Figure 1 demonstrates the enrollment pathway of all patients with CRLOM. A total of 1.027 patients with 3256 hepatic nodules (mean size 2.3 cm) were enrolled. The baseline characteristics of all patients are shown in Table 1, which were assigned to SR (n = 464) and MWA groups (n = 563). Except for age, sex, CA- 199, and primary tumor_site, other variables were statistically different between the two groups (all, P < 0.05). To adjust the potential imbalances in the two treatment groups, we performed PSM 1:1, and each group included 393 patients, which decreased the differences between the two groups. All variables were well balanced after PSM, as shown in Supplementary Fig. 2. The study population’s median follow-up duration was 40.2 months (IQR 7.4–62.7 months) in the SR group and 38.9 months (IQR 7.0–61.2 months) in the MWA group, respectively.

Flowchart of patient selection for the current study

After PSM, the cumulative 1-, 3-, 5-, and 8-year PFS rates were 88.2%, 51.5%, 28.4%, and 22.5%, respectively in the SR group, and 94.4%, 61.7%, 36.9%, and 16.0%, respectively in the MWA group, showing a significant statistical difference (Fig. 2A, P = 0.68). The cumulative 1-, 3-, 5-, and 8-year IPFS rates were 84.8%, 47.6%, 24.2%, and 21.0%, respectively in the SR group, and 91.7%, 55.8%, 24.2%, and 8.5%, respectively in the MWA group, showing significant statistical difference (Fig. 2B, P = 0.71). The cumulative 1-, 3-, 5-, and 8-year OS rates were 92.2%, 70.8%, 32.2%, and 14.7%, respectively in the SR group, and 94.2%, 71.0%, 32.2%, and 14.2%, respectively in the MWA group, showing a significant statistical difference (Fig. 2C, P = 0.12). Before PSM, the cumulative 1-, 3-, 5-, and 8-year PFS rates were 88.2%, 51.3%, 28.8%, and 22.5%, respectively in the SR group, and 94.4%, 61.7%, 37.2%, and 16.4%, respectively in the MWA group, showing no significant statistical difference (Fig. 2D, P = 0.53). The cumulative 1-, 3-, 5-, and 8-year IPFS rates were 84.6%, 47.6%, 24.0%, and 21.4%, respectively in the SR group, and 91.4%, 55.3%, 24.5%, and 8.5%, respectively in the MWA group, showing a significant statistical difference (Fig. 2E, P = 0.76). The cumulative 1-, 3-, 5-, and 8-year OS rates were 92.2%, 70.4%, 31.5%, and 14.8%, respectively in the SR group, and 94.5%, 71.7%, 32.2%, and 14.4%, respectively in the MWA group, showing no significant statistical difference (Fig. 2F, P = 0.51).

Survival curves with log-rank test stratified by treatment modalities with or without the PSM adjusted. A PSM-adjusted overall survival (OS). B PSM-adjusted progression-free survival (PFS). C PSM-adjusted intrahepatic progression-free survival probability (IPFS). D Crude OS before PSM. E Crude PFS before PSM. F Crude IPFS before PSM

Table 2 shows the therapeutic parameters between the SR and MWA groups. After PSM, the technique success rate was 89.2% in the SR group and 90.7% in the MWA group. There was no significant statistical difference (P = 0.413). Patients who underwent MWA had shorter postoperative hospitalization (P = 0.012), blood loss (P = 0.033), and lower costs (P = 0.017) than those of patients who underwent SR. The sequential therapeutic rate (56.4%) in the MWA group was significantly higher than that (23.9%) in the SR group (P < 0.001).

The risk factors of survival outcomes were assessed by univariate and multivariate analysis (Table 3). In the univariate analyses, smoking (hazard ratio [HR] 1.28; 95% CI 1.00–1.63; P = 0.048), drinking (HR 1.33; 95% CI 1.03–1.71; P = 0.028), 3–5 intrahepatic nodules (HR 1.67; 95% CI 1.34–2.09; P < 0.001), and a tumor size of 3–5 cm (HR 1.28; 95% CI 1.01–1.63; P = 0.040) were significant factors for poor OS. Multivariate analyses showed that the factors that significantly affected the OS rate were 3–5 intrahepatic nodules (HR 1.65; 95% CI 1.31–2.06; P < 0.001) and SR (HR 1.28; 95% CI 1.11–1.69; P = 0.028). In the univariate analyses, bilobar distribution (HR 1.19; 95% CI 1.00–1.40; P = 0.045), low-moderate pathology (HR 1.43; 95% CI 1.12–1.83; P = 0.028), and 3–5 intrahepatic nodules (HR 1.79; 95% CI 1.52–2.12; P < 0.001) were significant factors for poor PFS. Multivariate analyses showed that low-moderate pathology (HR 1.32; 95% CI 1.03–1.70; P = 0.026) and a tumor size of 3–5 cm (HR 1.74; 95% CI 1.47–2.06; P < 0.001) significantly affected the PFS rate. In the univariate analyses, low-moderate pathology (HR 1.54; 95% CI 1.19–1.99; P = 0.001) and 3–5 intrahepatic nodules (HR 1.90; 95% CI 1.59–2.26; P < 0.001) were significant factors for poor IPFS. Multivariate analyses showed that low-moderate pathology (HR 1.41; 95% CI 1.09–1.83; P = 0.010) and 3–5 intrahepatic nodules (HR 1.83; 95% CI 1.53–2.19; P < 0.001) significantly affected the IPFS rate.

Subgroup analysis based on preoperative clinical data in the two treatment groups are shown in Table 4. It is worth noting that there were no significant differences between the two therapies with regard to PFS and IPFS in all subgroups except CRLOM located on the liver bilobar. In addition, the cumulative OS of patients aged > 65 years, with moderate-low pathological differentiation, tumor diameter < 3 cm, and < 3 nodules in the MWA group were higher significantly than those in the SR group. The forest plots are shown in Fig. 3 stratified by therapeutic schedule (SR vs. MWA) based on subgroup analysis.

Forest plots shown the overall survival (OS), progression-free survival (PFS), intrahepatic progression-free survival (IPFS) stratified by treatment modalities

There were no treatment-related deaths in either treatment group. The comparison of procedure-related complications between the two groups is shown in Table 5. After PSM, for minor complications, 34.4% (135/393) of the patients were found in the SR group, showing no significant difference from 33.6% (132/393) of the patients in the MWA group (P = 0.865). For major complications, 2.8% (11/393) of the patients were found in the SR group, showing no significant difference from 3.1% (12/393) of the patients in the MWA group (P = 0.725).