The descriptive epidemiology of non-Hodgkin's lymphoma (NHL) (1984–1988) in parts of England and Wales is described by low grade (LG) and high grade (HG) subtypes. Major differences in age specific incidence are evident particularly in those under 35 years where LG-NHL is virtually absent in childhood and rare in young adulthood. Over the 5 year period of registration of cases significant increases in incidence were noted for males with both HG and LG disease.

The geographical analyses demonstrate clear epidemiological differences between LG-NHL and HG-NHL. The SMRs for 22 English and Welsh counties are not correlated for LG and HG-NHL disease, whose distributions are significantly different. Regression analyses at the electoral ward level show a strong association between LG-NHL and high-socio economic status and there is a weaker link between HG-NHL and residence in an urban area. Formal comparison of LG and HG-NHL shows significant differences for the effect of socio-economic grouping but not for urban-rural status.

There is strong evidence to show that major differences exist in patterns of LG and HG-NHL for age specific incidence, geographical distribution and area risk factors. Interpretation of these epidemiological features are highly suggestive of differing aetiologies.