Optimal duration of adjuvant targeted-immunotherapy after successful conversion therapy for initally unresectable HCC with PVTT

The management of initially unresectable hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) has been revolutionized by conversion therapy combining locoregional and systemic modalities. The optimal duration of postoperative adjuvant targeted-immunotherapy is not clear. A retrospective cohort study at four medical centers in China aimed to determine the relationship between adjuvant therapy duration and survival outcomes in this specific patient population. The cohort consisted of 124 patients with initially unresectable HCC and PVTT who achieved successful conversion using combined local and systemic therapy and subsequently underwent R0 resection. Patients were stratified in four groups according to adjuvant targeted-immunotherapy duration: no adjuvant therapy (n=26), short-term therapy (1-3 months; n=28), medium-term therapy (4-6 months; n=25), and extended therapy (≥7 months; n=45). With a median follow-up of 28.3 months, significant differences in both overall survival (OS) and progression-free survival (PFS) were observed among the four groups. Compared to the no-adjuvant group, all treatment durations showed significant survival benefits, with HRs of 0.49 (p=0.004) for OS and 0.44 (p=0.010) for PFS in the short-term therapy group, improving to 0.22 (p<0.001) and 0.15 (pxtagstartz0.001),respectively, in the medium-term group. The medium-term group demonstrated statistical noninferiority compared to the extended-therapy group, both for OS and PFS, establishing a clear efficacy plateau. Treatment-related adverse events were manageable and comparable across the groups. The authors conclude that adjuvant targeted-immunotherapy significantly impact survival outcomes in converted initially unresectable HCC patients with PVTT, with 4-6 months adjuvant therapy being the optimal therapeutic window.