The results of a small, retrospective analysis show that stem cell transplants may be safe and feasible in multiple myeloma patients over the age of 70.

Based on their findings, the authors of the analysis concluded that older patients should not be excluded from stem cell transplants based on age alone.

However, according to Dr. Ashraf Badros, from the University of Maryland School of Medicine in Baltimore, who was not involved in the study, further trials are needed to confirm and extend these findings so that physicians have a firm basis for treating elderly patients.

“I think we need to focus on the elderly more and trials should address their needs and co-morbidities and even frailty scores so we can make solid recommendations,” explained Dr. Badros in an e-mail to The Myeloma Beacon.

Myeloma patients over the age of 70 years are usually excluded from high-dose chemotherapy and stem cell transplantation because they frequently have other diseases and tend to experience more treatment-related complications, which lower their chances of survival.  

However, results of some recent studies have suggested that stem cell transplants may be feasible in elderly myeloma patients.

To shed further light on the issue, researchers from the MD Anderson Cancer Center in Houston retrospectively analyzed data from 84 multiple myeloma patients ages 70 years and older who had undergone a stem cell transplant with high-dose chemotherapy between July 1999 and June 2010 at their institution. The median patient age was 72 years, and patients had received a median of 2.5 prior therapies.  The median time between diagnosis and the stem cell transplant was 10.2 months.

Patients received 140 mg/m², 180 mg/m², or 200 mg/m² of melphalan (Alkeran) before transplantation. At the time of the stem cell transplant, 20 percent of patients were in very good partial remission, 62 percent were in partial remission, 10 percent had stable disease, and 8 percent had progressive disease.

The overall response rate at day 100 after the transplant was 85 percent, with 18 percent of patients showing a complete response, 12 percent showing a very good partial response, and 55 percent showing a partial response. The researchers pointed out that there was no difference in the overall response based on melphalan dosing.

After two years, progression-free survival was 53 percent, and overall survival was 79 percent. By five years, progression-free survival was 27 percent, and overall survival was 67 percent. The different doses of melphalan did not affect the rates of survival.

The death rate due to causes other than relapse after 100 days was 3 percent, and it increased to 10 percent after three years. Patients below or above 75 years of age showed no difference in mortality at day 100 (2 percent compared to 6 percent).

The most common side effects were gastrointestinal (mouth ulcers, nausea, vomiting, and diarrhea) and affected 88 percent of patients who received 140 mg/m² of melphalan, 95 percent of patients who received 180 mg/m², and 98 percent of patients who received 200 mg/m².

Other side effects, including those related to the nervous system, the heart, and the lungs, also increased at higher melphalan doses.

“Toxicity should be a major concern for elderly patients,” said Dr. Badros. “In my assessment, [severe side effects] are quite serious and should be avoided, and the data again establishes that 140 mg/m² should be the standard of care for elderly multiple myeloma patients.”

The authors found that the most important predictor for treatment outcome was disease status at the time of the stem cell transplant. Patients who received the transplant as part of consolidation therapy after first remission had better overall survival than those who received the transplant after relapse.

Based on these findings, the authors suggested that stem cell transplants should be considered early during treatment. 

For further information, please see the study in Leukemia & Lymphoma (abstract).