following partial hepatectomy by competing risk regressionObjective:Hepatocellular carcinoma (HCC) is the fifth most common malignant tumor in the world.Partial hepatectomy remains the mainstay of treatment offering a hope of long-termsurvival for HCC patients. However, prognosis of HCC patients following partialhepatectomy is not always favorable due to a significant chance of intrahepatic recurrenceand distant metastasis, and pulmonary metastasis (PM) represents nearly50%of EHM.Our study aimed to find independent risk factors of pulmonary metastasis of hepatocellularcarcinoma following partial hepatectomy.Patients and Methods:We prospectively collected the data of a cohort of912consecutive patients who underwentpartial hepatectomy between July2002and April2010at4th Department of HepaticSurgery of the Eastern Hepatobiliary Surgery Hospital (EHBH). Finally,838HCC patientswho met the inclusion criteria were analyzed for PM. In our study, these patients weredivided into a development population and a validation population randomly:628(74%)patients were served as a development population to develop a nomogram to predict PM,other remaining210(26%) HCC patients were used for validation of the model.Competing risk regression was done by Stata12to find the independent risk factors of PM.Results:The overall survival rates at1,3and5year were91.0%,61.2%,41.7%. The overallrecurrence rates at1,3and5year were43.7%,63.9%,67%. Postoperative PMs weredetected in106and45patients in the development population and validation populationrespectively, and the PM occurrence rates at1,3,5year were8.7%,15.6%,17.1%in thedevelopment population and10.1%,19.3%,20.6%in the validation population. MVI,serum alpha-fetoprotein, tumor size, number, capsule, and intratumoral CD34stainingwere independent risk factors of PMby competing risk regression.Conclusion:MVI, serum alpha-fetoprotein, tumor size, number, capsule, and intratumoral CD34staining were independent risk factors of PM. Part II The establishment of the nomogram predicting pulmonary metastasis ofhepatocellular carcinoma following partial hepatectomyObjective:PM patients of HCC were treated and had a better prognosis owing to the advance oftechnology. So, it is important to identify the PM patients as early as possible. Our studyaimed to constructing a nomogram which incorporate the independent risk factors of PM inPart I and validating the predicting accuracy of the model.Patients and Methods:A nomogram for predicting the probability of postoperative3-year PM was constructedusing R software. Concordance index (C-index) was calculated to evaluate thediscriminatory power of the nomogram and calibration curve was done in the developmentpopulation, validation population and patients within Milan Criteria.Results:The nomogram predicted postoperative PM with a C-index of0.75,0.82and0.78in thedevelopment population, validation population and patients within Milan Criteriarespectively, the nomogram was well calibrated because of no significant differencebetween the predicted and the observed probabilities of postoperative PM.Conclusion:The proposed nomogram predicts optimally the3-year postoperative PM in HCC patientsfollowing partial hepatectomy.