Expression of drug resistance protein related to Tc-99m MIBI breast imaging

Adjuvant and neoadjuvant chemotherapy is increasingly being used in the treatment of breast cancer patients. However drug resistance plays an important role in chemotherapy failure in this cancer. The aim of this study was to determine the correlation between technetium-99m sestamibi (Tc-99m MIBI) breast imaging results and expression of the drug resistance proteins (p-glycoprotein (Pgp), Ki-67 and mutant p53) in human breast cancer tissues. Twenty-four breast cancer patients underwent Tc-99m MIBI breast imaging before surgery or biopsy. Protein expression was investigated by immunohistochemical studies on multiple nonconsecutive sections of surgery or biopsy samples. Tumor to background (TIB) ratios calculated by Tc-99m MIBI breast imaging were correlated with protein expression determined by immunohistochemical studies The TIE ratios were significantly lower in 8 patients with positive Pgp expression (Group I) when compared with 16 patients with negative Pgp expression (Group 2) (1.40 +/- 0.11 and 276 a 0.60 p < 0.05). However, the differences of TIE ratios between the patients with positive and negative Ki-67 mutant p53 expression were not significant. Our data confirmed that Tc-99m MIBI breast imaging is useful for determination of the presence of Pgp expression in breast cancer patients No significant relationship between Tc-99m MIBI breast imaging results and Ki67/mutant p53 was found.