Early Use Of Radiation Therapy Associated With Shorter Survival In Multiple Myeloma
Results of a recent retrospective study show that radiation therapy shortly before, or shortly after, the start of drug-based treatment in newly diagnosed multiple myeloma patients is associated with lower overall survival.
The results are based on information for 78,095 multiple myeloma patients from the United States whose data were reported to the National Cancer Data Base between 2004 and 2015.
For their retrospective analysis, the authors of the new study divided the 78,095 patients in their sample into two groups.
One group included the patients who were found to have undergone “upfront” radiation therapy, which the study authors defined as radiation therapy carried out after a myeloma diagnosis and within 90 days before, or up to 14 days after, a patient started drug-based myeloma therapy.
The second group included the patients who did not receive upfront radiation therapy.
Because the study includes data for patients diagnosed up to 15 years ago, survival outcomes are worse than would be expected in data for more recently diagnosed patients.
Nevertheless, there was a noticeable difference in survival between the two groups of patients. Overall survival for patients who received upfront radiation therapy was 3.6 years compared to 4.2 years for patients who did not receive upfront radiation therapy.
Across all patients in the study, 17 percent received upfront radiation therapy. Interestingly, patients were almost 25 percent more likely to receive upfront therapy if they were diagnosed in a community hospital rather than an academic hospital.
The authors of the new study are not able to conclude from their data why upfront radiation therapy is associated with lower overall survival.
One potential explanation is that radiation therapy is more likely to be needed in myeloma that is more aggressive, as it may be more likely to cause bone damage, or in patients whose disease is more advanced due to a comparatively delayed diagnosis.
Another explanation is that bone-related complications that require radiation therapy may limit the extent to which a patient’s disease can be treated.
The authors also explore the possibility that radiation therapy may be more common in patients who, for socioeconomic reasons, have more limited treatment options compared to other patients.
Background
Bone disease is a common complication of multiple myeloma. Approximately 80 percent of multiple myeloma patients show evidence of bone lesions at the time of their diagnosis. Bone-destroying cells are more active in the bones of myeloma patients than bone-forming cells, which ultimately leads to bone destruction and skeletal complications such as lesions, fractures, and spinal cord compression.
Radiation therapy is one approach to addressing some of the bone-related issues caused by multiple myeloma. It is used primarily to reduce bone pain and to prevent or treat bone fractures that can occur in myeloma patients.
Researchers have long known that the more bone lesions a myeloma patient has at diagnosis, the poorer their prognosis tends to be. Prior research has not explored, however, whether upfront radiation therapy has any association with patient prognosis.
Thus, the authors of the new study sought to examine upfront radiation treatment in multiple myeloma patients, including patterns of its use, factors associated with its use, and its potential impact on survival.
Study Design And Results
The authors analyzed data from 78,095 multiple myeloma patients whose information was reported to the National Cancer Data Base between 2004 and 2015. The median patient age in the study sample was 65 years.
Of the 78,095 patient included in the analysis, slightly less than one fifth (17 percent) received upfront radiation therapy. Among the upfront therapy patients, 70 percent received radiation therapy before the start of their drug-based myeloma therapy, and 30 percent started it within 14 days after the start of the drug-based therapy.
Radiation therapy was predominantly administered to the spine (59 percent) and the hip / pelvis area (12 percent).
Factors Affecting The Use Of Upfront Radiation Therapy
The odds of receiving upfront radiation therapy were significantly higher for younger patients, male patients, white non-Hispanic patients, uninsured patients, patients with lower incomes, patients treated at a community hospital rather than an academic hospital, patients who live close to a hospital, and patients who had few or no health issues ("comorbidities") other than their myeloma.
Being treated at a community hospital (rather than an academic hospital) was the strongest factor associated with upfront radiation therapy.
The use of upfront radiation therapy also appears to have declined over time. Among patients in the sample from 2004 to 2009, 18.6 percent underwent upfront radiation therapy. In the patients from 2010 to 2015, in comparison, 16.5 percent underwent upfront radiation therapy.
The study authors speculate that this decline in the use of upfront radiation therapy may be a reflection of physicians becoming more confident over time in the ability of drug-based myeloma therapies to address bone-related issues.
Upfront Radiation Therapy And Survival
Overall survival among the patients in the sample who underwent upfront radiation therapy was 3.6 years versus 4.2 years for the other patients. The three-year overall survival rate was 55.5 percent in the upfront radiation therapy group versus 59.7 percent in the other patients.
The researchers also explored the potential significance of the timing of upfront radiation therapy. They found that survival was noticeably lower in the upfront patients who received radiation therapy within 14 days after the start of their drug-based therapy, compared to the survival seen in the upfront patients who received their radiation therapy prior to the start of their drug-based therapy.
The authors also checked whether they still could find an association between upfront radiation therapy and survival when they looked only at patients who survived at least a year after diagnosis, and also when they looked only at patients who underwent a stem cell transplant.
In both these smaller samples of patients, the researchers continued to find an association between upfront radiation therapy and survival.
To the authors, this speaks in favor of the association between early radiation therapy and overall survival being due to patients with more aggressive myeloma being more likely to need early radiation therapy.
For more information, please see to the study by Orcutt, X. et al., “Prognostic significance of upfront radiation therapy in patients with multiple myeloma,” in The American Journal of Hematology, April 21, 2019 (full text).
Related Articles:
- Importance Of Factors Affecting Multiple Myeloma Survival Changes With Patient Age
- Sustained Complete Response To Initial Treatment Associated With Substantial Survival Benefit In Multiple Myeloma
- Revlimid, Velcade, and Dexamethasone, Followed By Stem Cell Transplantation, Yields Deep Responses And Considerable Overall Survival In Newly Diagnosed Multiple Myeloma
- Recently Diagnosed Myeloma Patients Very Likely To Have Low Testosterone Levels, Study Finds
- Eyelid-Related Complications Of Velcade Therapy: New Insights And Recommendations
Hmmm, I find this interesting on a few levels. Radiation was what got me into this mess in the first place, so I was happy that radiation was not called for in my case. I received induction therapy of Velcade, thalidomide, and dexamethasone (VTD), had a complete response, and have been on a maintenance therapy of Revlimid 10 mg since October 2008. I had many bone lesions at diagnosis, but am thrilled that I do not fall into the researchers' category of poor prognosis. I am hoping to celebrate 11 years of good numbers this summer. I think it goes to show that this disease is a very individual one.