2875 - Radiation Therapy for Oligometastatic Lymph Node Progression in Hepatocellular Carcinoma: Survival and Failure Outcomes

Purpose/Objective(s):

Lymph node (LN) metastasis represents the most common site of extrahepatic spread in hepatocellular carcinoma (HCC). Despite its frequency, optimal management strategies for oligometastatic LN progression remain incompletely defined. We thought to evaluate clinical outcomes following ablative radiation therapy (RT) for LN recurrence.

Materials/Methods:

We performed a retrospective analysis of patients with HCC treated with RT to LN recurrence. Overall survival (OS) was defined from RT initiation to death or last follow-up. Progression-free survival (PFS) was defined from RT to radiographic disease progression. Survival outcomes were estimated using the Kaplan–Meier method and compared using log-rank tests. Local control (LC) was defined as absence of progression within the irradiated LN volume. Multifactorial etiology was defined as the presence of more than one documented HCC risk factor, including viral, metabolic, or alcohol-associated liver disease. Treatment groups were categorized as RT alone, RT with concurrent immunotherapy (RT+IO), or RT with concurrent systemic therapy excluding immunotherapy (RT+systemic).

Results:

Fifty-nine patients were identified from 2014-2025 (median age was 64 years, 81.4% male). The cohort was 39% of White and 28.8% of Hispanic/Latino patients. The most common etiologies of liver disease were hepatitis C (33.9%), multifactorial (viral, metabolic, and/or alcohol-associated risk factors; 25.4%) and hepatitis B (15.3%). At diagnosis, BCLC stages A, B, and C were observed in 39.0%, 20.3%, and 32.2% of patients, respectively. Most patients had preserved functional status at recurrence (ECOG 0; 78%); 10.2% of patients had undergone prior liver transplant. Radiation targets included combined liver and lymph node treatment in 28 patients (47.5%), single lymph node treatment in 23 (39.0%), and multiple lymph node treatment in 8 (13.6%). Thirty-five patients (59.3%) received RT alone, 18 (30.5%) received RT+IO, and 6 (10.2%) received RT+systemic. Stereotactic body RT (SBRT) was the predominant technique (76.3%), with a median dose of 45 Gy delivered in 5 fractions.

With a median follow-up of 55.1 months, median OS and PFS were 15.4 and 3.9 months, respectively. One- and two-year OS rates were 50.8% and 38.4%, while corresponding PFS rates were 28.9% and 21.7%. RT alone was associated with improved OS compared with RT+IO (35.2 vs 10.5 months, p=0.030) and RT+systemic (35.2 vs 3.6 months, p<0.001). No statistically significant differences in PFS were observed between RT alone and RT+IO. While 48 patients experienced a PFS event, LC rates were high at 74.6%.

Conclusion:

In this cohort of patients with HCC treated with RT for LN recurrence, local control was favorable despite short PFS. These findings support RT as an effective modality for regional disease control in this population, particularly for post-transplant patients or those who cannot receive IO.