Health Report: New advances against blood cancers
Blood diseases like leukemia used to be a virtual death sentence. However, during the past 50 years, improved treatments have given hope to millions of patients. According to the National Cancer Institute, the five-year survival rate for leukemia in the early 1960s was 14 percent. In the past decade, that figure has improved to 60 percent.
There have been dramatic gains with other blood cancers as well. Myeloma’s five-year survival has gone from 12 to 47 percent, Hodgkin lymphoma from 40 to 88 percent. These changes have been driven by a better understanding of cancer, improved chemotherapies and the development of bone marrow transplants.
September is national blood cancer awareness month, a time to celebrate advances in the field – such as the fact that the survival rate of patients in Scripps Health’s Blood and Marrow Transplant (BMT) Program has more than doubled since the program’s founding 35 years ago.
High-dose chemotherapy can cure cancer, but it also destroys bone marrow, a potentially deadly side effect. Successful marrow transplants were the turning point that allowed cancer specialists to give the higher chemotherapy doses with the goal of curing the disease. Unfortunately, in the early days, finding a donor match was often difficult.
“Thirty years ago, we had problems finding the right donors,” says James Mason, M.D., who directs Scripps Health’s BMT Program. “Back then, many people died waiting for a match. Now we have some amazing resources. For example, the National Marrow Donor Program has more than 10 million volunteer donors in its registry. It gives patients a lot more options.”
To some degree, the improved donor landscape can be traced to better organization. But clinicians have also refined the donation process. Initially, marrow was removed from the pelvis through a large needle – an invasive and painful approach. Now the process uses peripheral blood stem cells, which grow to become marrow cells. Becoming a donor is as simple as giving blood.
Finding more donors was only the beginning. Physicians and researchers have also developed better ways to “type” them to ensure compatibility. Newer DNA tests produce better matches, decreasing the risk of harmful side effects from transplantation.
In some cases, people can use their own marrow. Before receiving chemotherapy, patients donate their own stem cells, which are frozen and transplanted at the appropriate time. This approach is particularly common when treating lymphoma.
While high-dose chemotherapy, followed by bone marrow transplantation, is a proven lifesaver for many patients, it also poses significant risks. Marrow produces both blood and immune cells, so destroying it can expose patients to opportunistic infections. This has been a major research focus for many years and the work has paid off. New antibiotics and other drugs are helping patients resist pathogens.
Another potential risk is graft versus host disease (GVHD). Because transplanted marrow often comes from a donor, it can sometimes generate an immune response against the patient. Fortunately, DNA testing has improved donor-patient matches, reducing the risk of GVHD. New medications have also been developed to combat this complication. Other research has focused on finding biological markers to identify patients susceptible to GVHD.
One of the most significant advances has been the ability to transplant older patients. More often than not, cancer affects people older than 50. However, when bone marrow transplants were first developed, older patients had trouble tolerating the procedure – the treatment was just too harsh.
This was a frustrating impasse, as many patients could not take advantage of marrow transplants. However, new approaches have emerged such as “mini-transplants,” which are gentler regimens that allow people up to 70 to successfully endure transplantation with lower risk of serious complications.
Bone marrow transplants and other blood cancer therapies have made an enormous difference in patient survival, but the work is far from done. Researchers and clinicians are investigating new treatments and refining old ones. The ultimate goal is to completely cure these diseases.
For more information, visit scripps.org/KUSI or call 858-240-5075.