Does Primary Colorectal Tumor Site Affect Outcomes with RFA?

Primary left-side colorectal cancer and a tumor size ≤ 3 cm were found to independently predict better oncologic outcomes for patients undergoing radiofrequency ablation (RFA) outcome in colorectal liver metastases.

Researchers undertook the retrospective study to evaluate whether a primary tumor on the right or left side was able to predict RFA outcome in colorectal liver metastases. The study included 102 patients who were treated from January 2007 to December 2013 and were enrolled in the study with propensity score matching method. The patients underwent RFA of metachronous colorectal liver metastases, and the investigators analyzed the recurrence rate and overall survival rate between between the two patients cohorts with primary left-side colorectal cancer or primary right-side colon cancer.

Results indicated that the total recurrence rate in all patients was 59.8%. However, compared with patients in the right-sided cohort, patients in the left-sided colorectal cancer group had lower recurrence rates (49.0 vs 70.6%), and non-local recurrence rates (21.6 vs 41.2%). Regarding 5-year overall survival, patients in the right-sided group had a rate of 14% and those in the left-sided group had a rate of 30%. Differences between the groups also occurred in median overall survival, with 29.4 months for right sided versus 40.3 months for left sided.

Univariate analysis revealed that several factors were significant in predicting overall survival—primary tumor side, the number of liver metastases, tumor size, carcinoembryonic antigen level, differentiation, TNM stage, active chemotherapy and RFA boundary. After those variables were analyzed in a multivariate model, right-sided colorectal cancer and tumor size (> 3 cm) were significant.

The researchers commented that further prospective studies are needed to confirm their findings.

Reference

Gu Y, Huang Z, Gu H, et al. Does the site of the primary affect outcomes when ablating colorectal liver metastases with radiofrequency ablation? Cardiovasc Intervent Radiol. 2018;41(6):912-919.