When cancer metastasizes, or spreads, to a patient’s spine from another part of the body, it can compress the spinal cord, causing pain and movement difficulties. Until recently, the only way to relieve these symptoms and keep the tumor from growing back was to surgically remove the entire tumor.
This major operation pushed back the timing of treatments – such as chemotherapy – for the patient’s primary cancer while the patient recovered from surgery. What’s more, the benefit was often fleeting; in approximately 70 percent of patients, the spinal tumor returned within a year.
Now physicians in Memorial Sloan-Kettering’s Spine Tumor Center have shown that metastatic spine tumors compressing the spinal cord can be controlled quite effectively using a less invasive operation known as separation surgery combined with an intense form of radiation therapy called stereotactic radiosurgery. A new study, published online January 22 in the Journal of Neurosurgery: Spine, reports that this dual approach can reduce spine tumor recurrence from 70 percent to less than 10 percent.
“The impact on spine tumor control and the improved quality of life for this group of patients has been nothing short of miraculous,” says neurosurgeon Mark Bilsky, director of the Spine Tumor Center and senior author of the study. “These patients now avoid a major operation, and most importantly, their tumors don’t return.”
A New Standard Treatment
Over the past decade, stereotactic radiosurgery has revolutionized the management of metastatic spine tumors. Using this approach, radiation oncologists receive guidance from advanced imaging technology to deploy precise, intense radiation using multiple beams that converge on the tumor. This restricts the radiation to the tumor target without harming the spinal cord. In 90 percent of patients with spine tumors, stereotactic radiosurgery alone is sufficient to destroy the tumor.
In patients with spinal cord compression, however, there is too much risk of the radiation damaging the spinal cord, so the standard treatment had been to remove the entire tumor. This extensive operation meant that virtually all patients needed a blood transfusion and five to seven days of recovery time in the hospital — effects that delayed the resumption of treatment for the primary cancer.
About ten years ago, experts in Memorial Sloan-Kettering’s Spine Tumor Center began investigating whether a less aggressive surgical procedure could be more effective if followed with stereotactic radiosurgery. Rather than removing the entire tumor, in this approach the surgeon performs separation surgery, which involves creating a small space (2 to 3 millimeters) between the tumor and spinal cord to relieve pressure, and then stabilizing the spine with specialized bone screws.
This gap allows the tumor to be treated safely with intense radiation. Patients undergoing this less invasive procedure need fewer days to recover in the hospital, and many do not require a blood transfusion.
Advancing Care through Collaboration
Dr. Bilsky, in collaboration with radiation oncologist Josh Yamada and colleagues, report that a retrospective analysis of 186 patients shows that combining separation surgery and stereotactic radiosurgery controlled more than 90 percent of metastatic spine tumors at one-year follow-up. The control was evident regardless of where the cancer originated — for example, the kidney, the lungs, or the colon – and further analysis suggests that the control persists throughout the person’s lifetime.
“This represents a new paradigm in spine tumor treatment,” Dr. Yamada says. “Patients are receiving less-extensive surgery so we can get them back to systemic therapy much more quickly, and the tumor control is lasting. A success rate increasing from 30 percent to more than 90 percent is striking. Our medical oncologists know that once their patients go through this treatment, they usually do not have to worry about another spine tumor interrupting their care.”
The Spine Tumor Center now uses this technique on about 120 metastatic spine tumor patients a year. Drs. Bilsky and Yamada emphasize that this advance in treatment was made possible by Memorial Sloan-Kettering’s collaborative approach, especially the close interaction among neurosurgeons and radiation oncologists.
“The interplay of the two disciplines has been critical,” Dr. Bilsky says. “Sitting down together every day to discuss treatment plans for patients allows us to develop a deep trust for one another’s judgment and a willingness to recognize how a patient will best be served.”