Insight opinion to surgically treated metastatic bone disease: Scandinavian Sarcoma Group Skeletal Metastasis Registry report of 1195 operated skeletal metastasis

Abstract

The number of cancer patients living with metastatic disease is growing. The increased survival has led to an increase in the number of cancer-induced complications, such as pathologic fractures due to bone metastases. Surgery is most commonly needed for mechanical complications, such as fractures and intractable pain. We determined survival, disease free interval and complications in surgically treated bone metastasis. Data were collected from the Scandinavian Skeletal Metastasis Registry for patients with extremity skeletal metastases surgically treated at eight major Scandinavian referral centres between 1999 and 2009 covering a total of 1195 skeletal metastases in 1107 patients. Primary breast, prostate, renal, lung, and myeloma tumors make up 78% of the tumors. Number of complications is tolerable and is affected by methods of surgery as well as preoperative radiation therapy. Overall 1-year patient survival was 36%; however, mean survival was influenced by the primary tumor type and the presence of additional visceral metastases. Patients with impending fracture had more systemic complications than those with complete fracture. Although surgery is usually only a palliative treatment, patients can survive for years after surgery. We developed a simple, useful and reliable scoring system to predict survival among these patients. This scoring system gives good aid in predicting the prognosis when selecting the surgical method. While it is important to avoid unnecessary operations, operating when necessary can provide benefit.

Introduction

The burden of cancer is increasing in welfare states. In the Nordic countries, the prevalence of cancer has grown steadily over recent years to about 100 cases per 100,000 persons annually. The cancer mortality rate has remained almost the same over the last 10 years, with an increase of only 2% (58 130 in 1999 vs. 59 440 in 2008) while the incidence of cancer has increased 18% (110 629 in 1999 vs. 130 455 in 2008) [1]. Although the treatment of different primary cancers has become very specialized and effective, the disease will eventually disseminate in some patients. Metastasis results from the spread of tumour cells from their site of origin to other organs. The organ distribution of metastases depends on the type and location of the primary tumour and the route of dissemination of metastatic cells; for example, breast and prostate cancer often metastasize to bone [2]. As treatment options for patients with metastases have improved, the number of patients living with disease is growing, which has led to an increase in cancer-induced complications, such as skeletal-related events like pain, pathologic fractures, hypercalcaemia, anaemia, and paraparesis [3].

Destruction of bone by metastatic disease reduces its load-bearing capabilities and results initially in microfractures. Microfractures can cause pain and eventually lead to a complete fracture of the bone. Some bone metastases are painless, but most bone lesions develop symptoms such as load-related pain or pain at rest [4]. Surgery is most commonly needed for mechanical complications, such as impending or existing fracture, or intractable pain [5]. The main advantages of surgery are immediate pain relief, restored function with possible full weight-bearing, and unlimited range of motion, which can help the patient with activities of daily living.

Bone metastasis indicates that the malignant process is incurable. Survival with metastasized cancer has increased and continues to increase especially in some patients, and therefore data about long-term survivors is needed. In oncologic orthopaedics, the choice of surgical treatment varies between prophylactic intramedullary nailing to massive resection prosthesis. The method of choice depends on the site of metastasis and patient survival. The value and predictability of survival in patients with pathologic fractures in the extremities has increased with the number of case studies reported.

The purpose of this study was to evaluate 1195 surgically treated bone metastases to better understand the relationship between primary diagnosis, location of bone metastases and history of cancer disease with survival, disease free interval and complications after surgery and making a simple prognostic scale for survival after operation of skeletal metastases.