E219: Combined Radiofrequency Ablation with Liver Resection for Colorectal Cancer Liver Metastasis: A Nationwide Survival Analysis

Liver metastasis is a therapeutic challenge in patients with colorectal cancer. There is a paucity of data on the effect of combined radiofrequency ablation (RFA) and liver resection (LR) on outcomes. The aim of our study is to evaluate the effect of combined RFA and LR on long-term outcomes in patients with colorectal cancer liver metastasis (CRLM).

Methods:

We performed a (2015-2017) retrospective analysis of the Nationwide Readmission Database selecting all adult patients with colorectal cancer with liver metastasis. Extra-hepatic disease patients were excluded. Patients were stratified: RFA+LR vs. LR only. Primary outcomes were hepatic disease recurrence, 6-months mortality and post-operative complications: hepatic failure, hematoma, abscess, and bile duct injury (BDI). Secondary outcomes were 6-months readmission and reasons for readmission. Cox regression analysis was performed comparing disease-free survival (DFS).

Results:

A total of 11,962 patients were identified: 60.2% colon cancer (11.5% ascending, 6.2% transverse, 4.2% descending, 17.8% sigmoid, 20.5% unspecified), and 39.8% rectal cancer (18.7% rectosigmoid, 13.7% rectum, and 7.4% overlapping rectum-anal canal). Mean age was 61±13 years, 43.2% were female, and 16.8% underwent primary tumor resection. A total of 887 received RFA+LR while 11,075 received LR only. Overall LR included: 43.1% right lobe, 30.6% left lobe, 26.3% other and overall RFA included: 49.1% right lobe, 29.2% left lobe, and 21.7% bilobar. Patients who received RFA+LR had a similar rate of disease recurrence (34.5%) compared to the LR group (33.8%) (p=0.679) within 6-months. The rate of 6-months mortality was similar in the RFA+LR group (5.4%) compared to the LR group (5.1%) (p=0.721). Patients who underwent RF+LR had similar rate of post-operative complications hepatic failure (1.5% vs. 2.2%; p=0.129), hematoma (15.9% vs. 18.7%; p=0.133), abscess (2.9% vs. 3.4%; p=0.429), BDI (1% vs. 0%; p=0.843) The overall rate of 6-months readmission was 39.2% with the RFA+LR group having a similar rate of readmission (38.8% vs. 39.2%; p=0.808). The most common reasons for readmission were sepsis, acute kidney injury, and neoplasm related pain. The RFA+LR group had similar median DFS 182 [171-193] days compared to the LR group 171 [165-183] days. (p=0.22) Figure 1.

Conclusions:

The use of RFA as an adjunct to LR in CRLM patients may have an acceptable safety profile and may not be associated with worsening oncological outcomes. RFA is an underutilized but promising modality for CRLM local control.