If the specimen contains a substantial burden of circulating tumor cells, testing and results may be affected. Specifically, this can result in:
- sample failure (during quality control processes)
- deletion/duplication analysis failure
- false negatives due to changes in the tumor cell line concealing inherited variants
- false positives due to changes in the tumor cell line appearing to be inherited
If the malignancy is not presently circulating in the peripheral blood, it is likely that the test will be completed and that results will not be affected.
If there are actively circulating tumor cells, testing a sample type not derived from blood (such as skin biopsy) is suggested. While we do not accept this sample type directly, we can accept DNA derived from skin or muscle. However, we cannot guarantee deletion/duplication analysis, as success rate varies based on sample quality.
Finally, it is important to note that we cannot process blood or saliva samples from patients that had allogeneic (non-self) bone marrow or stem cell transplants.