Test Background It is possible for a patient with ALL to demonstrate no symptoms or signs of cancer, but still have a very small number of leukaemic cells remaining in the blood that are unlikely to be readily detected under the microscope. This presence of a few circulating leukaemic cells is known as MRD and is the major cause of relapse in ALL. Molecular testing employs sensitive techniques to measure even minute levels of cancer cells when outnumbered and surrounded by normal cells.
Clinical Indications MRD testing plays an important role in determining whether treatment has been successful, comparing the efficacy of different treatment plans a patient may undergo, monitoring patient remission status and monitoring for recurrence.
Sample Required Blood or bone marrow in EDTA (lavender top) within 72 hours of collection
Sample Volume 10-20 mL blood or 1-2 mL bone marrow
Turnaround Time 10 working days
Notes At times, it may be necessary to refer work to other laboratories or consultants. This requirement is assessed on a case-by-case basis. Referral centres are selected based on the EQA schemes in which they participate, any reported EQA exceptions, average turnaround times and accreditation status. There are occasions where a centre without accreditation status is used; this is because it is a national referral centre and, on this basis, is deemed expert in this field. When cases require a specialist second opinion, they are referred by our pathologist to another pathologist, in line with the West London Cancer Network guidelines.