CT-guided percutaneous microwave ablation for pulmonary metastases from colorectal cancer: Prognosis analyses based on primary tumor location

Abstract Purpose Microwave ablation (MWA) is becoming an effective therapy for inoperable pulmonary metastases from colorectal cancer (CRC). It is unclear whether the primary tumor location affects survival after MWA. Methods Patients who underwent MWA from 2014 to 2021 were enrolled. The survival outcomes and prognostic factors of primary CRC location were evaluated by Kaplan-Meier and Cox regression analyses. Results A total of 118 patients with 154 pulmonary metastases from CRC were treated in 140 MWA sessions. Rectal cancer had a higher proportion with seventy (59.32%) than colon cancer with forty-eight (40.68%). No differences were observed among age, comorbidities, number, pulmonary lobe, metatasic type, laterality, DFI, or CEA, except for sex (p = 0.001) and maximum diameter (p = 0.026). Pneumothorax was the most frequent complication and occurred in 14 (26.42%) in colon cancer and 31 (35.63%) in rectal cancer (p = 0.425). The median follow-up was 18.53 months (range 1.10-60.63 months). Kaplan-Meier analyses revealed that the DFS and OS in colon and rectal cancer were 25.97 vs 11.90 months (p = 0.405), and 60.63 vs 53.87 months (p = 0.149), respectively. Multivariate analyses showed that only age was 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. Conclusion Primary CRC location has no impact on survival for patients with pulmonary metastases after MWA, while disparate prognostic factor exist between colon and rectal cancer. Pulmonary comorbidity may be a risk factor of survival and should be treated carefully.