Spinal metastases

What are spinal metastases?

Metastases to the spine are secondary tumors, in other words, daughter tumors that have arisen as part of a cancer disease of another organ and are found in the vertebral bones. Mostly, the vertebral bodies are first affected. Metastases rarely occur at the side of the spinal cord, or behind it in the region of the spinous processes. They can, however, spread to this region of the bone and also to the spinal canal containing the spinal cord. 

There is a distinction made between osteolytic, or bone-degrading, metastases and osteoplastic, or bone-building metastases. Mixed metastases express both osteolytic and osteoplastic components.  

Bone metastases, both spinal and other bones, represent the most common bone tumors in adulthood. Following the liver and lungs, bones are the third most common tissue invaded by metastases. Spinal metastases constitute about 2/3 of bone metastases and occur in about 10% of all carcinoma patients.  

In most cases, spinal metastases are detected in patients of middle age (40-65 years).

How do spinal metastases develop?

Cancer cells can penetrate and multiply in other organs and tissues by breaking through the natural boundaries of cell structures which healthy cells normally cannot escape from. Thereby, they can either enter blood or lymph vessels and travel through them to distant organs, or directly infiltrate neighboring tissues.  

Basically, any late-stage cancer can be accompanied by spinal metastases. But the five most common primary tumors collectively cause up to 80% of vertebral metastases. These include: 

• Breast cancer (mammary carcinoma) 
• Prostate carcinoma 
• Bronchial carcinoma 
• Renal cell carcinoma 
• Thyroid carcinoma

How are spinal metastases noticed?

The breakdown of bone material by osteolytic metastases results in a reduced stability of the bone, so that fractures (broken bones) can easily happen either due to accidents which a healthy bone would withstand without damage, so called minor traumas, or even spontaneously for no apparent reason. 

In the case of osteoplastic metastases, extra tumorous bone tissue is formed, so that stability is usually preserved. Nevertheless, the tumor mass can irritate and damage adjacent nerves or may even damage the spinal cord that runs through the spinal canal as a result of the growth that displaces it. Pain is a frequent consequence, as well as different neurological deficits. Both motor function and sensitivity or vegetative functions such as bowel and bladder function can be reversibly or irreversibly disrupted.

What is the treatment for spinal metastases?

If a patient with no previous tumor disease is diagnosed with spinal metastases, the first priority is to search for the primary tumor. A comprehensive medical history and physical examination may yield hints as to the location of the tumor. Screening examinations such as computed tomography of the chest and abdominal-pelvic region, ultrasound examinations and gastroscopy or colonoscopy are also carried out, the order of which depends on the likelihood, and will continue until the primary tumor can be visualized. 

If the primary tumor is not found, this is known as CUP (cancer of unknown primary). In such cases, a biopsy of the metastasis can be taken from the vertebral bone and studied histologically, and immunohistochemically, in order to determine the nature of the primary tumor. 

To localize or exclude other bone metastases, a skeletal scintigraphy is taken. This involves injecting a tracer substance into a vein, which will accumulate in bones depending on the blood flow and bone cell activity. Subsequently, a gamma camera is used to obtain images of the entire body, showing areas of particularly high accumulation around bone metastases. 

Multimodal therapy options are available for treating bone metastases. Nevertheless, it is important to consider the prognosis of the underlying disease in all treatment decisions. For curable patients, more radical treatment is justified, while for non-curable cancer, improving the quality of life through adequate pain management and preservation or restoration of neurological function is the main goal. 

The following therapy approaches are used for spinal metastases:

Drug therapy 

Medications used to treat spinal metastases include pain medication as needed, as well as bisphosphonates, a drug that inhibits the breakdown of bone tissue and is appropriate for osteolytic, as well as mixed metastases. Additionally, cancer as well as metastases can be treated with chemotherapeutic drugs and, if the cancer is hormone-sensitive, with hormone therapy. 

Radiotherapy 

Radiation can be applied to shrink metastases, and thereby reduce the symptoms provoked by them. 

Surgical therapy 

Depending on the type of primary tumor, a resection with curative intent can be carried out for single metastases. Even with palliative therapeutic intent, resection may be appropriate, for instance if neurological damage is likely to occur. Osteosyntheses, the stiffening of joints for stabilization, and the surgical treatment of fractures are also included in the surgical therapy of spinal metastases.

What about life expectancy and prognosis for spinal metastases?

On average, the two-year survival rate for existing spinal metastases ranges from 10 to 20%. It is highly dependent, however, on the primary tumor type and how invasive the therapy is. For instance, the two-year survival rate associated with spinal metastases from breast or prostate carcinoma is 44%, and 9% from bronchial carcinoma. 

Patients with spinal metastases develop narrowing of the spinal cord due to the metastases in 10% to 20% of cases.

Which doctors and clinics specialize in spinal metastases? 

Spinal metastases represent an interdisciplinary condition. Depending on the therapy regimen, doctors from different fields are involved. Among them are oncology, neurosurgery, radiology and radiotherapy, and depending on the tumor type, other specialties, such as gynecology in the case of breast carcinoma, or urology in the case of prostate carcinoma.

If you're in need of a doctor, you expect the best medical care possible. So of course patients are curious to find out what clinic to go to. As there is no objective way to answer this question and a legitimate doctor would never claim to be the best, patients must rely on a doctor's experience.

Let us help you find an expert for your condition. All listed doctors and clinics have been reviewed by us for their outstanding specialization in the field of spinal metastases and are looking forward to your inquiry or wish for treatment.

Sources:

• The Treatment of Spinal Metastases, Delank, Karl-Stefan; Wendtner, Clemens; Eich, Hans Theodor; Eysel, Peer, Dtsch Arztebl Int 2011; 108(5): 71-80; DOI: 10.3238/arztebl.2011.0071  
• flexikon.doccheck.com/de/Knochenmetastase  
• neurochirurgie.insel.ch/erkrankungen-spezialgebiete/wirbelsaeule/wirbelmetastasen