Oncologists often turn to radiation therapy to treat painful bone metastasis, but how effective is it? Is the treatment reflected in the patient’s quality of life (QOL)? In a recent paper, investigators reviewed the Dutch Bone Metastasis Study for answers. They theorized that a reduction in pain would mean an improvement in QOL. They also sought to identify which patients were most likely to benefit from the radiation therapy palliation.1
DUTCH BONE METASTASIS STUDY
The controlled Dutch Bone Metastasis Study evaluated 1157 patients who experienced painful bone metastases, from 1996 to 1998.2 Seventeen radiation therapy facilities throughout The Netherlands participated in the study. The clinics randomized patients to treatment schedules of 1 fraction of 8 Gy (the current gold standard for treatment) or 6 fractions of 24 Gy.1
Patients rated their pain, QOL, and overall health weekly for 12 weeks, then monthly for 2 years, until they died, or the study reached its endpoint. The goal of treatment was a reduction in the patients’ pain, and to that end, approximately 75% of patients across both regimens achieved relief.2
Although the original study did not consider tumor site, for this analysis the investigators grouped patients according to the location of their primary tumors. Thus, the 956 patients were divided into three groups: breast cancer, prostate cancer, and lung cancer.1
A NEW ANGLE ON THE FINDINGS
No significant difference was seen in the response rate between the 2 treatment regimens. However, patient response rates changed over time. When the study began, 96% to 97% of patients responded to the treatment. After 6 weeks, the response rate was 73% to 75% of patients, and at the end of the 12 weeks, patient response rate had decreased to 61%.2
Baseline pain scores were comparable in the responding and nonresponding patients; however, other factors were different between the 2 study arms. When these researchers analyzed response rates in relation to cancer location, their findings show patients with prostate cancer responded significantly better than those with lung cancer. In fact, more of the patients who did not respond well to the radiation therapy had lung cancer and visceral metastases.
The responsive group was in better physical condition and less likely to have been on a systemic cancer treatment prior to radiation therapy. They were also younger. Mean age of those who responded well to the therapy was 64 years; mean age of those who did not respond to therapy was 67 years.
Patients who responded well to the radiation treatment lived significantly longer than those who did not. Median survival was 35 weeks for the entire cohort, 16 weeks for the nonresponders, and 45 weeks for the responders. When the study closed, 67% of the responding patients had died whereas 87% of the nonresponding patients had died.1
Those patients who demonstrated a good response to the study’s radiation therapy regimen reported better QOL, especially during the first 3 months of treatment. Patients who had prostate or breast cancer reported a better QOL than those who had lung cancer.
A number of factors related to QOL improved in the patients who responded well to the radiation therapy. For example, psychological and physical symptom distress scores improved in the responders; these scores declined in the nonresponders. In addition, activity-level impairment in the patients who responded remained stable, whereas it deteriorated among nonresponders. These differences worsened over time, becoming clinically relevant.
On multivariate analysis, these researchers found several baseline predictors for pain response: primary tumor in the prostate or breast, absence of visceral metastases, younger age, and use of opioids for analgesia. Which patients will experience improved QOL could not be accurately predicted, the investigators noted. However, 76% of the Dutch Bone Metastasis Study participants responded to the palliative radiation regimens, reporting reduced pain and improved QOL, therefore the researchers conclude that radiation therapy should be offered to all patients with painful bone metastases.1
Bette Weinstein Kaplan is a medical writer based in Tenafly, New Jersey.
1. Westhoff PG, de Graeff A, Monninkhof EM, et al; Dutch Bone Metastasis Study Group. Quality of life in relation to pain response to radiation therapy for painful bone metastases. Int J Radiat Oncol Biol Phys. 2015;93(3):694-701.
2. van der Linden YM, Lok JJ, Steenland E, et al. Single fraction radiotherapy is efficacious: A further analysis of the Dutch Bone Metastasis Study controlling for the influence of retreatment. Int J Radiat Oncol Biol Phys 2004;59(2):528-537.