Number of Tumors Stratifies the Therapeutic Response to Atezolizumab plus Bevacizumab Therapy in Barcelona Clinic Liver Cancer Stage B Unresectable Hepatocellular Carcinoma: A Multicenter Analysis.

[INTRODUCTION] Atezolizumab plus bevacizumab (ATZ + BV) is used for the treatment of Barcelona Clinic Liver Cancer (BCLC) stage B unresectable hepatocellular carcinoma (u-HCC) patients. However, the efficacy of ATZ + BV in various BCLC stage B conditions, especially the up-to-seven criteria in/out, has not been fully investigated.

[METHODS] We enrolled 83 BCLC stage B u-HCC patients with Child-Pugh class A who were treated with ATZ + BV as the first-line systemic chemotherapy in the study. All patients were evaluated for initial responses by dynamic computed tomography or magnetic resonance imaging after the initiation of ATZ + BV, and therapeutic efficacy was assessed.

[RESULTS] When stratified by up-to-seven criteria, progression-free survival (PFS) was significantly prolonged in patients with up-to-seven in (in vs. out: median 21.0 vs. 8.2 months, p = 0.006), and the Cox proportional hazard model showed that up-to-seven out/in was the significant factor contributing to PFS (out vs. in: HR 2.58, p = 0.007). We next evaluated PFS stratified by the maximum intrahepatic tumor diameter and number of intrahepatic tumors, which constitute the up-to-seven criteria. The number of tumors was a significant factor contributing to PFS (>7 vs. ≤7: HR 1.75, p = 0.040), but maximum tumor size was not (>5 cm vs. ≤5 cm: HR 1.19, p = 0.588).

[CONCLUSION] In BCLC stage B u-HCC patients treated with ATZ + BV, a high number of intrahepatic tumors were associated with poor PFS. Therefore, it may be better to consider additional treatment strategies in these patients.