ASH 2019, Orlando – Even though autologous hematopoietic cell transplantation (AHCT), a form of stem cell therapy, is an effective treatment for multiple myeloma, only four out of 10 patients receive this therapy. Myeloma occurs most often in people over 60 and the age is usually the main reason for avoiding this procedure.
A new study presented in the 61st American Society of Hematology Annual Congress shows this procedure is safe and effective in older patients and suggests that more people could benefit from the therapy than have typically been offered it.
Older people are often excluded from clinical trials studying transplant because they tend to have a greater number of health issues. Without trials proving newer, aggressive treatments are safe for older patients, doctors may avoid them on the assumption that they are too risky. In addition to showing AHCT is safe and effective in patients over 70 years of age, researchers also found patients fared better when given the conditioning chemotherapy drug melphalan in the normal dose of 200 mg/m2, rather than the reduced dose of 140 mg/m2 often given to older patients.
“This study shows that you can perform these transplants safely in older patients, and the older patients get the same benefits from these treatments as the younger patients do,” said lead study author Anita D’Souza, MD, Medical College of Wisconsin. “In addition, if there are no contraindications other than simply age, it’s worth trying the higher dose of melphalan. Age alone should not be a reason to automatically reduce the dose.”
The study also strengthens the argument that people should not be excluded from clinical trials based on age alone, Dr. D’Souza noted. Myeloma is the second most common blood cancer, and it occurs most often in older adults. Half of patients are age 70 or older at the time of diagnosis.
Using the Center for International Blood and Marrow Transplant Research database, the researchers examined health records of approximately 16,000 patients who received AHCT with melphalan in the United States between 2013-2017. After adjusting for factors such as functional status, comorbidities, and disease stage, they found patients who received their treatments at age 70 or older had similar rates of relapse or disease progression, progression-free survival, and death not caused by a cancer relapse as those 60-69 years of age.
Of patients age 70 and older, about 40% received the full dose of melphalan and 60% received a reduced dose. Those receiving the reduced dose had significantly worse outcomes and lower survival rates. However, Dr. D’Souza noted that it is impossible to determine whether these patients were also more frail to begin with, in which case their poorer outcomes would not necessarily be due to the dosing reduction.
While AHCT specialists often support the use of AHCT in otherwise healthy older patients, Dr. D’Souza said oncologists in community hospitals where many patients are first treated often fail to refer older patients to transplant centers. The researchers noted a significant increase in the proportion of older patients receiving AHCT in 2017 compared to 2013, suggesting that referrals to AHCT specialists increased over time.
In addition to age disparities, the study also speaks to important racial disparities in myeloma care. Myeloma is twice as common in African Americans as whites, yet AHCT rates are significantly lower among black patients. Age likely adds to the barriers for these patients, Dr. D’Souza said.