ESTRO 2024 - Abstract Book

S2211

Clinical - Upper GI

ESTRO 2024

1 Albert Einstein College of Medicine, Medical Student, Bronx, USA. 2 Montefiore Einstein Comprehensive Cancer Center, Radiation Oncology, Bronx, USA. 3 Montefiore Einstein Comprehensive Cancer Center, Hematology/Oncology, Bronx, USA. 4 Montefiore Medical Center, Surgery, Bronx, USA

Purpose/Objective:

Chronic HCV is a leading cause of hepatocellular carcinoma (HCC), despite the availability of virus prevention methods and early virus treatment. 1 Historically, curative treatment for HCC included surgical treatment or liver transplantation. However, many patients are ineligible for these treatments due to limited liver function, extent of disease, or comorbid medical conditions. 2 Stereotactic body radiation therapy (SBRT) is an emerging modality that can provide high rates of local tumor control and may serve as curative treatment for appropriately selected patients. A large, multi-institutional analysis identified HCV etiology as a possible favorable prognostic factor with respect to local disease control after SBRT for HCC. 3 To validate this finding, we performed a systematic review and meta analysis of published studies reporting local control rates following SBRT for HCC. PubMed searches were utilized to identify published reports describing local control outcomes following SBRT for HCC. Publications that had a sample size of at least 30 patients and detailed the prevalence of HCV infection in the study population were included in the analysis. Patient characteristics, measures of disease burden, treatment details, and outcomes data were tabulated for each study. Kaplan-Meier local control curves were digitized, and a customized script was utilized to extract individual patient data from each study. Using study-level data, weighted linear regressions were utilized to quantify associations between HCV infection rates and local control rates following SBRT. Data from studies with high and low prevalence of HCV were pooled. Kaplan-Meier local control curves were generated for each subgroup, and outcomes between groups were compared using Cox proportional hazards modeling. Material/Methods:

Results:

The original searches yielded 295 publications, 23 of which met all selection criteria. HCV infection rates in individual studies ranged from 2% to 83%. The total sample size was 2,274 patients, and 684 patients (30%) had HCV infection. The 3-year local control rate for all patients was 86%. Weighted linear regression of study-level data revealed an association between HCV prevalence and 3-year local control rate, such that the predicted 3-year local control rate for patients without HCV is 83%, compared to 93% for patients with HCV. Pooled analysis of patient-level data also revealed an association between HCV infection and local control following SBRT. The actuarial 3-year local control rate for the 1,470 patients in studies with low (<1/3) prevalence of HCV was 85% (95% CI: 82% to 86%), compared to 96% (95% CI: 93% to 100%) for the 197 patients in studies with high (>2/3) HCV prevalence (HR=0.21, 95% CI 0.09 to 0.51, p<0.001).