Minimal residual disease and its association with transplant success in Multiple Myeloma.

This study monitored the development of minimal residual disease (MRD) after transplant for multiple myeloma (MM). The main finding was that different patterns of MRD development are associated with varying success after stem cell transplant for MM.

There are many treatments for MM. Patients are often cured fully by treatments for MM. However some cancer cells may remain during treatment. These cells are known as MRD. MRD may also exist after treatment when a patient has no symptoms or signs of disease. Stem cell transplant is commonly used to treat MM. This involves the transfer of stem cells to the patient. Chemotherapy is often used in combination with stem cell transplant. It is important to monitor the effects of MRD on stem cell transplant success in MM.

One hundred and four patients with MM were included in this study. Patients received chemotherapy followed by stem cell transplant. MRD was measured after chemotherapy, 3, 6 9, 12, 18 and 24 months after transplant. The amount of time before cancer worsening was also analysed.

In general, patients had 1 of 4 types of MRD. Thirty-three patients did not develop MRD after chemotherapy and did not have cancer worsening after transplant. Forty-five patients developed MRD after chemotherapy but this was resolved 24 months after transplant. Five patients did not develop MRD after chemotherapy, but had developed MRD 24 months after transplant. Finally, 21 patients developed MRD after chemotherapy and this was present after transplant.

The patients that did not develop MRD during the study had the longest time before disease worsening. In general, these patients survived for about 24 months. Patients with one of the other three types of MRD had disease worsening after 18.6 months on average. Patients who developed MRD after chemotherapy which resolved 24 months after transplant had similar survival to those who did not develop MDR. For the patients who had developed MRD at 24 months after transplant, most patients had developed MRD within 17 months. Survival in general was on average 35 months greater for patients who did not develop MDR than those who developed MRD 24 months after transplant. These patients survived on average 24 months greater than those who developed MRD after chemotherapy which was present after transplant.

The main finding from this study was that monitoring the development of MDR can help to predict the response to chemotherapy and stem cell transplant for patients with MM.

This study only used one type of test to measure MRD. Therefore the results may not be accurate.

If you have questions about the management of MM, please consult a doctor.