Summary Three hundred and sixty-seven women presenting to the Breast Unit at Guy's Hospital between 1975 and 1990 whose first distant metastasis was in the skeleton were identified and the influence of a number of patient and tumour characteristics on the development and subsequent prognosis of bone metastases was assessed.One hundred and thirty-nine women had disease that remained clinically confined to the skeleton. They were more likely to be older, with lobular carcinoma and to have presented initially with little or no axillary lymph node involvement. The 228 women who subsequently developed disease at extra-osseus sites were more likely to have poorly differentiated ductal tumours and heavy lymph node involvement at primary diagnosis.On multivariate analysis, the clinical and pathological factors of greatest prognostic importance for survival after the development of bone metastases were histological grade (P = < 0.0001), oestrogen receptor status (P = < 0.0001), bone disease at initial presentation (P= < 0.0001), disease-free interval (P= 0.002) and age (P= 0.006).To enable a rational cost-effective use of bisphosphonates in metastatic bone disease, selection of patients with relatively indolent, bone-only disease for bisphosphonate therapy (as defined in this study) should be compared with the current licensed recommendation of unselected treatment for all patients with lytic bone metastases.Bone metastases are frequent in advanced breast cancer and often contribute to the cause of death. Like breast cancer affecting other organs, metastatic bone disease has an extremely variable prognosis. The median survival is 2 years with 20% of patients remaining alive for 5 years after first recurrence in bone (Coleman and Rubens, 1987). In addition, a significant proportion of patients appear clinically to have disease confined to the skeleton, and these women die of the complications of metastatic bone disease, namely immobility, pathological fractures, hypercalcaemia of malignancy and bone marrow failure, with no evidence clinically of involvement at other metastatic sites.With the development of bisphosphonates as specific treatments for metastatic bone disease (Body et al, 1996), there is increased interest in identifying those patients who are most likely to benefit from bisphosphonate treatment. In addition, if prophylactic use of bisphosphonates proves able to influence the development of bone metastases, it will be important to identify those patients at greatest risk of bone involvement, particularly in isolation from other metastatic disease, so that treatment can be targeted rationally. In this study, we have reviewed the clinical and tumour characteristics of patients developing first recurrence of breast cancer in bone and identified prognostic factors that predict for both survival and/or subsequent spread to other metastatic sites.
PATIENTS AND METHODSThree hundred and sixty-seven women presenting to the Breast Unit at Guy's Hospital between 1975 and 1990 whose first distant metastasis was in the s...