[Skeletal scintigraphy in the follow-up of breast cancer. Statistical and epidemiological viewpoints]

As shown by model calculations skeletal scintigraphy in the follow-up of mammary carcinoma results in an expected predictive value of a positive scan in asymptomatic patients of 6.6%, assuming a sensitivity of 100%, a specificity of 95% and a 5-year disease-free survival rate of 55%. Divided according to clinical stages I-III, the values are 2.1% for stage I, 5.8% for stage II, and 10.7% for stage III. From a statistical and epidemiological point of view, therefore, bone scans are of questionable value in the follow-up of mammary carcinoma, at least in the favourable stages. Scientific assessment of the ever-widening range of follow-up activities is of crucial importance; for this general demand skeletal scintigraphy in mammary carcinoma is but an example.