A nomogram predicting the recurrence of hepatocellular carcinoma in patients after laparoscopic hepatectomy

Background: Patients with hepatocellular carcinoma (HCC) undergoing surgical resection still have a high 5-year recurrence rate (similar to 60%). With the development of laparoscopic hepatectomy (LH), few studies have compared the efficacy between LH and traditional surgical approach on HCC. The objective of this study was to establish a nomogram to evaluate the risk of recurrence in HCC patients who underwent LH. Methods: The clinical data of 432 patients, pathologically diagnosed with HCC, underwent LH as initial treatment and had surgical margin > 1 cm were collected. The significance of their clinicopathological features to recurrence-free survival (RFS) was assessed, based on which a nomogram was constructed using a training cohort (n = 324) and was internally validated using a temporal validation cohort (n = 108). Results: Hepatitis B surface antigen (hazard ratio [HR], 1.838; P= 0.044), tumor number (HR, 1.774; P= 0.003), tumor thrombus (HR, 2.356; P= 0.003), cancer cell differentiation (HR, 0.745; P= 0.080), and microvascular tumor invasion (HR, 1.673; P =0.007) were found to be independent risk factors for RFS in the training cohort, and were used for constructing the nomogram. The C-index for RFS prediction in the training cohort using the nomogram was 0.786, which was higher than that of the 8th edition of the American Joint Committee on Cancer TNM classification (C-index, 0.698) and the Barcelona Clinic Liver Cancer staging system (C-index, 0.632). A high consistency between the nomogram prediction and actual observation was also demonstrated by a calibration curve. An improved predictive benefit in RFS and higher threshold probability of the nomogram were determined by receiver operating characteristic curve analysis, which was also confirmed in the validation cohort compared to other systems. Conclusions: We constructed and validated a nomogram able to quantify the risk of recurrence after initial LH for HCC patients, which can be clinically implemented in assisting the planification of individual postoperative surveillance protocols.