Prognostic and predictive value of TFF1 for adjuvant endocrine therapy in Chinese women with early ER positive breast cancer: comparing aromatase inhibitors with tamoxifen.

Factors that predict in favor of an aromatase inhibitors (AIs) over tamoxifen (TAM) in estrogen receptor (ER) breast cancer remains to be identified. We compared progesterone receptor (PR) and trefoil factor 1 (TTF1) status (+ve versus -ve) as predictive of superior effect of AI's over tamoxifen among a total of 1973 Chinese women with early ER+ breast cancer. The expression of TFF1 was independently associated with ER and PR. However, there was no correlation with TFF1 and HER-2 expression. Treatment effect was more pronounced in the ER+/TFF1+ postmenopausal patients with a hazard ratio favoring AIs (HR = 0.397, 95%CI 0.183-0.860), but not in the PR positive cohorts (HR = 0.466, 95%CI 0.186-1.164). We suggested that AIs was better than TAM especially in the postmenopausal patients with ER+/TFF1+ breast cancer; however the clinical application of this observation still requires further prospective studies.