His research focused on factors associated with increased risk of developing blood cancers. Using meta-analytical methods, he identified smoking as a risk factor for Hodgkin lymphoma, transfusions for chronic lymphocytic leukemia, and an increased risk of blood cancers in individuals with diabetes. He has also used large databases such as SEER and Medicare to study rare lymphomas such as Burkitt, marginal zone, lymphoplasmacytic lymphoma and HIV-associated lymphomas. His work has been published in the Journal of Clinical Oncology, Blood, Cancer, and the American Journal of Hematology.