A reevaluation of bone scans in breast cancer.

A retrospective analysis of 151 patients with breast cancer over 2 years was performed to assess laboratory values as predictors of metastatic disease demonstrated by technetium-99 bone scan. In 105 patients with normal alkaline phosphatase (AP) and lactate dehydrogenase (LDH) values, only one positive bone scan (0.95%) was obtained. If either the AP or LDH value was abnormal, 15 of 29 scans (51.7%) were positive. If both values were abnormal, six of nine patients (66.7%) had positive bone scans. Of 41 patients with either an elevated AP or LDH, 26 (63.4%) were shown to have metastatic breast disease. In our subgroup of 120 consecutive admissions for primary evaluation and treatment of breast cancer, the 95 patients with normal AP and LDH values had 41 negative bone scans and no evidence of distant metastases in any patient. According to these results, we recommend that breast cancer metastatic screening be done by alkaline phosphatase and LDH determinations, and that isotope scans should be reserved for those patients having normal values or symptoms that suggest metastases.