The difference between p53 mutation frequency in haematological and non haematological malignancies: possible explanations

p53 gene mutations are the most frequent alterations in human cancers. In the published literature, a highly significant statistical difference between the prevalence of p53 mutations in haematological (H) and nonhaematological (NH) malignancies can be found. However, no consistent reasons have been suggested to explain it. We propose two non-exclusive possibilities: (i) in H tumours p53 is altered with the same frequency as in NH tumours, but mechanisms other than mutations are involved and (ii) in H malignancies the prevalence of p53 mutations is much lower than in NH cancers because other genetic disturbances are involved. We hypothesized that retention of wildtype p53 in H cancers may be a consequence of: (a) the presence of telomerase activity in haematological cells and/or (b) the absence of hypoxia in the majority of H tumours. (C) 1999 Harcourt Publishers Ltd.