Background. The specific organ microenvironment can promote the colonization of tumor cells. However, lack of research shed light on the liver microenvironment in synchronous liver metastasis in patients with gastric cancer (synGCLM). With the epidemic of HBV infection in China, we aim to explore the influence of hepatitis B surface antigen (HBsAg) on the risk of synGCLM.
Methods. It was a cross-sectional study that enrolled 858 cases of newly diagnosed GC. The inclusion criteria were as follows: 1) Newly diagnosis GC by pathological reports of gastroscopic biopsy or surgical specimen; 2) No surgery, chemotherapy or other treatments were given in other hospitals before admission; 3) SynGCLM confirmed by biopsy or imaging evaluation reported by two senior radiologists, and complete imaging examination to detect other distant organ metastases; 4) Complete medical records including demographic information, tumor characteristics, HBV serologic assay and other clinical factors. HBsAg-positive was defined as the detection of serum HBsAg more than 10 IU/mL. The prevalence of synGCLM was compared between patients with HBsAg (HBsAg+) and those without HBsAg (HBsAg-). The risk factors for synGCLM were analyzed by univariate and multivariate logistic regression analyses. Especially in the HBsAg+ GC patients, aspartate aminotransferase to platelet ratio index (APRI), liver fibrosis-4 index (FIB-4) levels and hepatitis B e antigen (HBeAg) status were further analyzed.
Results. The prevalence of synGCLM of the HBsAg+ group was 16.7%, higher compared to 7.0% of the HBsAg- group, which was of statistical significance (p = 0.014). Multivariate logistic regression analysis demonstrated that HBsAg (OR = 3.359, p = 0.008), the elevated level of carcinoembryonic antigen (CEA) (OR = 3.775, p < 0.001), alpha-fetoprotein (AFP) (OR = 6.204, p < 0.001), γ-glutamyltransferase (GGT) (OR = 5.081, p < 0.001), alkaline phosphatase (ALP) (OR = 3.968, p = 0.002) and age (OR = 1.028, p = 0.033) were risk factors for synGCLM. Among the HBsAg+ patients, both ARPI and FIB-4 were statistically higher in the patients with synGCLM (synGCLM+) compared to those without synGCLM (synGCLM-) (ARPI: p = 0.045; FIB-4: p = 0.047); HBeAg positivity was detected in 20.0% of synGCLM+ patients compared to 6.0% of synGCLM- patients, but the difference was of no significance (p = 0.190).
Conclusions. HBV infection is a risk factor for synGCLM whereas elevated ARPI and FIB-4 may be pro-metastatic especially among the HBsAg+ GC patients. Age, preoperative CEA, AFP, GGT and ALP levels are associated with increased risk of synGCLM.