as an Adjunct Prognostic Factor in Breast Cancer Patients with Less Aggressive Disease: A Study with a Review of the Literature.

Background: GATA binding protein 3 () expression is positively correlated with estrogen receptor (ER) expression, but its prognostic value as an independent factor remains unclear. Thus, we undertook the current study to evaluate the expression of and its prognostic value in a large series of breast carcinomas (BCs) with long-term follow-up.

Methods: A total of 702 consecutive primary invasive BCs resected between 1989 and 1993 in our institution were arranged in tissue microarrays, immunostained for ER, progesterone receptor (PR), ki-67, HER2, p53, and , and scored. Clinico-pathological data were retrospectively collected.

Results: was evaluable in 608 (87%) of the 702 cases; it was positive in 413 (68%) cases and negative in 195 (32%) cases. positivity was significantly associated with lower grade ( < 0.0001), size ( = 0.0463), stage ( = 0.0049), ER+ ( < 0.0001), PR+ ( < 0.0001), HER2- ( = 0.0175), and p53 wild-type pattern ( < 0.0001). The median follow-up was 183 months, positivity was associated with better overall survival (HR 0.70, = 0.001), and its prognostic value was retained in a multivariate analysis. The association with better overall survival was stronger in patients with grade 1-2, pT1-2, pN0, stage I-II, ER+, PR+, ki-67 < 20%, HER2-, a wild-type p53 immunohistochemical pattern, and in luminal B BC.

Conclusions: Our findings indicate that is a positive prognostic marker in BC patients, especially in patients with biologically less aggressive BC. Incorporating immunohistochemistry into routine practice could help further stratify BC patients for their risk.