Baseline characteristics
This study eventually included a total of 241 patients. The optimal cut-off value of PDWLR as determined by the ROC curve was 9.66. Subsequently, all 241 patients were stratified into low PDWLR (≤ 9.66, n= 119) and high PDWLR (> 9.66, n= 122) groups. While there were no statistical differences observed in most of the relevant variables amongst the baseline characteristics between the two groups (all P > 0.05), patients with high PDWLR exhibited poorer liver function and higher incidences of cirrhosis (84.4% vs. 62.2%, P < 0.001), as well as a greater likelihood of experiencing intraoperative bleeding (41.0% vs. 27.7%, P < 0.001) (Table 1).
Survival outcomes
After a median follow-up of 54.2 months, 140 (58%) patients experienced tumor recurrence and 101 (42%) patients died. For the entire cohort, the 1-, 3-, and 5-year OS were 87%, 67%, and 57%, while the 1-, 3-, and 5-year RFS were 67%, 46%, and 35%, respectively. The low PDWLR group showed a better 1-, 3-, and 5-year OS of 90%, 74%, and 66%, respectively, compared to the high PDWLR group which had an OS of 83%, 60%, and 48%, respectively (Figure 1A). Similarly, the low PDWLR group had a better 1-, 3-, and 5-year RFS of 76%, 54%, and 41%, respectively, compared to the high PDWLR group which had an RFS of 58%, 39%, and 29%, respectively (Figure 1B). The log-rank test using K-M curves indicated that high PDWLR played a negative effect on both OS and RFS for patients with HCC after hepatectomy (P = 0.006 and P = 0.002, respectively).
Independent-risk factors of overall survival and recurrence-free survival
Variables with a P-value < 0.1 in the univariate Cox regression analysis were entered into the forward stepwise multivariate Cox proportional hazard regression analysis, and the results are presented in Table 2 and Table 3. The findings suggested that high PDWLR was an independent risk factor for both OS (HR:1.549, 95%CI 1.018-2.357, P = 0.041) and RFS (HR:1.655, 95%CI:1.160-2.360, P = 0.005). To avoid collinearity, PLR, PDW, and PLT were analyzed separately with other variables, and the results indicated that PLR was also an independent risk factor for both OS (HR: 1.144, 95%CI: 1.009-1.513, P = 0.042) and RFS (HR: 1.109, 95%CI: 1.025-1.458, P = 0.027). However, the PDW and PLT were not found to be significant independent risk factors for OS (HR: 1.005, 95%CI: 0.876-1.305, P = 0.125; HR: 1.309, 95%CI: 0.841-1.357, P = 0.307, respectively) or RFS (HR: 1.105, 95%CI: 0.894-1.346, P = 0.061; HR: 1.108, 95%CI: 0.611-1.284, P = 0.619, respectively).
Performance to predict the prognosis
The area under the time-dependent ROC curve was calculated to determine which indicator was better at predicting survival. Initially, we evaluated the model's ability to predict overall survival at five years, as shown in Figure 2A. The AUC value for PDWLR was 0.651 (95% CI 0.592-0.704), indicating that it had a higher diagnostic capacity than PLR (AUC: 0.602, 95% CI 0.537-0.647), PDW (AUC: 0.557, 95% CI 0.529-0.611), and PLT (AUC: 0.536, 95% CI 0.514-0.576) (all P < 0.05). Therefore, PDWLR had the highest ability to predict overall survival compared to the other indicators at five years. Furthermore, we calculated the estimated AUC with a 95% confidence interval at different time points using time-dependent ROC curves (Figure 2B). The results showed that the AUC of PDWLR was stable, with a median AUC of 0.648 (range 0.605-0.691).