Chronic diseases, medical history and familial cancer, and risk of leukemia and non-Hodgkin's lymphoma in an adult population: a case-control study

This investigation was aimed at evaluating the association between chronic diseases, medical history and familial cancer, and the risk of developing hematological malignancies. Data were drawn from a population-based case-control study carried out to assess the risk of non-Hodgkin's lymphoma and leukemia in an adult population exposed to environmental air pollution in Northern Italy. Each case was classified according to the WHO ICD-O-3 classification. Statistical analyses were performed by multivariable unconditional logistic regression in 573 interviewed subjects (199 lymphoid cases, 95 myeloid cases, and 279 healthy controls). Lymphoid malignancies were associated with a history of gastroduodenal ulcer (OR 2.1, 95 % CI 1.2-3.6), rheumatoid arthritis (OR 4.4, 95 % CI 1.3-19.0), anemia (OR 3.3, 95 % CI 1.2-9.3), cholecystectomy (OR 2.9, 95 % CI 1.0-8.0), heavy diagnostic X-ray exposure (OR 2.1, 95 % CI 1.3-3.7), and a familial risk of non-Hodgkin's lymphoma (OR 10.1, 95 % CI 1.3-458). Myeloid malignancies were associated with non-neoplastic thyroid diseases (OR 6.2, 95 % CI 1.7-35.6) and anemia (OR 6.8, 95 % CI 2.0-23.1). Subgroup analysis highlighted an excess risk of MALT in patients with gastroduodenal ulcer (OR 5.3, 95 % CI 1.04-23.7) and of AML in patients with rheumatoid arthritis (OR 6.9, 95 % CI 1.2-38.1), and of MDS in subjects exposed to heavy diagnostic X-ray (OR 3.4, 95 % CI 1.03-11.2) when the analysis was restricted to irradiation of pelvis, abdomen, or thorax. Most observed associations confirm results from previous studies. The higher risk of lymphoid malignancies among patients with a history of cholecystectomy needs further investigations.