Epidemiologic overview of malignant lymphoma

Abstract

Malignant lymphoma encompasses a wide variety of distinct disease entities. It is generally more common in developed countries and less common in developing countries. The East Asia region has one of the lowest incidence rates of malignant lymphoma. The incidence of malignant lymphoma around the world has been increasing at a rate of 3-4% over the last 4 decades, while some stabilization has been observed in developed countries in recent years. The reasons behind this lymphoma epidemic are poorly understood, although improving diagnostic accuracy, the recent AIDS epidemic, an aging world population and the increasing adoption of cancer-causing behaviors are suggested as contributing factors. Etiologies of malignant lymphoma include infectious agents, immunodeficiency, autoimmune disease, exposure to certain organic chemicals, and pharmaceuticals. The distribution of many subtypes exhibit marked geographic variations. Compared to the West, T/natural killer (NK) cell lymphomas (T/NK-cell lymphoma) and extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) are relatively more common, whereas other B-cell lymphomas, particularly follicular lymphoma and chronic lymphocytic leukemia/small lymphocytic lymphoma, are less common in Asia. Some subtypes of T/NK-cell lymphomas defined by Epstein-Barr virus association are predominantly Asian diseases, if not exclusively so. Both ethnic and environmental factors play roles in such diversity. In this review, we discuss the geographic distribution and etiology of malignant lymphoma, as well as the trend.

Keywords: Asia; Epidemiology; Malignant lymphoma.

Fig. 1

World map of the estimated age-standardized incidence rates (per 100,000 WHO world standard population) of non-Hodgkin lymphoma and Hodgkin lymphoma combined. Source: GLOBOCAN (http://globocan.iarc.fr/) from CANCERMondial (http://www-dep.iarc.fr/).

Fig. 2

Nominal gross domestic product (GDP) per capita world map 2008. Source: CIA World Factbook 2008. Abbreviation: PPP, purchasing power parity.

Fig. 3

Trends in estimated age-standardized (world) incidence rates of non-Hodgkin lymphoma. Source: CI5plus in CANCERMondial.

Fig. 4

Trends in estimated age-standardized (world) incidence rates of Hodgkin lymphoma. Source: CI5plus in CANCERMondial (http://www-dep.iarc.fr/).

Fig. 5

Age-specific incidence rates (ASR) of non-Hodgkin lymphoma and Hodgkin lymphoma in Korea in 2008. Source: Park et al. [8].

Fig. 6

Age distribution of malignant lymphoma at diagnosis for 1989-2008 at Asan Medical Center. Source: Yoon et al. [7]. Abbreviations: CLL/SLL, chronic lymphocytic leukemia/small lymphocytic lymphoma; MCL, mantle cell lymphoma; FL, follicular lymphoma; MALT, mucosa-associated lymphoid tissue; DLBCL, diffuse large B-cell lymphoma; NK, natural killer; PTCL, peripheral T-cell lymphoma, not otherwise specified; NHL, non-Hodgkin lymphoma.