Simultaneous staining of Ki-67 and chromosome 8 in invasive ductal carcinoma: association with prognosis

抄録

Introduction: This study aimed to evaluate an approach that uses simultaneous staining to estimate malignant potential. This approach combines immunofluorescence (IF) staining for Ki-67 expression with fluorescence in situ hybridization (FISH) for copy number aberrations (CNA) of chromosome 8 in breast cancer cells. Methods: In 50 specimens of invasive ductal carcinoma (IDC), we examined a method that simultaneously combined immunostaining (Ki-67) and FISH with a chromosome 8 centromere-specific probe. Breast cancer cells were classified into Group 1, Ki-67 positive and chromosomal aberrant; Group 2, Ki-67 negative and chromosomal aberrant; Group 3, Ki-67 positive and chromosomal wild; Group 4, Ki-67 negative and chromosomal wild. Results: The frequency of Group 1 was significantly associated with nodal metastasis (p<0.05) and patient prognosis (p<0.05); however, it was not associated with age, tumor size, estrogen receptor status, progesterone receptor status, or histological type. Furthermore, Group 1-positive cases showed a significantly worse prognosis, as shown by the Kaplan-Meier method. Conclusions: We successfully stained for Ki-67 expression and CNA of chromosome 8 in breast tumor sections (n=50). This approach indicated that Ki-67-positive cells with aberrant chromosome 8 were associated with malignant potential in IDC.