Clinical study on preoperative radiotherapy before hepatectomy for reducing postoperative recurrence risk in patients with central hepatocellular carcinoma / 肿瘤研究与临床

ABSTRACT

Objective:To investigate the effect of preoperative radiotherapy on postoperative recurrence in central hepatocellular carcinoma patients treated by hepatectomy.Methods:A retrospective cohort study was conducted. Clinicopathological data of 142 patients with central hepatocellular carcinoma who underwent surgical treatment at the Cancer Hospital of Chinese Academy of Medical Sciences and Peking Union Medical College from January 2016 to January 2019 were retrospectively collected. According to whether they received preoperative radiotherapy or not, the patients were divided into preoperative radiotherapy group (30 cases) and surgery-only group (112 cases). The main observation indexes were recurrence-free survival (RFS), intraoperative bleeding amount, operation time and the occurrence of postoperative complications. Kaplan-Meier method was used for survival analysis, and log-rank test was used for intergroup comparisons; the differences between the two groups for each factor were evaluated by standardized mean difference (SMD); Cox proportional hazards model was used to analyze the influencing factors of RFS in central hepatocellular carcinoma patients with hepatectomy. Propensity score matching (PSM), regression model-adjusted propensity score (CAPS) and inverse probability of treatment weighting (IPTW) methods were used to investigate the relationship between exposure factors and confounding variables and RFS. Sensitivity analysis was performed using E-value to assess the potential impact of unmeasured confounders on outcomes.Results:Men comprised 96.7% (29/30) and 87.5% (98/112) of the preoperative radiotherapy and surgery-only groups, with ages of (55±10) years old and (54±12) years old, respectively. Before matching by the PSM method, there were differences in gender, proportion of patients with hepatitis C, alanine aminotransferase, serum albumin, alpha-fetoprotein, satellite nodules by postoperative pathology, and number of tumors between the two groups (all SMD > 0.1). A total of 26 pairs of patients were successfully matched, and there was no difference in baseline characteristics between the preoperative radiotherapy group and the surgery-only group after matching (all SMD < 0.1). Univariate Cox regression analysis showed that preoperative radiotherapy, number of tumors, maximum diameter of tumor, and satellite nodules by postoperative pathology were the influencing factors of RFS (all P < 0.05); multivariate Cox regression analysis showed that preoperative radiotherapy was an independent protective factor of RFS in central hepatocellular carcinoma patients with hepatectomy ( HR = 0.55, 95% CI: 0.31-0.97, P = 0.038), and maximum diameter of tumor ( HR = 1.08, 95% CI: 1.02-1.15, P = 0.005) and satellite nodules by postoperative pathology ( HR = 1.97, 95% CI: 1.21-3.19, P = 0.006) were independent risk factors of RFS. Preoperative radiotherapy was associated with superior RFS in patients with central hepatocellular carcinoma (PSM, HR = 0.41, 95% CI: 0.20-0.86, P = 0.018; CAPS, HR = 0.42, 95% CI: 0.20-0.87, P = 0.019; IPTW, HR = 0.41, 95% CI: 0.22-0.76, P = 0.005). Before matching, the 1-, 3-, and 5-year postoperative RFS rates in the preoperative radiotherapy group were 77%, 56% and 45%, respectively, and the surgery-only group were 48%, 32% and 28%, respectively. RFS in the preoperative radiotherapy group was superior to that in the surgery-only group before and after matching ( χ2 = 5.65, P = 0.017; χ2 = 6.00, P = 0.014). The E-value for unmeasured confounders altering the conclusions was 2.39, suggesting reliable and stable results. After matching, intraoperative bleeding [ M ( Q1, Q3)] for patients in the preoperative radiotherapy group and the surgery-only group was 300 ml (125 ml, 600 ml) and 400 ml (200 ml, 600 ml), respectively ( U = 0.51, P = 0.611), and the proportions of patients with the operation time >180 min were 92.3% (24/26) and 84.6% (22/ 26), respectively ( χ2 = 0.75, P = 0.385), and the rates of mild postoperative complications were 100.0% (26/26) and 92.3% (24/26), respectively ( χ2 = 2.08, P = 0.149), the differences were not statistically significant. Conclusions:Preoperative radiotherapy for hepatectomy in patients with central hepatocellular carcinoma is safe and effective, and has the advantage of reducing postoperative recurrence.