BIOLOGICAL MARKERS OF PROGNOSTIC IMPORTANCE IN BREAST PHYLLODES TUMOURS

Abstract

Phyllodes tumours are uncommon fibroepithelial neoplasms of the breast accounting for less than 1% of primary breast tumours. They are classified into benign, borderline and malignant tumours by WHO, based on five histological parameters ? stromal cellularity, stromal atypia, stromal mitoses, presence of stromal overgrowth, and nature of the tumour border. This diagnostic framework remains challenging due to interpretive subjectivity and variable combinational permutations of histological criteria, leading to difficulties in accurate prediction of biological behaviour. In this study, the prognostic importance of clinicopathological parameters and biological markers were investigated. A predictive nomogram estimating recurrence-free survival in phyllodes tumours patients was constructed. Through genome-wide copy number analyses of prognostically distinct groups, chromosomal aberrations were found to be higher in phyllodes tumours which recurred/metastasized, with high-level amplifications and homozygous deletions detected exclusively in these cases. Finally, prognostic importance of CD117, Six1 and Pax3 was evaluated and discussed.