29P - A negative progesterone receptor in luminal HER-2 negative breast cancer by age at diagnosis: 10 years follow-up
|Date||08 May 2014|
|Session||Welcome reception and Poster Walk|
|Citation||Annals of Oncology (2014) 25 (suppl_1): i8-i16. 10.1093/annonc/mdu066|
S. Olbrecht1, K. Van Asten2, A. Laenen3, C. Remmerie4, H. Wildiers5, G. Floris6, M.R. Christiaens7, I. Vergote8, P. Neven8
An absent progesterone receptor (PR) predicts distant metastases (DM) in ER-pos HER2 neg invasive breast cancer patients (BCP). It is unknown if PR remains prognostic in younger BCP (Yamamoto et al. JCO 2013). We investigated the prognostic effect of PR on DM free interval (DMFI) and BC specific survival (BCSS) by age at diagnosis.
Patients and methods:
Retrospective data of consecutive primary operable ER pos HER2 neg BCP (1/1/2000 - 1/6/2005 ) retrieved from our prospectively managed database. BCP with missing values for PR and/or lost to follow-up (FU) were excluded. Adjuvant radio- and systemic therapy were as indicated by our in-house protocol. A multivariable (MV) competing risk model for DMFI and BCSS was established considering age at diagnosis (age ≤ 50 yrs vs > 50 yrs), PR status (pos if >1% of cells stained with IHC), tumor grade (1–3), tumor size (mm) and lymph node status (neg/pos). Differential prognostic effects of these variables according to PR or age were tested by means of interaction effects. The MV model included significant interactions.
We included 1703 BCP (median FU 10.9 yrs); 1468 (86.20%) PR-pos [486(28.54%) ≤ 50 yrs and 982 (57.65%) > 50 yrs] and 235 PR-neg [49(2.88%) ≤ 50 yrs and 186 (10.9%) > 50 yrs]. In absolute numbers and compared to PR-pos BCP, PR-neg BCP > 50 yrs (15.9% of cases) had more DM (not if grade 1–2) and BCSS. This differed in BCP ≤ 50 yrs but only 9.1% were PR-neg . Results from the MV models showed no effect of PR on DMFI. For BCSS, the effect of PR significantly interacts with age (p = 0.02) resulting in a trend towards decreased risk for PR negative BCP ≤ 50 yrs (HR 0.88; 95% CI 0.45-1.70) whereas a trend for increased risk is observed for PR negative BCP >50 yrs (HR 1.67; 95% CI 0.77-3.59). Table 29P:
Percentage of patients with DM or BCSS according to age, PR, grade and lymph node status (pN).
|Age||≤ 50||> 50||≤ 50||>50|
|PR||PR +||PR-||PR +||PR-||PR +||PR-||PR +||PR-|
A differential prognostic effect of a negative PR on DM and BCSS by age at diagnosis is clinically observed but not maintained after correction for other tumor characteristics. Validation in a larger cohort would be needed to confirm our results.
All authors have declared no conflicts of interest.