The significance of occult skeletal metastases, detected by skeletal scintigraphy, in patients with otherwise apparently 'early' mammary carcinoma.

Fifty patients with apparently 'early' mammary carcinoma on clinical, radiological and biochemical grounds had a skeletal scintigram carried out when they first presented. Twelve (24 per cent) of the patients had a positive scintigram. All these patients have developed metastatic disease in the first 5 years following mastectomy, and at least 9 (75 per cent), and probably 10 (83 per cent), have died from mammary carcinoma during this period. This compares with 10 (26 per cent) of the patients with a negative scintigram who have developed recurrent or metastatic disease, of whom 8 (21 per cent) have died from their disease. Five years following mastectomy none of the patients with a positive scintigram was alive and free from disease, compared with 25 (66 per cent) of the patients with a negative scintigram. It would appear that skeletal scintigraphy is the most sensitive method of detecting skeletal metastases and of staging breast carcinoma at the moment. Where practicable, this investigation should be carried out before embarking upon treatment for any particular patient, and this certaily should become part of any clinical trial comparing different therapeutic regimens. However, before some of the newer bone-seeking isotopes are used in this way, further studies are required to determine their false positive rate.