Gender and time differences in initial location and histological grade of non-Hodgkin's lymphomas in Southern Sweden

In accordance with international data, non-Hodgkin's lymphomas (NHL) in the Southern Health Care Region of Sweden were more common in men than in wome n and there was an inreasing incidence for both genders in the 1980s and 19 90s. A study of the years 1983 and 1992, i.e. the beginning and the end of a 10-year period, was carried out. Case records for 94% of all adults diagn osed in 1983 and 1992 (220 men and 171 women) were reviewed. The sites of t he lymphomas and malignancy grade (Kiel classification) were recorded. Comp arisons were made between the genders and between the two years studied. Am ong 170 men with nodal lymphomas, 49 were localized (stage I-II) in lymphoi d tissue regional to the respiratory tract, 18 were localized elsewhere and 103 were generalized (stage III-IV). The corresponding sites in 138 women were 28, 33 and 77, respectively (p = 0.002), implying a predominance of st age 1-11 lymphomas regional to the respiratory tract in men and a larger nu mber of localized lymphomas elsewhere, mostly abdominal/retroperitoneal wit h or without inguinal engagement in women. High-grade nodal lymphomas were more common in 1992 (54%) than in 1983 (34%, p = 0.01), suggesting an incre asing number of mainly high-grade lymphomas. For extranodal lymphomas (50 i n men and 33 in women), no clear differences were observed for gender and t he years studied, Risk factors, e.g. occupational hazards, are probably dif ferent for men and women, The gender differences in initial nodal location suggest that initial lymphoma sites may be related to different risk factor s. Epidemiologic studies where both malignancy grade and initial lymphoma l ocations are taken into account may be helpful in defining risk factors.