Date of Award
5-2022
Document Type
Dissertation
Degree Name
Master of Medicine (MMed)
First Supervisor/Advisor
Samuel Nguku Gitau
Second Supervisor/Advisor
Edward Chege
Third Supervisor/Advisor
Anne Mwirigi
Department
Imaging and Diagnostic Radiology (East Africa)
Abstract
Introduction: Patients with Human Immunodeficiency Virus (HIV) are known to exhibit atypical pattern of lymphoma on imaging. There is paucity of literature on differences in tumour volume or burden of disease amongst HIV positive patients compared with HIV negative patients and how this correlates with clinicopathological parameters of aggressiveness and effects on prognosis.
Objective: The purpose of this study was to evaluate the tumour burden of non-Hodgkin’s lymphoma in HIV positive patients compared with HIV negative and how this correlates with the clinicopathological parameters of aggressiveness and the overall clinical outcome.
Methods: This was a retrospective analytical cross-sectional study. All patients diagnosed with non-Hodgkin lymphoma from January 2011 to June 2021 were identified. These were then stratified into those with HIV and those without HIV and the tumour burden and site of disease on CT imaging calculated using the Lugano classification for lesion measurement. The international prognostic score, the histological type and Ki-67 index were recorded. Continuous variables were analyzed using the Kruskal Wallis test while the categorical variables were analyzed using the Fischer’s Exact test. Logistic regression was performed to assess if HIV is independently associated with clinical outcome after controlling for extranodal disease.
Results: Out of the 92 patients with non-Hodgkin lymphoma, 47 were HIV positive while 45 were HIV negative with a median age of 45 years. The median sum of product diameters used to measure the tumour burden was 102.6 [51.7, 173.1] with no difference seen in the two groups. The extranodal disease was significantly higher in the HIV positive group (85.1%) while exclusive nodal disease was seen predominantly in the non-HIV group (66.7%) (p value <0.001). Although, there was no difference in the clinical IPI score and Ki-67 between the two groups, when comparing the IPI score with the volume of disease, the patients who had a higher burden of disease had poor prognosis and vice versa but this was only statistically significant for the non-HIV group (p value <0.001). Complete treatment response was higher in the non-HIV group 54.5% compared to 20.9% for the HIV group (p value <0.001). More HIV positive patients succumbed, 37.2% compared to the 4.5% for non-HIV patients (p value <0.001).
Conclusion: HIV related lymphoma remains a poorly understood subset of lymphoma. Imaging plays a critical role in staging of the HIV lymphoma. The significant imaging finding in HIV related lymphoma is presence of extranodal disease irrespective of the overall imaging burden. Furthermore, the clinical IPI score and Ki-67 which apply well for HIV-negative patients may not be apply for HIV related lymphoma.
Recommendations: We propose a separate clinical prognostication index for HIV related lymphoma that incorporates the stage of the disease and a higher weighting given to presence of extra nodal disease. Further studies are also needed to determine the initiation, type of HAART and the type of chemotherapy regimens and how this relates to occurrence and prognosis of HIV related lymphoma.
Recommended Citation
Loyal, P. K. (2022). Radiological comparison of tumour burden of lymphoma in HIV positive and HIV negative patients (Unpublished master's dissertation). Aga Khan University, East Africa.