Abnormal white blood cells can be detected as many as 6 years before an individual with chronic lymphocytic leukemia (CLL) is diagnosed, scientists from the National Cancer Institute report.
The researchers identified 45 individuals participating in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (a prospective study of 77 469 healthy individuals who were followed up for several years) who ultimately developed CLL (Landgren O et al. N Engl J Med. 2009;360:659-667). An examination of blood samples taken from these individuals prior to diagnosis revealed that 44 of them had abnormal white blood cells present in their blood up to 6 years before they were diagnosed. The findings suggest that nearly all individuals who develop this type of cancer may have these abnormal cells first.
Kuehn BM. Blood Cancer Progression. JAMA. 2009;301(12):1217. doi:10.1001/jama.2009.375