Changes in Posttreatment Spleen Volume Associated with Immunotherapy Outcomes for Advanced Hepatocellular Carcinoma

We investigated whether spleen volume (SV) changes were associated with treatment outcomes in advanced hepatocellular carcinoma (HCC) patients who received immunotherapy or first-line sorafenib.

Patients with advanced HCC who underwent immunotherapy or first-line sorafenib at our institute were retrospectively analyzed. CT was used to measure SV before and within 3 months of treatment initiation. Tumor assessment followed Response Evaluation Criteria in Solid Tumors version 1.1. The association between SV change and tumor response or progression-free survival (PFS) was analyzed. The inverse probability of treatment weighting (IPTW) was used to adjust for differences in baseline characteristics.

The immunotherapy group comprised 143 patients (124 men, mean age, 59.8 years ± 11.2 [standard deviation]), while the sorafenib group had 57 (47 men, mean age, 59.6 years ± 9.9). SV increased in 108 (75.5%) immunotherapy and 21 (36.8%) sorafenib patients. In the immunotherapy group, patients with increased SV were more likely than those with decreased SV to have a higher disease control rate (76.9% vs 57.1%, p = 0.024) and durable clinical benefit (52.8% vs 25.7%, p = 0.005). It was also associated with extended PFS in the immunotherapy group in both the univariate (p = 0.028) and multivariate (p = 0.014) analysis. By contrast, in the sorafenib group, an increased in SV was not associated with treatment response but was presumably associated with reduced PFS (p = 0.072) in the multivariate analysis. After IPTW adjustment, the increase in SV remained a significant predictor for DCB and PFS in the immunotherapy group.

Most patients exhibited an increase in SV after the initiation of immunotherapy, which may be used to predict response and prognosis. However, this association was not observed in patients who received sorafenib.