Efficacy of CalliSpheres® microspheres versus conventional transarterial chemoembolization in the treatment of refractory colorectal cancer liver metastasis.

Objective: CalliSpheres® is a microsphere that is already widely used for primary liver cancer treatment; however, its application in colorectal cancer liver metastasis (CRLM) is limited. The current study aimed to investigate the efficacy of CalliSpheres® drug-eluting bead (DEB) transarterial chemoembolization (TACE) therapy versus (vs.) conventional cTACE therapy in treating refractory CRLM (RCRLM) patients.

Methods: Twenty-two RCRLM patients who underwent CalliSpheres® DEB-TACE therapy (n = 11) or cTACE therapy (n = 11) were retrospectively analyzed. Data on clinical response, progression-free survival (PFS) and overall survival (OS) were retrieved.

Results: The objective response rate (36.4% vs. 18.2%, P = 0.338) and disease control rate (81.8% vs. 54.4%, P = 0.170) were both numerically (but not statistically) higher in the DEB-TACE group than in the cTACE group. Meanwhile, PFS was prolonged in the DEB-TACE group compared with the cTACE group [median: 12.0 (95% CI: 5.6-18.4) vs. 4.0 (95% CI: 0.9-7.1) months, P = 0.018]; OS was also longer in the DEB-TACE group compared with the cTACE group [median: 24.0 (95% CI: 18.3-29.7) vs. 14.0 (95% CI: 7.1-20.9) months, P = 0.040]. In addition, after adjustment by multivariate Cox analyses, DEB-TACE was superior to cTACE independently regarding PFS (HR: 0.110, 95% CI: 0.026-0.463, P = 0.003) and OS (HR: 0.126, 95% CI: 0.028-0.559, P = 0.006).

Conclusions: CalliSpheres® DEB-TACE therapy may prolong survival profile than cTACE therapy in RCRLM patients, while further validation is still needed.