Cancers arise from multiple acquired mutations, which presumably occur over many years. Early stages in cancer development might be present years before cancers become clinically apparent, according to a new study published in the New England Journal of Medicine.
Data where analysed from 12,380 persons blood cells DNA. Some types of mutations (permanent changes of the genes) were observed in 10% of persons older than 65 years of age but in only 1% of those younger than 50 years of age. Approximately 42% of hematologic cancers in this cohort arose in persons who had that mutations at the time of DNA sampling, more than 6 months before a first diagnosis of cancer. Analysis of bone marrow–biopsy specimens obtained from two patients at the time of diagnosis of acute myeloid leukemia revealed that their cancers arose from the earlier clones. A subset of the genes that are mutated in patients with myeloid (bone marrow) cancers is frequently mutated in apparently healthy persons; these mutations may represent characteristic early events in the development of hematologic cancers.