This is a prospective, single-center, open-label, randomized controlled trial aimed to evaluate the efficacy and safety of entecavir and tenofovir versus entecavir alone in the antiviral treatment of HBV DNA positive B-cell lymphoma patients.

This study plans to enroll about 120 participants in total. Recruitment will last for 2 years.

The study visit will take place on the first day of each cycle of therapy until the end of the treatment.

Participants who meet the inclusion/exclusion criteria were randomly assigned to receive entecavir and tenofovir or entecavir alone after signing the informed consent. HBV DNA will be measured before each cycle of chemotherapy or immunotherapy. When the copy count of HBV DNA drops below 1*10^3/L, entecavir single agent will be given orally, until one year after the cycle of therapy.

Treatment response will be evaluated routinely after chemotherapy or immunotherapy.

Within 2 years after the last participant is enrolled, participants' survival information will collected by telephone and/or clinical visit every 3 months after the last visit (i.e. date and cause of death, subsequent cancer treatment, etc.), if there is no withdrawal of the informed consent form.

Inclusion Criteria:

• Treatment-naive, pathologically confirmed diagnosis of B-cell lymphomas with the viral load of HBV DNA>1*10^3/L
• Age≥18 years old
• Measurable lesions in radiographic images, defined as at least one well-defined lesions/knots, with both the long diameter and the short diameter≥1.5cm
• Life expectancy of at least 3 months according to researchers' judgement
• Written informed consent must be provided by participants or their legal representatives prior to any research examination or procedure

Exclusion Criteria:

• Creatine<50mL/min
• Any medical condition that may affect the conduction of this study according to researchers' judgement