Metastatic bone disease

Abstract

Aim: To evaluate epidemiology, prognosis and diagnostics in metastatic bone disease and identify risk factors for failure after operation for pathologic fracture.

Patients: The study was based on patients treated for skeletal metastases, myeloma or lymphoma between 1986 and 1998 at the Oncology Service, Department of Orthopedics, Karolinska Hospital and on patients diagnosed with symptomatic skeletal metastases 1989-1994 in the Stockholm Region.

Epidemiology: 641 breast cancer patients were diagnosed with symptomatic skeletal metastases 1989-1994. Based upon 1100 new primary breast cancer cases yearly, the overall risk of developing symptomatic skeletal metastases was 10-15%. One out of 5 patients with skeletal metastases required surgical treatment for skeletal complications.

Prognosis: The survival rate after surgical treatment for skeletal complications was 0.3 at 1 year and 0.008 at 3 years. Multivariate analysis based on 619 patients showed that complete pathologic fracture and soft tissue metastases were negative prognostic variables for 1-year survival after operation. Solitary skeletal metastasis, breast, prostate, kidney cancer, myeloma and lymphoma were positive variables. Immunohistochemistry was used to analyze ER, PgR, MIB and p53 in 43 primary breast carcinomas and their skeletal metastases. PgR and p53 may provide prognostic information after pathologic fracture and not only at diagnosis of the primary tumor.

Diagnosis: Fine Needle Aspiration Biopsy ((FNAB) was assessed in 110 patients for diagnostic accuracy and to which extent information about primary site of the metastatic carcinoma could be gained. There were 80 patients with metastatic carcinoma, 14 with lymphoma, and 16 with myeloma. FNAB offered correct diagnosis in 9 of 10 patients an also provided guidance in the search for the primary lesions. Hence, 27 of 30 myeloma or lymphomas were diagnosed by FNAB and in half of the patients with metastatic carcinoma the site of the primary tumor could be ascertained. For patients with a suspected skeletal metastasis the search for the primary tumor may preferably start with FNAB.

Surgical treatment: Risk factors for failure after operation for pathologic fractures were identified in 192 patients treated for 228 metastatic lesions of the long bones. 26 out of 22 procedures (11 %) lead to failures necessitating reoperation. Long survival after surgery was the most important risk factor for failure of the reconstruction. Kidney cancer was the primary tumor associated with the highest rate of reoperations. Reconstructions based on prosthetic a opposed to osteosynthetic devices appeared safer. There was a tendency for a high reoperation rate in hospitals with few treated patients.

Conclusion: To decrease the risk of reoperation, it is important to identify patients with a long expected survival. In patients with a good prognosis, wide resection and reconstruction as applied in primary malignant bone tumors should be considered.