Diagnostic algorithm, prognostic factors and surgical treatment of metastatic cancer diseases of the long bones and spine

Overview

This review covers the diagnosis, prognosis and surgical treatment of cancer metastases to the long bones and spine. Improved cancer treatment means many patients now live for years with bone metastases. As a result, fractures, spinal cord compression and other skeletal complications have become more common, and surgeons have a wider range of implants and minimally invasive options.

Long bones: diagnosis and prognosis

The authors present a diagnostic algorithm. In patients with known, controlled cancer, the key question is whether the metastasis is solitary or multiple. With multiple metastases, surgery is always palliative and depends on the local fracture risk. Not every impending fracture needs a preventive operation. Biopsy is needed only when another diagnosis is possible or radical surgery is planned. When the primary tumour is unknown, imaging and tests should look for the most common sources, and biopsy should come last, because it weakens the bone. A pathological fracture is treated differently from a traumatic one: it is less urgent, and prognosis should be assessed before choosing the operation. The type of primary tumour is the strongest predictor of survival, followed by general health, visceral metastases and the number of bone lesions.

Long bones: surgery

Surgery is usually not the first treatment. Systemic therapy, radiotherapy and bone-protecting drugs come first. The main aims of surgery are pain relief, preventing or fixing fractures, restoring mobility and improving quality of life. A solitary metastasis from a controlled primary with good prognostic factors can be removed radically, with long survival possible, especially in breast and kidney cancer. Otherwise, durable fixation with minimally invasive techniques is preferred. Endoprostheses are used around the hip and in patients with better prognosis, and cement-augmented nails or plates are used when life expectancy is short.

Spinal metastases

For the spine, stability is assessed with a spinal instability scoring system, and treatment is guided by the NOMS framework (neurological, oncological, mechanical and systemic assessment). Cord compression that takes away the ability to walk calls for urgent decompression. Radioresistant tumours are treated with stereotactic radiotherapy, and unstable lesions need stabilisation, preferably by minimally invasive techniques. Minimally invasive separation surgery followed by radiosurgery gives durable local control with few complications. Patients in poor general condition gain little quality of life from surgery.