Experts explain their approach to treating patients who are living longer with cancer that has spread to the spine, as the options for metastatic spine tumours increase.
Every kind of cancer can spread to the spine, yet two physician-scientists who treat these patients describe a paucity of guidance for effectively providing care and minimising pain.
To resolve the confusion and address the continually changing landscape of spine oncology, a recent Michigan Medicine-led publication details a guide to explain the management of spinal metastases.
Published in The Lancet Oncology, the work is the result of a literature review of all existing studies, and pulls in experts from across the world to provide insight. The goal, says senior author Nicholas Szerlip (Michigan Medicine Neurosurgery Clinic, Taubman Center, Ann Arbor, USA), is to get all providers on the same page.
First author Daniel Spratt (Department of Radiation Oncology, University of Michigan Health System), who with Szerlip co-founded the University of Michigan’s multidisciplinary spine oncology clinic, says patients with spine metastases are commonly managed in silos without integrated care. A patient with a spine metastasis might see a variety of subspecialty doctors. Recommendations could range from pain management to more aggressive treatment, and referring providers do not always know what will come out of a referral to spine oncology experts, or when a referral is necessary.
Szerlip comments, “Spine oncology is such a multidisciplinary pathology. We wanted to form a transparent understanding so everyone, from the oncologists and primary care providers to fellow neurosurgeons who aren’t specifically trained on this, could lean on one algorithm in [a] language we can all understand.”
Spratt describes the algorithm, a report from the researchers’ new International Spine Oncology Consortium, as a step-by-step method designed to help comprehensively manage these patients as they grow in number and their life spans lengthen after diagnosis. He says the goal is to help providers treat the patient and not just the tumour, taking into account the patient’s performance status, life expectancy, burden of systemic disease and available treatment options.
Spratt says, “Most of the frameworks that have been available prior to this have focused on just surgery or just radiation. This algorithm integrates all of the specialties together, including physical medicine and rehabilitation, radiology and medical oncology, to provide a much more personalised treatment approach for patients with metastatic cancer to the spine.”
A different approach
Cancer can spread widely through the body, yet this algorithm specifically focuses on metastases to the spine. Researchers say a metastasis in the spine throws a wrench in typical treatment plans because of the sensitivity of the spinal cord. Quality of life can worsen much faster.
Szerlip further explains: “A spine metastasis causes a lot of pain. People can live with metastases in other areas of the body without much discomfort, but bone pain hurts a lot, and the ability to treat a tumour near the spinal cord is less. Surgeries on other bones are much easier than surgeries on the spine, and less morbid.”
Popular treatment paths address both the neurologic benefit and the oncologic benefit. That might mean a surgical decompression of the tumor, followed by radiation to attempt to control the cancer. Spratt is particularly excited about offering spine stereotactic body radiotherapy (SBRT), a form of high-dose radiation that requires just one to three treatments. Conventional radiation results in only about a 50 percent reduction in pain three months after treatment, and the cancer is eliminated for only a short time. Spratt says spine SBRT is a game changer, showing greater than 90 percent pain reduction and more effectively controlling tumour growth beyond one year post-treatment.
“With this technique, you’ve basically spared the spinal cord so you can give a much higher dose just millimeters away,” he says.
Patients are living longer
Most patients who present with metastatic spine cancer know they have cancer and have had it for some time, Szerlip says. The cancers that most often lead to spine metastasis tend to be renal cell, breast, prostate, sarcoma and lung, the researchers say.
However, not all patients who could benefit from a spine oncology clinic will set foot inside one. Szerlip and Spratt say their algorithm will also raise awareness for doctors who care for people with metastatic spine cancer.
“If you look back 10 or 20 years, you’d see people with spine metastasis lived in the order of months,” Spratt says. “Now, with new systemic therapies, targeted therapies and immunotherapies, it may be years.”
That means there is more opportunity to treat the cancer, to manage the patient’s comfort and to prevent painful and debilitating compression that can result after a period of living with a tumour pressing on your spinal cord.
Szerlip says not long ago, physicians were much less likely to send a spinal metastasis patient to a neurosurgeon because of the high morbidity of surgeries. Now, he says, spine oncology clinics can offer additional options and surgical procedures with less morbidity than in the past. However, these huge surgeries are still highly morbid.
A long-term project
The algorithm that leads to these treatment decisions takes the user through a series of steps starting with an assessment of life expectancy. The systemic burden of the disease is then considered, followed by a calculation of how controlled the disease is, and finally a consideration of systemic treatment options. The algorithm is the result of synthesising the information presented in 243 studies, and a collation of data focusing on what diverse spine oncology clinics’ practices look like.
However, Szerlip says much more data are needed to continue to develop best practices and prove that current efforts are most effective.
“Identifying which patients should get these treatments is also difficult,” he says. The researchers are working with oncologists to help determine who will live long enough to benefit from these procedures.
He says basic science research will be important to continue to develop treatments specifically for spine metastases, because they develop differently than other metastases.
