The clinical use of staging bone scan in patients with breast carcinoma: Reevaluation by the 2003 American Joint Committee on Cancer staging system

BACKGROUND. Using the new 2003 American Joint Committee on Cancer (AJCC) staging system, the authors evaluated the usefulness of the staging bone scan in patients with primary breast carcinoma. METHODS. The authors examined 1939 patients with primary breast carcinoma for staging bone scan who were treated at a single institution. Pathologic stage was assigned retrospectively according to the 1988 and the 2003 AJCC staging systems. RESULTS. Bone metastasis rates were 0.7% (4 of 586) for patients with Stage I disease, 0.7% (5 of 699) for patients with Stage IIA disease, 2.1% (10 of 479) for patients with Stage IIB disease, 4.5% (7 of 154) for patients with Stage IIIA disease, and 10.5% (2 of 19) for patients with Stage IIIB disease according to the 1988 AJCC staging system. The authors found a significant difference in the bone metastasis rate between patients with Stages IIA and IIB disease in the 1988 staging system (P = 0.039). Reevaluating the patients by the 2003 system resulted in significant upstaging, especially for patients with Stage II/III disease. According to the 2003 staging system, bone metastasis rates were 0.7% (4 of 586) for patients with Stage I disease, 0.6% (4 of 648) for patients with Stage IIA disease, 0.6% (2 of 310) for patients with Stage IIB disease, 4.0% (9 of 225) for patients with Stage IIIA disease, 16.7% (2 of 12) for patients with Stage IIIB disease, and 4.4% (7 of 158) for patients with Stage IIIC disease. It was noteworthy that there was a significant difference between Stages IIB and IIIA in the 2003 staging system (P = 0.010). CONCLUSIONS. Stage reclassification using the new AJCC staging system resulted in upstaging of high-risk patients, as well as a significant decrease in the bone metastasis rate in patients with Stage IIB breast carcinoma. Considering the cost-effectiveness of staging bone scan, the data suggested that it was of little value for patients with Stage I and II breast carcinoma, but was highly recommended for patients with worse than Stage III disease by the new 2003 staging system.