Utilizing the Conversion Concept Based on Disease Status Following Atezolizumab Plus Bevacizumab Treatment for Hepatocellular Carcinoma.

Background: The introduction of atezolizumab plus bevacizumab (Ate/Bev) has improved hepatocellular carcinoma (HCC) treatment, enabling the concept of "ABC conversion," where curative treatments follow Ate/Bev. However, the optimal post-Ate/Bev treatment strategy remains unclear.

Methods: This study evaluated 149 patients with unresectable HCC treated with Ate/Bev and categorized them into six groups: drug-free, surgery, radiotherapy, transcatheter arterial chemoembolization/hepatic arterial infusion chemotherapy (TACE/HAIC), chemotherapy, and best supportive care (BSC). The surgery, radiotherapy, and TACE/HAIC groups were classified as "local conversion" and further subdivided into two subtypes based on the therapeutic intent: "curative local conversion" and "palliative local conversion."

Results: The 3-year overall survival (OS) rates for patients in the drug-free, surgery, radiotherapy, TACE/HAIC, chemotherapy, and BSC groups were 100.0%, 66.7%, 52.6%, 41.0%, 13.6%, and 10.1%, respectively (p < 0.001). No significant differences were observed between the surgery and TACE/HAIC groups (3-year OS: 66.7% vs. 41.0% and p = 0.441) or between the radiotherapy and TACE/HAIC groups (3-year OS: 52.6% vs. 41.0% and p = 0.838). Patients who underwent local conversion had a significantly better median survival time (28.0 vs. 16.3 months and p < 0.001). The 3-year OS rates for patients who underwent curative and palliative local conversion were 68.6% and 37.0%, respectively. Although curative local conversion demonstrated better prognosis than that noted with palliative local conversion, the difference was not statistically significant (p = 0.155).

Conclusion: Local conversion after Ate/Bev treatment may potentially improve survival rates. Even when curative local conversion is not feasible, palliative local conversion may still offer clinical benefits.