Nottingham Prognostic Index (NPI) is a used prognostic model for breast cancer patients, but new histological prognostic factors are today defined. We evaluated their effect within patients with poor prognosis NPI score.
We retrospectively selected 351 non-metastatic breast cancer patients with High NPI score (>5,4). They were classified according to surrogate definition of intrinsic subtypes of breast cancer (St Gallen 2015). Several prognostic factors were evaluated. We used log rank test, cox regression model to evaluate the significance of clinic-pathological factors.
Median age of our population was 50 years. They were luminal A in 30%, Luminal B in 43%, HER overexpression in 10% and basal like in 17%. On univariate analysis, menopausal status (HR = 0,32 [0.13-0,76]), endocrine receptors expression (HR = 6,52 [2,57-16,54]), HER2 expression (HR = 3,08 [0.191-10.39]), Mitotic index (HR = 1,05 [1,02-1,09]) and obesity (HR = 3,49 [1,27-9,58]) were significant prognostic factors. There was no prognostic value of age<35 years, Ki 67 cut-off of 20% and nodal capsule rupture. There was a highly significant difference (p < 0.0001) in overall survival between the 4 intrinsic subtypes. Five-year overall survival was 95% for Luminal A, 90% for Luminal B, 56% for HER2 and 36% for basal-like. On multivariate analysis receptors expression and intrinsic subtype were significantly associated to survival (p < 0.05).
In NPI aggressive disease, the most important prognostic factors were receptors expression and intrinsic subtype. The elaboration of a histology-matched NPI score could afford better prognostic evaluation of early stage breast cancer.
Abderrahmen Mami Hospital, Medical Oncology Department.
Has not received any funding.
All authors have declared no conflicts of interest.