<unk>  <unk>  is the name given to small numbers of leukaemic cells (cancer cells from the bone marrow) that remain in the person during treatment, or after treatment when the patient is in remission (no symptoms or signs of<unk> . It is the major cause of relapse in cancer and leukemia. Up until a decade ago, none of the tests used to assess or detect cancer were sensitive enough to detect<unk> . Now, however, very sensitive molecular biology tests are available, based on DNA, RNA or proteins. These can measure minute levels of cancer cells in tissue samples, sometimes as low as one cancer cell in a million normal cells. In cancer treatment, particularly leukaemia,<unk>  testing has several important roles: determining whether treatment has eradicated the cancer or whether traces remain, comparing the efficacy of different treatments, monitoring patient remission status as well as detecting recurrence of the leukaemia or cancer, and choosing the treatment that will best meet those needs. The tests are not simple, are often part of research or trials, and some have been accepted for routine clinical use.
Minimal residual disease
Immune-related response criteria
Progression-free survival
Toxicity class
Five-year survival rate
Serial interval
Post-transplant survival measure
Natural history of disease