CT-guided percutaneous microwave ablation for pulmonary metastases from colorectal cancer: Prognosis analyses based on the origin of the primary tumor.

Abstract

Microwave ablation (MWA) is becoming an effective therapy for inoperable pulmonary metastases from colorectal cancer (CRC). However, it is unclear whether the primary tumor location affects survival after MWA. This study aims to investigate the survival outcomes and prognostic factors of MWA based on different primary origins between colon and rectal cancer. Patients who underwent MWA for pulmonary metastases from 2014 to 2021 are reviewed. Differences in survival outcomes between colon and rectal cancer are analyzed with the Kaplan-Meier method and log-rank tests. The prognostic factors between groups are then evaluated by univariable and multivariable Cox regression analyses. A total of 118 patients with 154 pulmonary metastases from CRC are treated in 140 MWA sessions. Rectal cancer has a higher proportion with seventy (59.32%) than colon cancer with forty-eight (40.68%). The average maximum diameter of pulmonary metastases from rectal cancer (1.09 cm) is greater than that of colon cancer (0.89 cm; p = 0.026). The median follow-up is 18.53 months (range 1.10-60.63 months). The disease-free survival (DFS) and overall survival (OS) in colon and rectal cancer groups are 25.97 vs 11.90 months (p = 0.405), and 60.63 vs 53.87 months (p = 0.149), respectively. Multivariate analyses show that only age is an independent prognostic factor in patients with rectal cancer (HR = 3.70, 95% CI: 1.28-10.72, p = 0.023), while none in colon cancer. Primary CRC location has no impact on survival for patients diagnosed with pulmonary metastases after MWA, while a disparate prognostic factor exists between colon and rectal cancer.