Clinical Significance of Solitary Costal Hot Spot on Postoperative Bone Scan in Patients with Breast Cancer

摘要

Purpose Bone is the most common site of metastasis from breast cancer. An abnormal bone scanfinding, however, is not specific in differentiation of bone metastasis from traumatic or inflammatory bone diseases. The purpose of this study was to identify clinical findings that could help evaluate the etiology of solitary costal hot spots on a bone scan. Methods The study included 32 patients(all women, mean age 51±1 years) showing solitary costal hot spots on postoperative bone scans performed between January 1998 and December 2002. In order to classify the etiology of solitary costal hot spots as non-malignant or malignant, all available clinical, scintigraphic, laboratory and other radiographic examinations were taken into consideration. Results The mean follow-up period was 42.5 months. Among 32 hot spots, 7(21.8%) were metastatic, and the remaining 25 (78.2%) non-malignant. The mean period of first detection after operation was 17.0±16.3 months in the metastatic and 26.0±21.3 months in the non-malignant groups. The metastatic group was significantly associated with advanced breast cancer. In the localization of rib lesion, 20(62.5%) of the solitary costal hot spots were in the anterior arc, 5(15.6%) in the lateral arc and 7(21.9%) in the posterior arc. In the group with a location at the anterior arc, 16 (80%) were non-malignant, whereas 4(20%) were malignant. In those localized at the anterior arc, 12(60%) were on ipsilateral and 8(28%) were on contralateral. The difference between the hot spots in the ipsilateral and contralateral locations was not significant. The carcinoembryonic antigen (CEA) and CA15-3 were elevated : in 5 (51%) and 3 (43%) patients with metastatic spots, and in 4 (16%) and 1 (4%) patient with non-malignant lesions, which were significantly different. Conclusion It was found that an advanced state of primary breast cancer and the increase of tumor markers (CEA and CA15-3) were the significant factors for the direction of the nature of solitary costal hot spots on postoperative bone scans in patients with breast cancer.