Metastatic disease has to be treated with four components in mind; pain must be controlled, fractures must be prevented and treated, patient independence must be maintained and tumor progression must be prevented (Jacofsky, 2004, p. 27). Pain is due to the tumor biology and structural insufficiency of bone due to destruction. Bone pain without structural insufficiency is treated with narcotic analgesics and radiation therapy or external beam radiation. Hormonal therapy is useful for prostate cancer metastases. Biophosphonates improve pain and reconstitute bone stock.
They also reduce tumor cells by inducing apoptosis (Jacofsky, 2004, p. 27) Impending fractures may be treated with surgery to prevent the risk of fractures. The decision to perform surgery must be taken by considering the amount of bone destruction. The surgical stabilization is fairly effective in that there is resolution of the pain. Mobility and independence are also improved. Weightbearing pain is a predictor of fractures (Jacofsky, 2004, p. 27). Serial radiographs help to monitor the progression of the disease. Surgical options using
plates, intramedullary devices and prosthetics may be indicated. Metaphyseal and epiphyseal may be done if enough bone stock is present and an intact articular surface is present, with plates augmented by methyl methacrylate (Jacofsky, 2004, p. 27). One intact cortex is needed for fixation and weight bearing when plates are used. Large destructive lesions require a prosthetic replacement. Pre-operative tumor remobilization is a useful adjunct procedure in metastatic disease. Renal metastasis and myelomas are highly vascular and have a tendency to bleed profusely intraoperatively and cause death.
Remobilization helps to reduce blood loss in 90% of cases during surgery. It also reduces pain where surgery is not indicated (Jacofsky, 2004, p. 28). Prophylactic fixation for patients at-risk for fractures, post operative external beam irradiation is useful. 15% of those who had only the prophylactic surgery needed a repeat surgery after losing fixation and had severe pain consequently. 3 % only of those who had both initially required repeat surgery. Radiation is done 2-4 weeks after fixation. Dose is 20-30Gy n 5-10 fractions (Jacofsky, 2004, p. 28).
If life expectancy is more than 12 months, a higher dosage is applied. Prognosis Patients with bony metastasis finally succumb to the illness. In a patient who had recommended treatment, the period of survival varies from 6 to 48 months and is difficult to predict. The survival period for bony metastases due to thyroid carcinoma is 48 months, prostate cancer 40 months, breast cancer 24 months and 6 months for lung cancer, melanoma and kidney cancer (Jacofsky, 2004, p. 28). However a person who had a 2-year disease-free interval when he had no visceral disease and a non axial metastasis, may live for years.
If the patient refuses treatment, the end is faster, due to a rapid dissemination of the secondaries of the primary cancer without any control to other parts especially the bone. Survival may be only for 3-6 months. References: Berruti A,Dogliotti L et al (2002) “Metabolic effects of single-dose pamidronate administration in prostate cancer patients with bone metastases. Int J Biol Markers 17: 244–52. American Cancer Society. Cancer Facts & Figures 2008. Atlanta: American Cancer Society; 2008. Clines, G. A. , Chirwin, J. M. and Guise, T. A. (2005). “Skeletal Complications of Malignancy:
Central Role for the Osteoclast” Chapter 9 in the Volume Two Topics of Bone biology In (Eds. ) Bone Resorption by Felix Bronner and Mary C. Farach-Carson, Published by Springer in 2005 DeBois, J. M. (2002). “TxNxM1 :The Anatomy and Clinics of Metastatic Cancer”. Published by Springer Netherlands. Fontana A, Delmas PD. (2000) “Markers of bone turnover in bone metastases. Cancer 88 (12 Suppl): 2952–60. Guise TA and Mundy GR. (1998) “Cancer and bone” . Endocr Rev 19:18–54. Jacofsky, D. J. , Frassica, D. A. and Frassica, F. J. (2004). “Metastatic Disease to Bone”.
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