Relationship between Thallium-201 SPECT Mammoscintigraphic Findings and Ki-67 or P-Glycoprotein Expression in Breast Cancers: A Preliminary Report

Received 4/4/2002; accepted 4/26/2002. For correspondence or reprints contact: Chia-Hung Kao, M.D., Department of Nuclear Medicine, China Medical College Hospital, 2 Yuh-Der Road, Taichung 404, Taiwan. Tel: (886)4-22052121 ext. 3475, Fax: (886)4-22023442, E-mail: [email protected] Purpose: The aim of this study was to compare single photon emission computed tomography (SPECT) mammoscintigraphic findings of thallium-201 (Tl) with the expression of Ki-67 and P-glycoprotein (Pgp) in breast cancers. Methods: Twenty-four patients diagnosed with infiltrating ductal breast cancer underwent Tl SPECT mammoscintigraphy before surgery or biopsy to calculate tumor to background (T/B) ratios. Ki-67 and Pgp expressions were measured by immunohistochemical analyses on multiple nonconsecutive sections from surgery or biopsy specimens of breast cancers. Results: The T/B ratios were significantly lower for tumors in 11 patients with positive Ki-67 expression than for those in 13 patients with negative expression (4.26 ± 0.41 vs. 2.25 ± 0.33, P < 0.05). However, differences in T/B ratios of 8 patients with positive Pgp expression (3.52 ± 0.40) and 16 patients with negative Pgp expression (3.42 ± 0.45) were insignificant in this study (P > 0.05). Conclusions: Our results suggest that T/B ratios calculated from Tl SPECT mammoscintigrapy are useful for predicting the presence of Ki-67 expression in breast cancers.