Screening for Occult and Overt Hepatitis B Virus Infection in Patients of Cancer before Receiving Chemotherapy: Looking Beyond HBsAg Testing

Background: Hepatitis B virus (HBV) infection is increased in cancer patients and those receiving chemotherapy are at risk of HBV reactivation with high mortality. Screening for occult and overt HBV infection is not widely practiced in cancer patients. Objectives: To assess the prevalence of occult and overt HBV infection in cancer patients at initial diagnosis prior to receiving chemotherapy(CT). Methods: At initial diagnosis of cancer, patients were examined for any evidence of liver disease followed by screening for serum markers of HBV infection (HBsAg, total anti HB core, anti HBs antibody and HBV DNA). Results: Isolated anti HBsAg positivity and previous resolved HBV infection was seen in 98(14.2%) and 88/690 (12.7%) patients respectively. HBV infection was seen in 68/690(9.8%) patients which included overt and occult HBV infection in 55/690 (8%) and 13/690 (1.9%) respectively. Overt and occult HBV infection in hematological cancers was more as compared to solid cancers [16/140(11.4%) vs 39/550 (7%), p=0.09] and 5/140(3.6) vs 8/550(1.4) p=<0.15] respectively. There was no significant difference in HBsAg positivity based on sex [31/393(7.8%) men vs 24/297(8%) women, p=0.9)], age [7/74(9.4 %) < 20yrs, 39/490 (7.9 %), 21-60 yrs, 9/126 (7.1%) > 60yrs), p=0.84], previous blood transfusions (BT) [13/170 (7.6%) BT vs 42/520 (8.0%), no BT, p=0.9)], history of jaundice [7/88 (8%) vs 35/602 (5.8%, p=0.8)] or ALT values, [42/545(7.7%) vs 13/145(7%), p=0.8)]. Conclusion: HBV infection is increased in cancer patients. Patients should be screened for both occult and overt HBV infection by testing serum HBsAg, HBV DNA and anti HB core antibody.