METATSTATIC BONE DISEASE
Maxime Coles, MD, FICS, FRCS, FAANOS
Orthopedist and Traumatologist, 2011
Metastasis means spread of Cancer to any organ or tissue in the body. The cancerous cells break away from the primary tumor and invade the bloodstream or the lymphatic system. It is estimated that 1.2 million of new Cancer cases are discovered each year. Many theories tried to explain the formation of a Metastasis.
Sir James Paget in 1889 was the first one to bring a ”Seed and Soil” theory spreading the cells through the bloodstream and explaining the new formation of the same tumoral cells at a different location. The pathologist James Ewing explained differently the colonization through the blood flow until Oscar Batson implicated the venous system of the spine to explain the spread to the spine from the prostate gland. Others think that a “Direct Invasion” theory is possible by erosion of a cuta- neous and cancerous lesion like a Melanoma or a Squamous cell carcinoma eroding deeply to the bone.
The skeletal system is considered the largest organ of the body and as such, it becomes a primer target for metastasis. Lesions metastizing distal to the knees and elbows are called acrometastasis and are often seen in the terminal phase.
Few skeletal lesions require surgical intervention unless they become enlarged or permeative. Radiation and Chemotherapy, Hormonal therapy …etc …often provide the first line of treatment for symptomatic relief but when they fail to help, Surgical treatment can be offered when feasible.
The goal of the Orthopedic Surgeon in treating metastatic lesions is to alleviate pain, improve function and ambulation rendering easier medical and nursing care as well as improving the Psychological well being. If surgical treatment is contemplated, it must envision a post operative patient with immediate weight bearing. One should avoid any risky procedures. 50% of all metastatic lesions derive from Carcinomas (Breast, Lungs, Prostate), Lymphoma, Myeloma followed by kidney, thyroid, Genito-Urinary and Gastro-Instestinal tumors. The most common symptom of a metastasis is a localized pain awaking the patient at night, impairing his ability to bear weight on the extremity but if the spine is involved, often radicular or myelopatic symp- toms will be present.
The type of metastasis will dictate the kind of treatment. Often diffused metastasis to the spine will pose a challenge to the spine surgeon necessitating a combination of debulking Intra lesional excision with spinal instrumentation to relieve radicular symptoms. The lesions of the long bone are common and often require intramedullary fixation supplemented by Ce- ment Polymethacrylate after resection or cure- tage of the lesion, Prosthesis and even Am- putation.
1- Martin Malawer, Treatment of metastatic Bone
Disease, Chapter 11, 2001: pp215-230
2-NCCN Clinical Practice Guidelines in Oncology, Bone Cancer, www.nccn.org
3-Jemal A, Siegel R, Ward E et AL, Cancer Statistics,
2008. CA Cancer J Clin, 2008 ;(2):71-96
4- Rougraff RK, Kneisl JS, Simon MA., Skeletal Metastases of unknown origin. A prospective study of a diagnostic strategy. J Bone Joint Surg Am
Info CHIR, M. Coles, No 2, p. 7, 2011