Antiviral therapy use and related outcomes in patients with cancer and viral infections: results from SWOG S1204

Purpose: Information is limited about adherence to practice guidelines in patients with hepatitis B virus (HBV), hepatitis C virus (HCV), or HIV infection receiving anticancer treatment. Methods: Newly diagnosed adult cancer patients were enrolled in a multicenter, prospective cohort study (SWOG S1204) during 2013–2017 to evaluate the prevalence of HBV, HCV, or HIV in patients initiating anticancer treatment. At 6 months, records of virus-positive patients were reviewed for antiviral therapy use; anticancer treatment dose reduction; and HBV reactivation (elevated viral load). Categorical variables were compared using chi-square or Fisher’s exact test. Results: Of 3055 enrolled patients with viral testing, 230 had chronic or past HBV, HCV, or HIV with 6-month follow-up data (chronic HBV, 15 patients; past HBV, 158; HCV, 49; HIV, 30). Twenty percent (3/15) of chronic HBV and 11% (17/158) of past HBV patients were co-infected with HCV and/or HIV. Rates of antiviral therapy use by 6 months were as follows: chronic HBV, 85% (11/13); past HBV receiving anti-B cell therapy, 60% (3/5); past HBV receiving systemic anticancer therapy without anti-B cell therapy, 8% (8/105); HCV, 6% (2/35); and HIV, 90% (19/21). Among patients with available data, anticancer treatment dose was reduced in 1 of 145 patients with past HBV and 1 of 42 with HCV. HBV reactivation occurred in 1 of 15 patients with chronic HBV; this patient was not receiving antiviral therapy. Conclusion: Many patients with cancer and viral infections either do not receive guideline-recommended antiviral treatment or receive antiviral treatment that is not recommended in guidelines. Further education is needed to improve adherence to guidelines.