Lock, Michael

PURPOSE External beam radiation therapy (EBRT) has gained delayed acceptance as a recommended first-line treatment modality for patients with hepatocellular carcinoma (HCC), given limited evidence that it improves overall survival (OS). We analyzed individual patient data (IPD) from an international cohort to assess OS among patients with HCC treated with EBRT. METHODS We performed a systematic review of publications that assessed EBRT, met prespecified technical standards for HCC, and reported OS (search date December 15, 2022). Corresponding authors were invited to submit IPD for the study. We performed Kaplan-Meier survival analyses to determine OS and restricted mean survival time (RMST) stratified by Barcelona Clinic Liver Cancer (BCLC) stage and treatment status (ie, treatment-naïve and experienced). We performed random effects Cox proportional hazards modeling to assess clinical characteristics associated with OS. RESULTS Data were provided on 4,913 patients treated with EBRT with a median follow-up time of 5.0 years. The median OS was 6.8 years (95% CI, 5.7 to 8.7) for BCLC-0 and 4.6 years (95% CI, 4.1 to 5.1) for BCLC-A. Among treatment-naïve patients, the median OS was not reached (95% CI, 8.6 to not reached) for BCLC-0 and was 5.4 years (95% CI, 4.5 to 6.7) for BCLC-A. In multivariable models, more advanced BCLC stage, higher tumor burden, worse performance status, and Child-Pugh class B or C were associated with a higher risk of mortality. Ablative radiation dose and more recent year of treatment were associated with a reduced risk of death. CONCLUSION To our knowledge, this study represents the largest multinational cohort of patients with HCC treated with EBRT. OS outcomes with EBRT for very early- and early-stage HCC appear to be comparable with resection, thermal ablation, and other ablative locoregional therapies. These data support the inclusion of EBRT in the BCLC HCC clinical decision-making process.

489 Background: To determine if SBRT followed by sorafenib (SBRT/S) improves overall survival (OS), progression free survival (PFS) and quality of life (QOL) vs. sorafenib alone (S), in patients (pts) with HCC. Methods: Eligible pts had new or recurrent HCC, unsuitable for surgery, ablation or TACE, with Zubrod performance status (PS) 0-2, Child-Pugh (CP) A, BCLC stage B or C, ≤ 5 HCCs, sum of hepatic HCCs ≤ 20 cm, and distant metastases ≤ 3 cm. Pts were randomized 1:1 to S 400 mg BID vs. SBRT (27.5-50 Gy in 5 fractions) followed by S 200 mg BID, increased to 400 mg BID after 28 days. Primary endpoint was OS; reported secondary endpoints - PFS, adverse events (AEs - CTCAEv4), and QOL (improvement in FACT-Hep score by ≥ 5 points from baseline to 6 months). Planned sample size was 292 pts (238 OS events, HR=0.72, 80% power, 1-sided α=0.05). Accrual closed early, due to a change in HCC standard of care. Statistics were amended to report as of 7/1/2022, projecting 155 OS events, with 65% power and the same α. OS and PFS were estimated by Kaplan-Meier and arms compared using log-rank test. Cox proportional hazards models were used to analyze treatment effect. Secondary endpoints were tested with 2-sided α=0.05. Results: Of 193 pts accrued from April 2013 to March 2021 from 23 sites, 177 eligible pts were randomized to S (n=92) vs. SBRT/S (n=85). Median age was 66 yrs (27-84); 41% had Hep. C; 19% had Hep. B or B/C. 82% were BCLC stage C. 74% had macrovascular invasion (MVI), 63% with VP3 or VP4 MVI. 4% had metastases. Median sum of max diameter of HCCs was 8.2 cm for S and 6.7 cm for SBRT/S; 40% had a single HCC. Median follow-up for all and alive pts was 13.2 and 33.7 mo. 22% of S pts received SBRT after discontinuing S. With 153 OS events, median OS was improved from 12.3 mo. (90% CI 10.6, 14.3) with S to 15.8 mo. (90% CI 11.4-19.2) with SBRT/S (HR=0.77, 1-sided p=0.0554). After adjusting for PS, M stage, CP A5 vs. 6, and degree of MVI, OS was statistically significantly improved for SBRT/S (HR=0.72, 95% CI 0.52-0.99, 2-sided Cox p=0.042). Median PFS was improved from 5.5 mo. (95% CI 3.4-6.3) with S to 9.2 months (95% CI 7.5-11.9) with SBRT/S (HR=0.55, 95% CI 0.40-0.75, 2-sided p=0.0001). 8 grade (G) 3+ bleeds were seen: 5 in S arm (1 G3 variceal, 2 G3 upper GI, 1 G3 hepatic, and 1 G4 abdominal) and 3 post SBRT/S (2 G3 upper GI, 1 G3 lower GI). Treatment-related G3+ AEs were not significantly different (S - 42%; SBRT/S - 47%; p=0.52), with 3 G5 AEs (S - 1 hepatic failure, 1 death NOS; SBRT/S - 1 lung infection). 83 (47%) pts consented to QoL. Of 20 S and 17 SBRT/S pts with QoL assessments at baseline and 6 months, 10% on S improved in FACT-Hep score vs 35% on SBRT/S. Conclusions: Compared to S alone, SBRT improved OS & PFS in patients with HCC, with no observed increase in AEs, and a strong suggestion for QOL benefit at 6 months. Supported by U10CA180868 (NRG Onc. Op., U10CA180822 (NRG Onc. SDMC), UG1CA189867 (NCORP), and U24CA180803 (IROC) from the NCI. Clinical trial information: NCT01730937 .