This retrospective analysis assessed whether microsphere size affects efficacy and safety when using irinotecan-loaded drug-eluting beads (DEBIRI) during transarterial chemoembolization (TACE) as second-line therapy for patients with colorectal cancer liver metastases (CRC-LM). The aim was to compare short- and long-term tumor response, survival outcomes, and adverse events between 100–300 μm (small-size) and 300–500 μm (large-size) microspheres.
Patients treated with DEBIRI-TACE at Yantai Yuhuangding Hospital between November 2020 and November 2022 were retrospectively reviewed. The initial cohort comprised 65 CRC-LM patients who had progressed after first-line systemic therapy. Five patients were excluded because of loss to follow-up, leaving 60 patients for analysis. Thirty patients received 100–300 μm irinotecan-loaded beads (small-size group) and thirty received 300–500 μm beads (large-size group).
The study compared short- and long-term efficacy measures and adverse reaction rates between the two bead-size groups. Univariate and multivariate Cox regression analyses were performed to identify independent factors associated with progression-free survival (PFS) and overall survival (OS).
Tumor response was reported as objective response rate (ORR) and disease control rate (DCR) at 1, 3, 6, and 12 months after TACE.
Small-size group (100–300 μm): ORR at 1, 3, 6, 12 months were 56.7%, 50.0%, 40.0%, and 30.0% respectively. Corresponding DCRs were 93.3%, 90.0%, 80.0%, and 66.7%.
Large-size group (300–500 μm): ORR at 1, 3, 6, 12 months were 36.7%, 26.7%, 23.3%, and 16.7% respectively. DCRs were 86.7%, 76.7%, 76.7%, and 60.0%.
Although absolute ORR and DCR values favored the small-size group at each time point, the differences between groups did not reach statistical significance (all P > 0.05).
Median survival outcomes were reported for each group:
Median PFS: 15.0 months in the small-size group versus 13.8 months in the large-size group.
Median OS: 26.0 months in the small-size group versus 21.5 months in the large-size group.
No statistically significant differences were observed between the two bead-size groups for PFS or OS (all P > 0.05).
Overall incidence of adverse reactions was 76.6% in the small-size group and 70.0% in the large-size group (P = 0.559). Incidence of severe adverse events (grade ≥3) was 23.3% for the small-size group and 16.7% for the large-size group (P = 0.519). There were no treatment-related deaths reported in either group. The abstract does not provide a breakdown of specific adverse event types or timing beyond these rates.
Both bead sizes demonstrated acceptable safety profiles in this cohort, with no statistically significant difference in overall or severe adverse event rates.
Multivariate Cox regression analysis identified three independent predictors for both progression-free survival and overall survival: Child-Pugh grade, Eastern Cooperative Oncology Group (ECOG) performance status, and the number of liver metastases. The abstract does not provide hazard ratios, confidence intervals, or detailed results for the univariate analyses.
In this retrospective single-center cohort of CRC-LM patients receiving second-line DEBIRI-TACE, there was no statistically significant difference in tumor response rates (ORR, DCR), survival outcomes (PFS, OS), or overall safety between 100–300 μm and 300–500 μm irinotecan-loaded microspheres. Both bead sizes were associated with measurable tumor control and acceptable adverse event profiles.
Independent clinical factors—Child-Pugh grade, ECOG score, and number of hepatic metastases—were associated with PFS and OS, suggesting patient selection and baseline liver function/performance status may be more influential for outcomes than microsphere size in this dataset.
Limitations: The abstract indicates a retrospective design and reports the sample size and follow-up exclusions; however, details commonly sought by clinicians and researchers—such as hazard ratios and confidence intervals from Cox models, specific adverse event types and timing, baseline characteristics comparison between groups, embolization protocols, irinotecan dosing, imaging criteria used for response assessment, and duration of follow-up—were not reported in the abstract. The full text would be required to evaluate these methodological and reporting details.
Overall, the study's findings suggest clinicians may select either 100–300 μm or 300–500 μm irinotecan-loaded beads for DEBIRI-TACE in second-line management of CRC-LM without clear differences in efficacy or safety, though patient-level factors remain important determinants of outcome. The article is published in Chinese; readers should consult the full text for comprehensive methods and data.