Cancer Cells Can Drift to the Spine

Source: Life Times

Han Xiuxin, Associate Chief Physician, Department of Bone and Soft Tissue Oncology, Tianjin Medical University Cancer Institute & Hospital

The dreadfulness of malignant tumors lies not only in the invasion of the primary lesion, but also in the fact that cancer cells, akin to "wanderers", can easily "drift" throughout the body via the blood or lymphatic system. Among the numerous destinations, the spine is the most frequent "landing site". Statistics show that approximately 30% to 70% of patients with malignant tumors develop spinal metastasis, and 5% to 10% of these cases progress to spinal cord compression. This not only causes severe pain, but may also lead to paralysis, posing a serious threat to the quality of life.

The high susceptibility of the spine to tumor metastasis is related to its anatomical structure. First, the vertebral bodies of the spine are rich in red bone marrow with slow blood flow, acting as an efficient "filter" that facilitates the retention, implantation and proliferation of cancer cells carried by the blood circulation. Second, there is a vertebral venous plexus around the spine that has no venous valves (allowing bidirectional blood flow) and connects with the pelvic, thoracic and abdominal cavities. When the patient experiences increased abdominal pressure such as during coughing or defecation, cancer cells can directly bypass the pulmonary circulation from primary lesions in organs like the prostate, breast and kidney, and retrogradely reach the spine. The medical "seed and soil" hypothesis also points out that the microenvironment of the spine can secrete a variety of growth factors, acting like fertile soil to specifically attract certain types of cancer cells to settle and grow. Clinically, lung cancer, breast cancer, prostate cancer, kidney cancer and thyroid cancer are the most prone to spinal metastasis.

When cancer cells successfully "set up camp" in the spine, the body will send out distress signals:

Pain: Characterized by nocturnal pain that does not subside with rest or lying flat, mostly presenting as persistent dull pain, soreness, or even intractable pain.

Symptoms of spinal nerve compression: Manifested as numbness and weakness in the limbs, unsteady walking (such as a feeling of stepping on cotton). Severe or rapidly progressing conditions may cause paralysis.

Pathological fracture: A minor external force can cause a pathological vertebral fracture, manifested as sudden severe pain and difficulty walking.

Systemic symptoms: Manifested as weight loss, fatigue, anemia, etc.

At present, the treatment goal for spinal metastatic tumors has shifted from pursuing "radical cure" to "preserving function, controlling pain, improving quality, and prolonging survival". Clinically, a multidisciplinary collaboration model is often adopted, emphasizing the organic combination of systemic treatment and local treatment.

Systemic treatment controls the progression of the primary tumor at its source through means such as chemotherapy, targeted therapy, immunotherapy and endocrine therapy. Anti-osteolytic treatment is also crucial: drugs such as bisphosphonates or denosumab can inhibit bone destruction like "reinforcing city walls" and reduce the risk of fractures. Local treatment delivers precise strikes: radiotherapy (such as stereotactic radiosurgery) can accurately kill tumor cells and quickly relieve pain. Surgery mainly addresses spinal instability and nerve compression, restoring spinal stability through decompression and reconstruction; minimally invasive surgery (such as percutaneous vertebroplasty) can quickly relieve pain; for patients with oligometastasis, en bloc resection can effectively prolong survival. The entire treatment process needs to be coordinated with standardized analgesia, nutritional and psychological support to fully guarantee the patient's quality of life.

Although tumor metastasis cannot be completely prevented, scientific responses by cancer patients can greatly reduce the risk. Specifically, patients should strictly follow medical advice for standardized treatment and regular reexamination; supplement calcium and vitamin D under the guidance of doctors, and use bone-protective drugs when necessary; engage in moderate gentle exercise (such as walking) when physical fitness permits, and avoid long-term bed rest; ensure balanced nutrition, especially increasing the intake of high-quality protein. People with a previous history of malignant tumors or high-risk groups for malignant tumors should seek medical attention promptly once they experience low back pain or neck and shoulder pain that worsens at night and does not subside with rest.

Disclaimer: The information in this article is for popular science reference only and does not constitute medical diagnosis advice.