Association between Posttreatment Serum Platelet-to-Lymphocyte Ratio and Distant Metastases in Patients with Hepatocellular Carcinoma Receiving Curative Radiation Therapy

SIMPLE SUMMARY: In unresectable hepatocellular carcinoma (HCC), the use of definitive radiation therapy (RT) as a combined locoregional therapeutic strategy has been increasing. Distant metastasis (DM) is one of the main causes of the declining quality of life and survival rates in the majority of cancer patients, necessitating the clinical research of key DM indicators. On the other hand, various serum biomarkers and indices of immune and inflammatory status have been investigated. This study aimed to investigate whether serum immune and inflammatory parameters can help to predict DM in HCC. In our comprehensive evaluation, the highest value of the posttreatment platelet-to-lymphocyte ratio and the lowest value of the posttreatment prognostic nutritional index were significant independent prognostic indicators of distant control and overall survival rates, respectively. Future research is necessary to confirm our findings. ABSTRACT: Background: We sought to investigate whether serum immune and inflammatory parameters can help to predict distant metastasis (DM) in patients with unresectable hepatocellular carcinoma (HCC) undergoing curative radiation therapy (RT). Methods: A total of 76 RT courses were analyzed. The following variables were included in the analysis: systemic inflammation index, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio (PLR), prognostic nutritional index (PNI), absolute lymphocyte count, lymphocyte-to-monocyte ratio, albumin, albumin-to-alkaline phosphatase ratio, RT-related parameters, and levels of total protein, hemoglobin, α-fetoprotein, and PIVKA-II. Distant control (DC) and overall survival (OS) rates were calculated and compared. Results: The mean age was 61.4 years, and most patients were men (n = 62, 81.6%). The median RT fraction number and fractional doses were 12 (range, 4–30) and 5 (range, 2–12) Gy, respectively. With a median follow-up of 12 (range, 3.1–56.7) months, the 1-year DC and OS rates were 64.4% and 55.2%, respectively. The development of DM significantly deteriorated OS (p = 0.013). In the multivariate analysis, significant independent prognostic indicators for DC and OS rates were the highest posttreatment PLR (≤235.7 vs. >235.7, p = 0.006) and the lowest posttreatment PNI (≤25.4 vs. >25.4, p < 0.001), respectively. Conclusions: Posttreatment serum PLR might be helpfully used as a predictive biomarker of DM in unresectable HCC patients undergoing RT. Future research is necessary to confirm our findings.