As the spinal column is the most common site for bone metastasis, metastatic spinal tumors are the most common type of malignant lesions of the spine. They account for an estimated 70 percent of all spinal tumors. Estimates also indicate that at least 30 percent and as high as 70 percent of patients with cancer will experience spread of cancer to their spine. Primary cancers that commonly spread to the spine are lung, breast, and prostate. Other cancers that spread to the spine include gastrointestinal tract, lymphoma, melanoma, kidney, sarcoma, and thyroid.
Non-mechanical back pain, especially in the middle or lower back, is the most frequent symptom of metastatic spinal tumors. Pain may spread beyond the back to the hips, legs, feet or arms and may worsen over time, even when treated by conservative, nonsurgical methods that can often help alleviate back pain attributed to mechanical causes. As the malignant tumor grows and compresses the spinal cord, nerve roots, blood vessels or bones of the spine - pain and other symptoms may occur.
Researchers at the M.D. Anderson Cancer Center in Houston investigated the efficacy of stereotactic body radiosurgery (SBRS) in treating patients with cancer that metastasized to the spine. The results of this study, Prospective Study of Cancer Control and Patient Reported Outcomes for Spinal Metastases treated with Stereotactic Body Radiosurgery, will be presented by Eric L. Chang, MD, 9:45 to 9:59 am, Wednesday, May 6, 2009, during the 77th Annual Meeting of the American Association of Neurological Surgeons in San Diego. Co-authors are Pamela K. Allen, PhD, Charles Cleeland, PhD, Patricia Grossman, RN, David Kornguth, MD, Anita Mahajan, MD, Tito Mendoza, PhD, Laurence D. Rhines, MD, Almon S. Shiu, PhD, and Xin Shelley Wang, PhD.
Stereotactic radiosurgery (SRS) uses sophisticated image-guidance to precisely target a narrow x-ray beam and deliver a high concentrated dose of radiation to the affected area. SBRS is a recent and emerging application of SRS to tumors in the spine, liver, lung and other body sites. SBRS is generally delivered in a single or a small number of treatment sessions.
"The purpose of this study was to analyze the effectiveness of SBRS on cancer control and measure patient-reported outcomes in cases of spinal metastases," stated Dr. Chang. One hundred twenty-one patients with cancers of the lung, breast, skin, kidney, colon, and connective tissues were enrolled over a 5-year period from 2002 to 2007. There were 136 spinal metastases treated with SBRS. Tumor control was assessed using serial spinal MRI. Patient Reported Outcome (PRO) was assessed using validated instruments including the Brief Pain Inventory (BPI) and the M.D. Anderson Inventory (MDASI). The following results were noted:
-The 6-month and 1-year survival rate for spinal metastasis progression free survival (PFS) was 90 percent and 84 percent respectively.
-The median survival for the study group was 21 months.
-Patient survival at 1 year was 65 percent, and at 2 years was 42 percent.
-Using strict criteria for complete pain relief, the number of patients doubled who were completely pain-free at 3-months and 6 months post-SBRS compared to baseline.
-The five "most severe" symptoms prior to SBRS were fatigue, pain, sleep disturbance, drowsiness, and distress. At 6 months, significant reductions were seen in all of these symptoms.
-No cases of radiation myelopathy have been observed to date.
-Acute toxicities were manageable, and no late complications involving the spinal cord have been observed to date.
"In conclusion, SBRS in patients with spinal metastases is a safe and effective treatment modality, yielding high 6-month and 1-year PFS rates and dramatic reductions in pain and symptoms related to the metastatic cancer," concluded Dr. Chang.
The author reports no conflicts of interest.
Founded in 1931 as the Harvey Cushing Society, the American Association of Neurological Surgeons (AANS) is a scientific and educational association with more than 7,400 members worldwide. The AANS is dedicated to advancing the specialty of neurological surgery in order to provide the highest quality of neurosurgical care to the public. All active members of the AANS are certified by the American Board of Neurological Surgery, the Royal College of Physicians and Surgeons (Neurosurgery) of Canada or the Mexican Council of Neurological Surgery, AC. Neurological surgery is the medical specialty concerned with the prevention, diagnosis, treatment and rehabilitation of disorders that affect the entire nervous system, including the spinal column, spinal cord, brain and peripheral nerves.
Media Representatives: If you would like to cover the meeting or interview a neurosurgeon - either on-site or via telephone - please contact the AANS Communications Department at (847) 378-0517 or call the Annual Meeting Press Room beginning Monday, May 4 at (619) 525-6252.