Dataset Information

Proposed new clinicopathological surrogate definitions of luminal A and luminal B (HER2-negative) intrinsic breast cancer subtypes.

ABSTRACT:

Introduction

The St Gallen International Expert Consensus on the Primary Therapy of Early Breast Cancer 2013 recognized substantial progress in the pathological characterization of breast cancer subtypes. A useful surrogate definition was developed to distinguish luminal A-like breast cancer from luminal B-like disease based on a combination of estrogen receptor (ER), progesterone receptor (PgR) and Ki-67 status, without a requirement for molecular diagnostics. Differences depend upon the choice of the threshold value for Ki-67 and the requirement for substantial PgR positivity. We aimed to verify the suitability of the new surrogate definitions of luminal subtypes in terms of distant disease control in a large series of patients.

Methods

We studied 9,415 women with a median follow-up of 8.1 years who (1) had ER-positive, human epidermal growth factor receptor 2 (HER2)-negative early breast cancer and (2) had undergone surgery at the European Institute of Oncology between 1994 and 2006. We evaluated distant disease-free survival of patients with "low" (<14%), "intermediate" (14% to 19%) or "high" (?20%) Ki-67 positivity stratified by PgR expression (negative or low versus high). We calculated the cumulative incidence of distant events, considered competing events and performed multivariable analysis adjusted for pathologic tumor stage, pathologic node stage, tumor grade, peritumoral vascular invasion and menopausal status.

Results

Lack of substantial PgR positivity was associated with poorer outcomes only for patients with an intermediate Ki-67 level (P<0.001). The 4,890 patients (51.9%) with low Ki-67 level (any PgR expression level) or with intermediate Ki-67 level but substantial PgR positivity had comparably good outcomes and thus may represent a most advantageous grouping of those with luminal A-like disease.

Conclusions

The updated pathological definition of intrinsic molecular subtypes may maximize the number of patients classified as having the luminal A-like intrinsic subtype of breast cancer and for whom the use of cytotoxic drugs could mostly be avoided.

SUBMITTER: Maisonneuve P

PROVIDER: S-EPMC4095689 | biostudies-literature | 2014 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Proposed new clinicopathological surrogate definitions of luminal A and luminal B (HER2-negative) intrinsic breast cancer subtypes.

Maisonneuve Patrick P Disalvatore Davide D Rotmensz Nicole N Curigliano Giuseppe G Colleoni Marco M Dellapasqua Silvia S Pruneri Giancarlo G Mastropasqua Mauro G MG Luini Alberto A Bassi Fabio F Pagani Gianmatteo G Viale Giuseppe G Goldhirsch Aron A

Breast cancer research : BCR 20140620 3

<h4>Introduction</h4>The St Gallen International Expert Consensus on the Primary Therapy of Early Breast Cancer 2013 recognized substantial progress in the pathological characterization of breast cancer subtypes. A useful surrogate definition was developed to distinguish luminal A-like breast cancer from luminal B-like disease based on a combination of estrogen receptor (ER), progesterone receptor (PgR) and Ki-67 status, without a requirement for molecular diagnostics. Differences depend upon th ...[more]

PMID: 24951027

Similar Datasets

Project description:BackgroundPatients with luminal HER2-negative tumours have a favourable prognosis. However, there is a subpopulation in which poorer outcomes are obtained with endocrine therapy alone. This subpopulation is considered to benefit from chemotherapy. However, the significance of chemotherapy for those with luminal tumours has decreased due to recent changes in treatment strategies. Thus, it is often difficult to determine whether we should recommend chemotherapy to such patients in clinical practice. We investigated Ki67 expression, as a means of predicting the responses of luminal HER2-negative breast cancer patients to neo-adjuvant chemotherapy (NAC), in order to identify a subpopulation that would benefit from these treatments.MethodsWe enrolled 114 luminal HER2-negative breast cancer patients undergoing surgery after NAC. Biomarkers were examined using biopsy specimens obtained prior to treatment, to avoid any chemotherapy-related effects. Chemotherapy effects were determined employing operative specimens and we defined pathological complete response (pCR) as invasive nest disappearance, based only on the primary breast tumour. We applied receiver operating characteristic curve analysis to data from our 114 patients, to investigate Ki67 expression as a predictor of pCR.ResultsThe pCR rate was significantly higher for tumours with high Ki67 expression (p?<?0.01) and all patients who obtained pCR remained recurrence-free during the median 58-month observation period. We identified 35% as the Ki67 cut-off value which distinguishes those with a pCR from other cases. Another dataset, comprised of 196 patients with a median 29-month observation period, was recruited for validation. Disease-free survival was found to be significantly (p?<?0.01) lower in the patients with tumours in which Ki67 expression was higher than 35%.ConclusionOur results raise the possibility of the luminal HER2-negative subpopulation with Ki67 expression higher than 35% benefiting from chemotherapy, as evidenced by improved survival.

Dataset Information

Proposed new clinicopathological surrogate definitions of luminal A and luminal B (HER2-negative) intrinsic breast cancer subtypes.

Introduction

Methods

Results

Conclusions

Publications

Proposed new clinicopathological surrogate definitions of luminal A and luminal B (HER2-negative) intrinsic breast cancer subtypes.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets