Analysis of serial radionuclide bone images in osteosarcoma and breast carcinoma

The authors first describe and illustrate didactically the use of the Kaplan-Meier actuarial technique for serial diagnostic studies. They then present an analysis of previously published data on the results of serial radionuclide bone images in patients with osteosarcoma or breast carcinoma, using this technique. The data indicate that patients with osteosarcoma show an almost linear increase in the occurrence of bone metastases between 5 and 29 months after diagnosis; the rate is approximately 1% per month. Patients with breast cancer, on the other hand, show a biphasic rate of development, averaging only 0.5% per month during the first year after diagnosis but increasing rapidly to approximately 2% per month after 15 months.