3461 - Impact of Radiation Therapy on Survival in Hepatocellular Carcinoma with Vascular Tumor Thrombus: A Retrospective Analysis of Systemic Therapy Combinations
Presenter(s)
E. Kohilakis1, K. A. Skalina2, B. Malachowska3, S. Vikash4, B. Fortune5, F. Bteich5, Y. Saenger1, A. Kaubisch6, M. Kinkhabwala7, N. Ohri8, J. Tang2, C. Guha9, and R. Kabarriti8; 1Albert Einstein College of Medicine, Bronx, NY, 2Department of Radiation Oncology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, 3Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY, 4Albert Einstein College of Medicine - Jacobi Medical Center, Bronx, NY, 5Montefiore Medical Center, Bronx, NY, 6Department of Medical Oncology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, 7Department of Surgery, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, 8Montefiore Einstein Comprehensive Cancer Center, Bronx, NY, 9Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY
Purpose/Objective(s):
Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality. Vascular invasion can present in up to 45% of cases at diagnosis and portends a poor prognosis. Tyrosine kinase inhibitors (TKIs) were standard of care systemic therapy until recent studies demonstrated improved outcomes with use of combined immune checkpoint inhibitors (ICIs). RTOG 1112 was also the first large randomized international controlled trial to demonstrate improved outcomes with the addition of radiation therapy (RT) to sorafenib. However, the benefit of adding RT to patients receiving ICIs remains unclear. This study evaluates whether RT improves OS in this high-risk population with tumor thrombus and whether its effect differs between upfront treatment with ICI or TKI.Materials/Methods:
We reviewed the medical records of patients with HCC and tumor thrombus at diagnosis treated between January 2009 and January 2024, excluding those who underwent local therapy only without systemic therapy. Tumor thrombus was characterized using the Vp classification for portal vein involvement and included patients with thrombus in the portal vein, hepatic vein, or IVC. Demographic and clinical data, including liver disease etiology, Child-Pugh score, and treatment regimens, were collected. OS was analyzed using Cox proportional hazards models.Results:
A total of 129 patients met inclusion criteria (mean age: 64.5 years; 79.1% male). HCC etiologies included alcohol (n=45), hepatitis B (n=25), hepatitis C (n=75), and NASH (n=13). 72 patients received ICI first line and 51 received TKI first line. Of the 55 patients who received systemic therapy and underwent RT, 11 received less than 5 fractions and 38 received 5-fractions ranging from 25-50Gy. Median follow-up was 5.9 months (range: 0.3–79.1). Addition of RT to systemic therapy significantly improved OS (p=0.023) for the entire cohort. Median survival for ICI-treated patients was 10.8 months with RT compared to 4.9 months without RT (long-rank p=0.0054). For TKI-treated patients, there was a trend for improved survival with addition of RT, but it did not reach statistical significance, (20.9 vs. 5.5 months, p=0.33). Multivariable Cox proportional hazard model controlling for age, Child-Pugh score (A vs. B/C), systemic therapy (ICI vs. TKI), and tumor thrombus (Vp1-3 vs. Vp4/IVC/hepatic vein) classification showed that receipt of radiation was an independent predictor for improved OS (HR 0.59, p=0.0239).Conclusion:
Addition of RT to systemic therapy was associated with a significant survival benefit in HCC patients with vascular tumor thrombus, particularly among those treated with ICIs. Similar to RTOG 1112, while there was a trend to improved OS with the addition of RT in patients receiving upfront TKIs, it did not reach statistical significance in our cohort. These findings highlight RT’s potential role in improving outcomes of HCC patients with tumor thrombus at diagnosis.