Clinical Outcomes and Predictors in Patients With Unresectable Colorectal Cancer Liver Metastases Following Salvage Percutaneous Radiofrequency Ablation: A Single Center Preliminary Experience

Abstract

Purpose: The purpose of this study was to investigate the clinical efficacy of salvage percutaneous radiofrequency ablation in patients with unresectable colorectal cancer liver metastases.

Methods: The cohort consisted of 81 patients with 126 colorectal cancer liver metastases who underwent radiofrequency ablation between January 2012 and September 2016. The clinical data and ablation data were retrospectively analyzed. The local tumor progression-free survival, overall survival, and prognostic factors were analyzed using the log-rank test and Cox regression model.

Results: The technique success rate was 99.21%. The primary efficacy rate was 100% at the 1-month follow-up. Minor complications were observed in 2 patients, which recovered within 1 week. The median local tumor progression-free survival time of all patients was 29.8 months. The absence of subsequent chemotherapy was an independent predictor of a shorter local tumor progression-free survival time (P < 0.001, hazard ratio: 2.823, 95% confidence interval: 1.603, 4.972). The median overall survival time was 26.8 months. A lesion size greater than 3 cm (P = 0.011, hazard ratio: 2.112, 95% confidence interval: 1.188, 3.754) and the presence of early local tumor progression (P = 0.011, hazard ratio: 2.352, 95% confidence interval: 1.217, 4.545) were related to a shorter survival time.

Conclusions: Percutaneous radiofrequency ablation is safe in patients with colorectal cancer liver metastases refractory from chemotherapy. Subsequent chemotherapy is important to enhance local control. Small lesions and favorable early responses are related to prolonged overall survival.

Keywords: colorectal cancer liver metastases; local tumor progression; overall survival; predictor; radiofrequency ablation; unresectable.

Figure 1.

Survival curves of LTPFS with/without subsequent chemotherapy. The overall estimated median LTPFS was 29.8 months (95% CI: 14.4, 34.1 months). The estimated median LTPFS in patients who received subsequent chemotherapy was not reach, and that of patients who did not receive subsequent chemotherapy was 8.4 months (95% CI: 6.2, 14.4 months). Multivariate analysis revealed that the absence of subsequent chemotherapy was an independent predictor (P < 0.001, HR: 2.823, 95% CI: 1.603, 4.972). LTPFS = local tumor progression-free survival; CI = confidence interval; HR = hazard ratio.

Figure 2.

Survival curves of OS for patients with and without early LTP. The estimated median OS of patients with LTP at 6 months was 15.5 months (95% CI: 11.4, 22.7 months), and that of patients without LTP at 6-month was 32.5 months (95% CI: 22.7, 38.4 months). Multivariate analysis revealed that the presence of early LTP (LTP at the 6-month follow-up) was an independent predictor after adjusting for potential confounders (P = 0.011, HR: 2.352, 95% CI: 1.217, 4.545). OS = overall survival; LTP = local tumor progression; CI = confidence interval; HR = hazard ratio.

Figure 3.

Survival curves of OS based on lesion size. The estimated median OS of patients with lesion diameters >3 cm was 18.7 months (95% CI: 12.2, 21.3 months), and that of patients ≤3 cm was 32.7 months (95% CI: 25.7, 42.7 months). Multivariate analysis revealed that lesion diameters >3 cm were independent predictors after adjusting for potential confounders (P = 0.011, HR: 2.112, 95% CI: 1.188, 3.754). OS = overall survival; CI = confidence interval; HR = hazard ratio.