25P - Stromal characteristics are potential prognostic markers for ipsilateral locoregional recurrence in ductal carcinoma in situ (DCIS)

Date 08 May 2014
Event IMPAKT 2014
Session Welcome reception and Poster Walk
Topics Breast Cancer
Translational Research
Presenter Mieke Van Bockstal
Citation Annals of Oncology (2014) 25 (suppl_1): i8-i16. 10.1093/annonc/mdu066
Authors M. Van Bockstal1, K. Lambein1, O. De Wever2, M. Praet1, V. Cocquyt3, R. Van Den Broecke4, G. Braems4, H. Denys3, L. Libbrecht1
  • 1Pathology, Gent University Hospital, 9000 - Ghent/BE
  • 2Laboratory Of Experimental Cancer Research, Ghent University, Ghent/BE
  • 3Medical Oncology Dept., Gent University Hospital, Ghent/BE
  • 4Gynaecology, Ghent University Hospital, Ghent/BE

Abstract

Introduction:

Ductal carcinoma in situ (DCIS) is regarded as non-obligate pre-invasive precursor of invasive ductal carcinoma. Up to one in three patients will develop local recurrence after breast-conserving surgery (BCS) alone, but radiotherapy and tamoxifen effectively reduce the incidence of recurrence. Although many attempts have been made to individualize treatment, it is still impossible to select low-risk or high-risk patients with certainty. Recurrence prediction could be improved by identifying additional prognostic markers. As peritumoural stroma actively participates in early breast cancer progression, we explored the prognostic potential of periductal stromal characteristics in DCIS.

Methods:

Histopathological features and hormone receptor/HER2 protein status were analyzed in a first cohort of 65 DCIS with a median follow-up of 112 months. Cox regression analysis was used to determine hazard ratios for all variables in relation to time to recurrence. Immunohistochemical staining of nine stromal proteins was performed in a second cohort of 82 DCIS without available follow-up data, and correlated with stromal architecture. Decorin protein was selected and further analyzed in the first cohort.

Results:

In cohort I, the only histopathological variable significantly related to increased ipsilateral locoregional recurrence was myxoid periductal stromal architecture (p = 0.015). Therefore, stromal architecture was applied as a surrogate outcome marker in cohort II. An immunohistochemical screening of nine stromal proteins showed that reduced stromal decorin expression correlated most strongly with myxoid stroma (p < 0.001). This association was confirmed in cohort I (p < 0.001), and patients with reduced periductal decorin expression were shown to have a higher risk of ipsilateral locoregional recurrence (p = 0.008).

Conclusions:

Periductal myxoid stroma and reduced periductal decorin expression might be prognostic for ipsilateral locoregional recurrence in DCIS. Additional investigations should validate the prognostic power of these promising biomarkers.

Disclosure:

All authors have declared no conflicts of interest.