Results of a recent study show that the presence of residual cancer cells and chromosomal abnormalities are strong predictors of early relapse in multiple myeloma patients who achieve a complete response after undergoing stem cell transplantation.

The results were presented last week by Dr. Bruno Paiva, from the Salamanca Hospital Complex in Spain and lead author of the study, at the 16^th Congress of the European Hematology Association (EHA) in London. The authors recommended that myeloma patients with chromosomal abnormalities and persistent residual disease following transplantation should be considered for additional (consolidation) therapy.

Past studies have shown that patients who achieve a complete response following stem cell transplantation have longer overall and progression-free survival times compared to patients who achieve a very good or partial response (see related Beacon ^[1] news). However, the overall survival and time to disease progression for these patients continue to vary.

In this study, the authors aimed to determine factors that could predict early disease progression in patients who achieve a complete response after receiving high-dose therapy and stem cell transplantation.

The researchers analyzed data from two clinical trials.  Among the myeloma patients who participated in the two trials, 241 had a complete response 100 days after receiving high dose therapy and stem cell transplantation using their own stem cells. These patients had a longer time to disease progression compared to the entire study population (71 months versus 52 months) and a higher five-year overall survival rate (73 percent versus 66 percent).

All patients were tested for the presence of residual myeloma cells by a procedure called multiparameter flow cytometry, and 110 patients (46 percent) were tested for chromosomal abnormalities by FISH.

Of the patients who achieved a complete response after transplantation, 12 percent progressed within one year. The patients who progressed had a higher frequency of anemia (low red blood cell counts), stage 2 or stage 3 disease, chromosomal abnormalities, and residual disease.

The study authors determined that residual disease and chromosomal abnormalities could be used to predict early relapse. Of the 58 patients who did not have either of these risk factors, 7 percent relapsed within one year. By contrast, 20 percent of the 45 patients had one risk factor relapsed within one year, and all seven patients who had both risk factors relapsed within one year.

For more information, see abstract 468 ^[2] on the EHA ^[3] website.