Correlation between uptake of Tc-99m SestaMIBI and prognostic factors of breast cancer

The purpose of this retrospective study was assessment of correlation betwe en Tc-99m sestaMIBI uptake and some prognostic factors of breast cancer The following prognostic factors have been included in this study: size of the tumour, age of the patients, axilla node invovlvement, oestrogen and proge sterone receptor (ER, PR) status, grading system of Bloom-Richardson and Ki -67 antigen expression. Methods: 79 patients were enrolled in this study, w ith 85 lesions confirmed as primary breast cancers. Mean age of patients wa s 53 years. Scintimammography (SMM) was performed after intravenous injecti on of 740MBq. At 5-10 min after injection standard planar images were obtai ned in prone lateral and anterior supine views. Assessment of correlation b etween known prognostic factors of breast cancer and uptake of MIBI (evalua ted as a tumour to background ratio-TBR) was performed used non-parametric (Kendall-tau correlation) statistical analysis. Results: There were 85 brea st cancers (73 invasive ductal carcinomas, 11 DCIS (ductal carcinoma in sit u) and 1 lobular carcinoma. There was positive correlation between TBR Tc-9 9m MIBI uptake and size of the tumour (t=0.19, p=0.01), presence of axilla node invovlvement (t=0.2, p=0.006) and also grade of the IDC tumours evalua ted using Bloom-Richardson's criteria (t=0.18, 0.03). There were negative c orrelation between TBR and presence of PR (t=-0.16, p=0.02) and borderline negative correlation between TBR and age of patients (t=-0.137, p=0.06) and also TBR and ER status (t=-0.135, p=0.065). Patients who are younger and/o r have PR or ER negative cancers have higher Tc-99m MIBI uptake. Patients w ho presented with high grade of malignancy (B-R) also have higher uptake of radiotracer. Also those with higher uptake of radiotracer often had axilla ry node involvement. This would suggest that more aggressive rumours have h igher uptake of Tc-99m MIBI. Finally this study suggest correlation between in vivo uptake of MIBI and some of the known prognostic factors of breast cancer.