Abstract 173P
Background
Evidence regarding the optimal treatment for pulmonary oligometastases from colorectal cancer (CRC) remains inconclusive. Given the lack of prospective comparative data, we aimed to compare the effectiveness of surgery versus stereotactic body radiotherapy (SBRT) as the initial treatment approach for CRC pulmonary oligometastases.
Methods
We retrospectively reviewed 335 consecutive patients who initially received surgery or SBRT for CRC pulmonary metastases from 2011 to 2022, and a total of 251 patients (173 surgery and 78 SBRT) were ultimately included. Freedom from local progression (FFLP), progression-free survival (PFS), and overall survival (OS) were compared by using the stabilized inverse probability of treatment weighting (sIPTW) analysis. Additionally, patterns of local progression and subsequent treatments were analyzed.
Results
Median follow-up was 61.6 months for surgery and 54.4 months for SBRT. After sIPTW adjustment, significant differences emerged in both FFLP and PFS between surgery and SBRT (FFLP: HR = 0.50, 95% CI, 0.31-0.79; PFS: HR = 0.56, 95% CI, 0.36-0.87). The 1-, 3-, and 5-year FFLP rates were 86.2%, 58.6%, and 54.8% after surgery, and 65.0%, 34.6%, and 31.3% after SBRT, respectively (P = 0.006). The 1-, 3- and 5-year PFS rates were 77.2%, 49.4%, and 45.2% after surgery, and 55.7%, 28.8%, and 26.1% after SBRT, respectively (P = 0.013). However, OS was not significantly affected by treatment approach (HR = 0.93, 95% CI, 0.49-1.76). The 1-, 3-, and 5-year OS rates were 96.8%, 85.9%, and 73.1% after surgery, and 96.7%, 78.9%, and 68.7% after SBRT, respectively (P = 0.849). Significant disparities in local progression patterns were identified (P = 0.006). Recurrence at the treated site was more prevalent after SBRT versus surgery (33.3% vs. 16.9%), whereas new intrathoracic tumors occurred more frequent after surgery versus SBRT (71.8% vs. 43.1%). Both groups chose re-irradiation as the primary salvage local treatment.
Conclusions
Notwithstanding significant differences in FFLP and PFS between surgery and SBRT, the long-term survival in patients with CRC pulmonary oligometastases does not depend on the initial choice of local treatment approach.
Legal entity responsible for the study
The authors.
Funding
National Natural Science Foundation of China (No. 82373082), Beijing Natural Science Foundation (No. L222020), Beijing Municipal Administration of Hospital's Ascent Plan (No. DFL20191101).
Disclosure
All authors have declared no conflicts of interest.