Translational breast cancer research in luminal breast cancer

Excerpt

Luminal breast cancer constitutes almost all ER-positive tumours and as such constitutes around 75 to 80% of the disease. The luminal group is highly heterogeneous in terms of genetic aberrations such as mutations, amplifications/deletions and translocations, and also phenotypic characteristics such as proliferation and the expression of oestrogen-dependent proteins such as PgR, TFF1 and GREB1. While assessment of some of these molecular characteristics at presentation can act as a guide to outcome, there remains substantial uncertainty in prognostic and predictive algorithms. Our approach has been to study the biological relationships by applying specific suppressants of the synthesis of oestrogen - that is, aromatase inhibitors (AIs) - in the presurgical setting. The changes in proliferation (Ki67) that occur are related to treatment benefit and the residual Ki67 to residual risk of recurrence. In addition, the molecular changes can be characterized as intermediate endpoints of response. …