In a first-of-its kind study, researchers evaluated the association between Human Development Index data and the prevalence of Hodgkin lymphoma.
Hodgkin lymphoma (HL) has a global annual incidence of about 83,000, causing more than 23,000 deaths globally, per the online database GOBOCAN 2020. Approximately 95% of all cases of HL are of classical Hodgkin lymphoma (cHL). According to the World Health Organization’s classification, cHL is further divided into four sub-types: nodular sclerosis (NS), mixed cellularity (MC), lymphocyte rich (LR), and lymphocyte depleted (LD).
Among these subtypes, about 70% of cases are of NS. NS is associated with favorable clinical outcomes. It is known that there is a substantial geographical variance in the incidence of various cHL subtypes.
A systematic literature review published in the journal Health Sciences Review aimed to identify the association between the Human Development Index (HDI) and the incidence of various cHL subtypes.
HDI and Incidence of Classical Hodgkin Lymphoma Subtypes
Studies from 34 nations were included: 9 European, 4 African, 7 Middle-Eastern, 5 South and South-Eastern Asia, 3 from North and Central America, and 6 from South America, using patient data between the years 1980 and 2021. Thus, it was representative of the global population. Then, the prevalence of various cHL subtypes was correlated to Human Development Index (HDI) data for individual nations.
The study found that NS cases were more likely to be diagnosed in North and Central America, Europe, or nations with higher HDI. The mean incidence of the NS subtype was 65% in North America and 61% in Central America. These nations had an HDI mean value of 0.79 for North and Central America and 0.81 for Europe. On the other hand, NS cases were 31% in Africa (HDI mean value 0.43) and 36% in South Asia (HDI mean value 0.63).
The MC subtype was more common in East and South Asia (50%), followed by Africa (46.5%), and was lowest in North and Central America (23%) and Europe (26%). The LR subtype was more common in the Middle East (8.5%) and Europe (8.3%), followed by East and South Asia (8%), North America (7.3%), and Africa (7.9%). The LD subtype was most common in Africa (13.7%), followed by East and South Asia (4.7%).
The Bottom Line
This is one of the first studies to demonstrate an association between the incidence of cHL subtypes and HDI or socioeconomic status, with NS more common in nations with higher HDI values and MC more common in low-HDI nations. The authors state that these disparities could be partially explained by a higher prevalence of Epstein-Barr virus (EBV) and Human Immunodeficiency Virus (HIV) infections. It is likely that overcrowding of households in low-income urban areas may result in early infection with EBV in some nations, leading to higher MC and LD prevalence in nations with lower HDI and in rural areas.
References:
Moscona-Nissan, A., Mancilla-Osuna, M. F., Bardán-Duarte, A., & Macías, M. E. R. (2023). Classical Hodgkin Lymphoma Histologic Subtypes Distribution among Geographical Regions and Correlation with Human Development Index. Health Sciences Review, 9, 100117. https://doi.org/10.1016/j.hsr.2023.100117
