Abstract 103P
Background
This study aimed to assess the combined efficacy of systemic therapy and iodine-125 seed implantation as a local treatment in patients with oligometastatic colorectal cancer (CRC), characterized by ≤3 metastatic organs and ≤5 metastatic lesions, focusing on identifying factors that influence patient outcomes.
Methods
We retrospectively reviewed 40 patients with oligometastatic CRC treated from January 2018 to June 2023 at our institution. Patients were divided into two groups: Group A (n=20), who received systemic therapy in combination with iodine-125 seed implantation, and Group B (n=20), treated with systemic therapy alone. The primary endpoint was progression-free survival (PFS), with overall survival (OS) as a secondary endpoint. Kaplan-Meier curves were used for survival analysis, with the Log-rank test for intergroup comparisons. Cox regression analysis was conducted for both univariate and multivariate analyses.
Results
The median PFS for Group A was extended to 18.2 months (95% CI: 15.4–21.0), significantly longer than the 8.7 months (95% CI: 6.3–11.1) observed for Group B (HR=5.80, 95% CI: 3.85–8.75). The median OS for Group A was also extended, reaching 33.4 months (95% CI: 25.1–41.7), which surpassed the 20.5 months (95% CI: 16.3–24.7) for Group B (HR=1.75, 95% CI: 1.10–2.80). Multivariate analysis identified the presence of liver metastases as a significant risk factor impacting PFS. Key factors influencing OS included the oligometastatic status, the presence of liver metastases, histologic subtype, the use of immune checkpoint inhibitors (ICIs), driver mutations, anti-angiogenic treatments, and the incorporation of iodine-125 seed implantation as a part of local therapy.
Conclusions
In patients with oligometastatic CRC and stable primary lesions, integrating systemic therapy with iodine-125 seed implantation significantly improves both PFS and OS compared to systemic therapy alone. This underscores the importance of iodine-125 seed implantation within the comprehensive treatment strategy, highlighting its crucial role in enhancing patient survival outcomes.
Clinical trial identification
ChiCTR2400081993 (Chinese Clinical Trial Registry).
Legal entity responsible for the study
The authors.
Funding
Regional Science and Technology Support Xinjiang Project (No. 2022E02051), Tianshan Talent Training Program (No. 2023TSYCCX0068).
Disclosure
All authors have declared no conflicts of interest.