Yet another important observational study, termed Screening Circulating Tumor Cells as a Non-invasive Cancer Test in 1,585 Asymptomatic Adults (ICELLATE1), has been published. This time in the Journal of Integrative Oncology.
ICELLATE1 is all-comers, single center study that includes individuals in the age bracket 20-80 years that do not belong to any known risk group for cancer, and who do not feel sick. Any individual with a current diagnosis or history of any type of tumor was therefore excluded from the study. A total of 1,585 individuals were screened to investigate if tumor cells, CTCs, had invaded their blood circulation. CTCs in their blood samples may be a clinically useful test for the early detection of cancer.
It turns out that 1.7% were found to have one or more CTC in their blood samples, i.e may be at risk for developing symptoms in the future. This percentage is in line with what one would expect for a successful early detection screen among normal, healthy, people. The number also corresponds well to the already published ICELLATE2 study. ICELLATE2 is a different study made up, not of normal healthy people, but of a high-risk population, were one would expect a higher number of individuals with CTCs in their blood samples. Indeed, in that study CTCs were found in 3.2%, almost twice as many. The association of percentage of CTCs with known risk for cancer and the large size of these two studies gives some confidence that the numbers are representative of the population at large.
The present findings therefore identify screening for circulating tumor cells as a promising new screening test for the early detection of cancer.