Prognostic value of radiological and pathological complete response following immune-based conversion therapy in...

It is unclear whether radiological complete response (rCR) and pathological complete response (pCR) after immune-based conversion therapy are associated with each other and with the prognosis of patients with initially unresectable hepatocellular carcinoma (uHCC).

Data were retrospectively analyzed from 1,262 patients with uHCC who received immune-based conversion therapy at 22 medical centers across China between 2019 and 2023. Survival was compared among patients showing different responses through conventional analysis of all patients, conventional analysis of propensity score-matched subgroups, and landmark analyses at 5 and 7 months after treatment.

Conversion therapy led to tumor downstaging in 343 patients (27.2%) and upstaging in 91 (7.2%) based on modified Response Evaluation Criteria in Solid Tumors (mRECIST) criteria. The 254 patients who achieved rCR showed significantly better overall survival at 3 years than the 1,008 who did not (79.4% vs. 34.0%), as well as significantly longer progression-free survival (hazard ratio [HR] 0.22, 95% confidence interval 0.19-0.26). These survival benefits were confirmed in landmark analyses at 5 and 7 months and in propensity score-matched subgroups. pCR was associated with better overall survival (HR 0.29) and recurrence-free survival (HR 0.40). Among those undergoing hepatectomy after conversion therapy, rCR was strongly associated with higher pCR rates (67.1% vs. 13.8% in non-rCR patients; Φ = 0.55). Multivariate analysis identified the following baseline predictors of rCR: Child-Pugh A grade, α-fetoprotein <400 ng/ml, solitary tumors, no macrovascular invasion, and absence of extrahepatic metastasis. The only preoperative predictor of pCR was rCR (odds ratio 16.65).

Both rCR and pCR may be reliable indicators of prognosis after immune-based conversion therapy in patients with uHCC. These metrics and their predictors may be useful for selecting which patients can benefit from conversion therapy.

It is unclear whether radiological and pathological complete responses after immune-based conversion therapy are associated with each other and with the prognosis of patients with initially unresectable hepatocellular carcinoma. This large-scale retrospective study demonstrates a strong correlation between radiographic and pathologic complete responses, both of which are associated with significantly improved survival outcomes. These findings provide valuable clinical insights, indicating that radiological and pathological complete responses may serve as reliable prognostic indicators following immune-based conversion therapy in this patient population. Furthermore, these response metrics could be used to identify patients most likely to benefit from such therapeutic approaches.