Sept. 9 (UPI) -- Bone marrow transplant recipients in the 2000s and 2010s are living longer, and with better overall health, than those who underwent the complex procedure in the 1970s, 1980s and 1990s, a study published Thursday by JAMA Oncology found.
However, transplant patients still have a reduced life expectancy compared to the general population, the data showed.
The findings reflect improvements in transplant procedures, supportive care and "more vigilant" patient follow-up, the researchers said.
"There has been a significant decline in mortality and a concomitant improvement in life expectancy," Dr. Smita Bhatia told UPI in an email.
"Still, there is room for improvement and future efforts need to focus on that," said Bhatia, director of the Institute for Cancer Outcomes and Survivorship at the University of Alabama at Birmingham.
Patients who received bone marrow transplants between 2005 and 2014 lost, on average, about four years off their life expectancies, compared with the general population, the data showed.
Those who underwent the procedure between 1990 and 2004 lost nearly seven years, while recipients between 1974 and 1989 lost 10 years.
The findings are based on an analysis of more than nearly 4,800 child and adult transplant recipients age 75 and younger in the United States between 1974 and 2014.
All of the recipients in the study received "allogenic" bone marrow, the researchers said, meaning it recently had been collected from a human source, such as a family member, an acquaintance or an unknown donor.
Donor bone marrow also may be stored for later use in transplant procedures, which are referred to as autologous transplants.
During a bone marrow transplant, or stem cell transplant, healthy blood-forming stem cells are infused to replace damaged or diseased bone marrow. The marrow may be collected from the donor's blood or their hip bone, as well as from a donated umbilical cord.
The procedure is used to treat a variety of so-called "blood cancers," leukemia and lymphoma, as well as severe anemia, Bhatia and her colleagues said.
Cancer recurrence was the most common cause of death among bone marrow transplant patients, accounting for 12% of fatalities within 30 years of the procedure, the data showed.
About 11% of patients died as a result of infections within 30 years of undergoing a transplant.
Nearly 25,000 transplant procedures are performed in the United States annually, according to the Health Resources and Services Administration.
Of these, about 10,000 involve allogenic bone marrow, the Center for International Blood and Marrow Transplant Research estimates.
Although survival after transplants has improved significantly in recent years, up to 25% of recipients die soon after the procedure, the center said.
Still, about 70% of patients with leukemia and lymphoma survive for five years or more after undergoing the procedure.
"While our findings are reassuring with respect to the decline in mortality and improvement in life expectancy, the improvement is not uniform across all groups," Bhatia said.
"There needs to be ongoing effort toward improving outcomes," she said.