Incidence of Hodgkin lymphoma in HIV-positive and HIV-negative patients at a tertiary hospital in South Africa (2005 - 2016) and comparison with other African countries

Abstract

BACKGROUND. Hodgkin lymphoma (HL) is the most common non-AIDS-defining cancer in HIV-positive patients. Studies on South African (SA) populations have described the prevalence as 7 - 17% of all lymphomas, 8 - 27% of head and neck lymphomas, 9% of lymph node biopsies and 4% of HIV-related malignancies. OBJECTIVES. To describe the incidence of HL at our centre between 2005 and 2016 by year, gender, HIV status, histological subclassification and bone marrow involvement, and compare these findings with similar SA and African studies. METHODS. This was a retrospective study of all incident HL cases diagnosed in the Department of Pathology, National Health Laboratory Service, Tygerberg Academic Hospital, Cape Town. Follow-up, relapsed and referral cases were excluded. A positive diagnosis of HL was confirmed by either lymph node or bone marrow biopsy and was based on morphological and immunohistochemical findings in accordance with the World Health Organization classification. RESULTS. There were 303 incident cases of HL diagnosed. The incidence increased from 2005 to 2011, with a spike in cases in 2008 and a subsequent decline overall after 2011. The highest proportion of cases was in the 25 - 49-year-old age category (51.1%). There were 77 HIV-positive patients (25.4%), of whom 53 (68.8%) had CD4+ counts <500 cells/μL. In keeping with other African studies, the main subtypes were nodular sclerosis HL (49.8%) and mixed-cellularity HL (23.1%). Bone marrow biopsy following lymph node diagnosis of HL confirmed involvement in 23.7% of patients. CONCLUSIONS. Absolute numbers of cases of HL at our centre have increased since the roll-out of antiretroviral therapy (ART) to the public sector. The recent change in policy to make ART available to all HIV-positive patients independent of CD4+ count suggests that patients will survive longer and are therefore at increased risk of developing HL. We anticipate that numbers of HL cases will increase or remain high in the coming years, and we need to prepare for this.