Malignant lymphoma in Nebraska and Guangzhou, China: a comparative study

Two hundred thirty-four consecutive cases of malignant lymphoma (192 non-Hodgkin's lymphomas and 42 Hodgkin's disease) from Guangzhou, China, and 589 cases (498 non-Hodgkin's lymphomas and 91 Hodgkin's disease) from the University of Nebraska Lymphoma Registry were examined in a retrospective histopathologic analysis and the results compared to those of the National Cancer Institute (NCI) Working Formulation Summary. Aggressive non-Hodgkin's lymphoma was excessive in Guangzhou (82.3 per cent; P less than 0.001) and Nebraska (80.3 per cent; P less than 0.001) when compared with the NCI data (54.2 per cent). The small noncleaved cell, lymphoblastic, and diffuse mixed-cell subtypes were more frequent in China (15.6 per cent each; P less than 0.001), whereas the small lymphocytic, follicular large cell, and immunoblastic subtypes predominated in Nebraska (8 per cent, 8.4 per cent, and 21.8 per cent, respectively; P less than 0.001). The overall median age of onset for non-Hodgkin's lymphoma was 42.0 years in Guangzhou and 63.5 years in Nebraska. Hodgkin's disease represented 18 per cent of the malignant lymphomas in Guangzhou and 15 per cent in Nebraska. The mixed-cellularity type was most common in Guangzhou (52 per cent; P less than 0.001) and the nodular-sclerosing type in Nebraska (56 per cent; P less than 0.010). The low median age and excess of certain aggressive subtypes of non-Hodgkin's disease in Guangzhou suggest a possible viral etiology, whereas the excess of certain subtypes of non-Hodgkin's lymphoma in Nebraska may be related to intense agricultural activity.