Active Chronic Hepatitis B increases the risk of Colorectal Liver Metastasis - A retrospective cross-sectional study

Association of Chronic Hepatitis B With Colorectal Cancer and Its Dual Impact on Colorectal Liver Metastasis: A Narrative Review

Viral hepatitis B is infamous for being contracted in young adulthood and adolescence, as high-risk behaviors like unprotected sexual intercourse and intravenous drug abuse are common. Most infections caused by the hepatitis B virus (HBV) are cleared without any long-term sequelae, but some may persist and cause chronic hepatitis B (CHB). This chronicity may produce a state of prolonged inflammation and significantly increase the risk of developing colorectal adenomas (CRA) and colorectal carcinomas (CRC). The aim of this review is to deep-dive into the mechanisms by which CHB may predispose a patient to develop CRA and, more grimly, CRC. It also focuses on studying the influence of CHB on colorectal cancer liver metastases (CRLM). We conducted a comprehensive literature search using databases like PubMed and Google Scholar, focusing on studies that investigate the role of HBV in colorectal carcinogenesis and CRLM rates in patients suffering from CHB. Chronic inflammation, viral protein interactions with tumor suppressor genes, alteration of cellular pathways such as wingless-related integration site (Wnt) signaling, and extrahepatic accumulation of hepatitis B surface antigen (HBsAg) were the key mechanisms identified. Quite peculiarly, CHB, which is thought to increase the risk for CRA, seemed to protect against CRLM probably due to its sclerosing effect on the liver parenchyma and due to certain immune-mediated mechanisms that suppress tumor growth. Nonetheless, high viral count or the presence of hepatitis B envelope antigen (HBeAg) was found to increase the risk for CRLM, potentially due to increased angiogenesis in the liver. These findings provide convincing evidence that enhanced colonoscopic screening and stronger management protocols for patients suffering from it have the potential to reduce the risk of developing CRC and CRLM.

Association between Hepatitis B virus infection and liver metastasis in colorectal cancer

The association between Hepatitis B virus (HBV) infection and colorectal liver metastases (CRLM) remains ambiguous in current population-based evidence. To clarify this, we present a retrospective analysis of 5871 colorectal cancer (CRC) patients. Propensity score matching (PSM) was applied to harmonize age and sex disparities within HBV+ (n = 1696) and HBV- (n = 4175) groups and further within HBV+ subgroups of chronic (CHB, n = 474) and occult (OHB, n = 1222) infections. Our initial results indicated a significant association between HBV infection and synchronous colorectal liver metastasis (SYN-CRLM); however, this association dissipated after PSM was employed to adjust for confounding variables. No significant association was observed between HBV infection and metachronous colorectal liver metastases (MET-CRLM) both before and after PSM. Further analysis revealed that HBV replication status did not influence the incidence of CRLM. However, HBV+ participants demonstrated an increased incidence of metachronous extrahepatic metastases, particularly to the lungs. Our findings imply that neither past nor present HBV infection is significantly correlated with the occurrence of SYN-CRLM or MET-CRLM. The absence of an association between HBV replication status and CRLM incidence highlights the importance of incorporating a broader range of factors in the clinical management of CRLM beyond the status of HBV infection.