CHICAGO -- For cancer patients with metastatic spinal cord compression, a single dose of radiation can be enough to preserve their ability to walk, a researcher said here.
In a randomized trial, patients given the single dose and those given standard radiotherapy spread over 5 days had similar outcomes after 8 weeks, according to Peter Hoskin, MD, of the Mount Vernon Cancer Centre in Middlesex, England.
Given that the median survival of the patients was just 13 weeks, "a single dose has enormous advantages," Hoskin told reporters at the American Society of Clinical Oncology (ASCO) annual meeting.
He told ľֱ that the findings should establish the single dose as standard practice in patients with metastatic spinal cord compression.
"A single dose of radiation is more than adequate for their treatment," he said. "It will not compromise the likelihood of maintaining ambulation or recovering ambulation and it's associated with no more adverse events than the more protracted course of treatment."
Metastatic spinal cord compression is a common complication of advanced cancer -- Hoskin said there are some 45,000 cases a year in the U.K. -- and the radiation treatment is aimed at preserving neurological function, maintaining mobility, and relieving pain.
There is currently no completely standard treatment but most patients get a fractionated course of radiotherapy over several days.
The consequence of the condition can be "truly devastating" for patients and their families, commented ASCO expert Joshua Jones, MD, of the University of Pennsylvania in Philadelphia.
"This is the first study that really shows equal outcomes," Jones told reporters, adding the shorter course of treatment would give patients "more time with family and more time doing what they want to do," instead of coming to hospital for radiation.
He added that it's still not clear what the best option would be for patients likely to live longer than those in the study.
Indeed, the evidence is compelling, but more long-term data would be helpful to physicians, commented , of New York-Presbyterian Hospital in New York City, who was not part of the study.
The study is "strong enough to make this a new standard of care," Wang told ľֱ, adding that "I am looking forward to seeing longer follow-up with respect to patients' functional status beyond 8 weeks."
He noted that many patients are unable to come for daily radiotherapy, so the option of a single treatment with equivalent outcomes is likely to be attractive, both in terms of quality of life and cost.
Hoskin's group enrolled 688 patients with various forms of metastatic solid tumors and randomly assigned them to get either a single dose of 8 Gy or five daily doses of 4 Gy each. The primary endpoint of the study, designed as non-inferiority trial, was ambulatory status 8 weeks after the end of the treatment.
The investigators used a 4-point scale for ambulatory status:
- 1:able to walk without aid
- 2: able to walk with aid
- 3:unable to ambulate
- 4: flaccid paraplegia
They also looked overall survival (OS) and adverse events.
At study entry, 66% of patients had ambulatory status 1 to 2, Hoskin reported.
At 8 weeks, there were no significant differences between the groups in the proportion who maintained, improved, or lost ambulatory status. In particular, 69.5% of patients who received the single dose and 73.3% of those who got five doses still had ambulatory status 1 or 2, showing that both courses helped patients stay mobile.
Median OS was not statistically different -- 12.4 weeks with a single dose and 13.7 weeks with five doses (hazard ratio 1.02, 95%CI 0.86-1.21, P=0.81) -- and the proportion of patients with severe side effects was similar, although mild side effects were less common in the single-dose patients, he reported.
Disclosures
The study had support from Cancer Research UK. Hoskin disclosed a relationship with Varian ľֱ Systems.
Jones made no disclosures.
Wang disclosed relationships with AbbVie, AstraZeneca, Doximity, and Wolthers Kluwer.
Primary Source
American Society of Clinical Oncology 2017
Source Reference: Hoskin P, et al "SCORAD III "Randomized noninferiority phase III trial of single-dose radiotherapy (RT) compared to multifraction RT in patients (pts) with metastatic spinal canal compression (SCC)" ASCO 2017;abstract LBA 10004.