Haematopoietic cancer and medical history: a multicentre case control study

Background-Viruses (such as Epstein-Barr virus) and pathological conditions (mainly involving immunosuppression) have been shown to increase the risk of haematolymphopoietic malignancies. Other associations (diabetes, tonsill ectomy, autoimmune diseases) have been inconsistently reported. Methods-The association between different haematolymphopoietic malignancies (lymphomas, myelomas and leukaemias) and the previous medical history has been studied in a population-based case-control investigation conducted in Italy, based on face to face interviews to 2669 cases and 1718 population c ontrols (refusal rates 10% and 19%, respectively). Controls were a random s ample of the general population. Results-Previous find firmed concerning the association between non-Hodgkin 's lymphoma (NHL) and lupus erythematosus (odds ratio, OR=8.4; 95% CI 1.6, 45), tuberculosis (OR=1.6; 1.05, 2.5) and hepatitis (1.8; 1.4, 2.3). An ass ociation was found also between NHL and maternal (OR=2.8; 1.1, 6.9) or pate rnal tuberculosis (OR=1.7; 0.7, 3.9). Odds ratios of 4.0 (1.4, 11.8) and 4. 4 (1.1, 6.6) were detected for the association between NHL and Hodgkin's di sease, respectively, and previous infectious mononucleosis, but recall bias cannot be ruled out. No association was found with diabetes, tonsillectomy and adenoidectomy. An association with malaria at young age and "low grade " lymphatic malignancies is suggested. One interesting finding was the obs ervation of four cases of poliomyelitis among NHL patients, one among Hodgk in's disease and one among myeloid leukaemia patients, compared with none a mong the controls (Fisher's exact test for NHL and Hodgkin's disease, p = 0 .03, one tail). Conclusions-Some of these findings are confirmatory of previous evidence. O ther observations, such as the putative role of the polio virus and of mala ria are new. A unifying theory on the mechanisms by which previous medical history may increase the risk of haematolymphopoietic malignancies is still lacking.