Impact of radiation therapy and alpha-fetoprotein level on survival outcomes for patients with hepatocellular carcinoma: a population-based study.

Abstract

The use of radiation therapy (RT) in hepatocellular carcinoma (HCC) remains a matter for debate. Recently published research indicate that advanced RT techniques may improve survival in patients with HCC. This study aimed to evaluate this hypothesis in a large-scale retrospective cohort. The effect of alpha-fetoprotein (AFP) was taken into account because of its important role in the prognosis of HCC. The Surveillance, Epidemiology, and End Results (SEER) database was queried for adults patients diagnosed 2010-2019 with HCC (≥ 18 years). The study population was divided into four groups: Non-radiation & AFP-positive (reference), Non-radiation & AF-negative, Radiation & AFP-positive, Radiation & AFP-negative. Distant metastasis (DM) was used as a stratification factor. Differences in 5-year overall survival (OS) of the four groups were assessed using the Kaplan-Meier method. Univariate and multivariable Cox proportional hazards model were used to estimate unadjusted and adjusted hazard ratios (HR). A total of 34,656 patients were eligible for this analysis, including 21,084 (60.8%), 8,449 (24.4%), 3,810 (11.0%) and 1,313 (3.8%) in the Non-radiation & AFP-positive, Non-radiation & AF-negative, Radiation & AFP-positive and Radiation & AFP-negative groups, respectively. Median OSs of the four groups were 3, 4, 5 and 11 months in the DM cohort, and 12, 28, 15, and 28 months in the Non-DM cohort. Patients in the Radiation & AFP - group had the best OS and patients in the Non-radiation & AFP + group had the worst OS (adjusted HR [95% confidence interval (CI)]: 0.497 [0.399-0.619] in the DM cohort, and 0.405 [0.372-0.441] in the Non-DM cohort). Radiation & AFP + also showed improved survival compared with the reference group (adjusted HR [95%CI]: 0.725 [0.657-0.801] in the DM cohort, and 0.630 [0.600-0.661] in the Non-DM cohort). This population-based cohort study confirmed a significant improvement in overall survival with radiation therapy in HCC. AFP-negative patients benefit the most from RT. Superior OS of radiation therapy and AFP-negative status persisted even in patients with complex metastasis patterns. Our data suggest that radiation may provide an alternative modality for unresectable HCC.