Delayed infection, late tonsillectomy or adenoidectomy and adult leukaemia: a case-control study

In a population-based case-control study among adults in Italy, of 261 lymphoid and 313 myeloid leukaemias and 1718 controls, a later age at adenoidectomy and tonsillectomy (after age 10 years) increased considerably the risk of lymphocytic (but not myeloid) leukaemia (odds ratio 4.2, 95% confidence interval 1.1-16.2). We propose that late infection is a proliferative stimulus for B-cells.