Prognostic value of semi-quantitative tumor uptake on Tc-99m sestamibi breast-specific gamma imaging in invasive ductal breast cancer

Objectives: This study investigated the prognostic value of preoperative breast-specific gamma imaging (BSGI) uptake measured by a semi-quantitative method in invasive ductal carcinoma (IDC). Methods: One hundred and sixty-two women with IDC who underwent preoperative BSGI were retrospectively enrolled. The tumor-to-normal tissue ratio (TNR) was measured on BSGI and correlated with histologic prognostic factors. The prognostic impact of TNR was tested with regard to progression-free survival (PFS) and compared with established prognostic factors. Results: High TNR was significantly correlated with tumor size >2 cm (p < 0.001), high nuclear grade (p = 0.04), high histologic grade (p = 0.01), axillary node positivity (p = 0.04), ER negativity (p = 0.03), HER2 positivity (p = 0.01), and high MIB-1 index (p = 0.001). Among 162 patients, 14 experienced recurrence during mean follow-up time of 34.7 ± 14.9 months. In Kaplan–Meier survival analyses, high TNR (p < 0.001), high nuclear grade (p = 0.02), high histologic grade (p = 0.007), ER/PR negativity (p = 0.003 and p < 0.001, respectively), HER2 positivity (p = 0.01), triple negativity (p = 0.02), and high MIB-1 index (p = 0.02) showed a significant relationship with poor prognosis. Among them, high TNR was an independent poor prognostic factor in a multivariate regression analysis (p = 0.01). Conclusions: High BSGI uptake measured by a semi-quantitative method was correlated with diverse poor histologic prognostic factors and was an independent poor prognostic factor in invasive ductal cancer.