Abstract P2-13-06: Flat epithelial atypia on core biopsy and upgrade to cancer: A systematic review and meta-analysis
Authors: Rudin Anatoliy V , Tanya Hoskin L , Farrell Ann M , Degnim Amy C 
Published: May 2015

Abstract
BACKGROUND: Flat epithelial atypia (FEA) is a recently described breast lesion that may coexist with cancer or atypical ductal hyperplasia (ADH). Currently, there is no consensus on whether to surgically excise FEA diagnosed by core needle biopsy. Our aim was to perform a systematic review and meta-analysis of pertinent studies to determine the frequency of upgrade to cancer or ADH at surgical excision of "pure" FEA (no other high risk lesion on core biopsy).
METHODS: A retrospective search was performed using MEDLINE, Embase, Scopus and Web of Science databases from 1/2003- 4/2014 to capture studies on core biopsy diagnosed FEA followed by surgical excision. Search terms were: FEA, flat epithelial atypia, DIN1A, columnar cell, breast diseases, core needle biopsy. Inclusion criteria were: 1) manuscript with original data on FEA diagnosed on core needle biopsy, 2) data included outcome of cancer at surgical excision, 3) English Language.
RESULTS: Of 224 articles, 30 met inclusion criteria.
StudyTotal Pure FEA cases%N excisedN upgraded to cancer% upgradedLim, 2006862.55120Kunju 20071485.712325Martel 20076338.124938Piubello, 20093360.62000Chivukula, 20093989.735514Senneta,20094187.83600Hayes, 200981008113Davashian, 20091210012217Tamasino, 20095444.424313Noske, 20104369.83027Lee, 20101546.77114Ingegnoli, 20101883.315320Noel, 20106232.32000Flegg, 2010NANA5240Sohn, 20113666.72428Lavoue, 20116010060813Rakha, 20112410024521Soloranzo,20113384.828414Verschuur-Maes, 20116934.824938Peres, 201212879.71021010Uzoaru, 201214565.69533Bianchi, 2012190100190189Biggar, 2012511005136Yamaguchi, 20121747.18113Polom, 20122010020210Khoumais, 201310490.4941011Villa, 201314285.212176Becker, 201330378.9239104Ceugnart, 20136382.55236Uzan, 2013351003500
Across 1420 patients with pure FEA in 30 studies, observed proportions with upgrade to cancer varied from 0-40% with a pooled estimate of 11% (95% CI: 8-15%) using a random effects model. Test for heterogeneity was statistically significant (p &lt; 0.0001, I2 statistic=58%). After excluding 7 studies with &lt;50% (or unreported %) of all FEA cases excised, heterogeneity decreased (p=0.07, I2=32%) and the pooled estimate of cancer upgrade was 9% (95% CI: 7-12%). For upgrade to ADH, 693 subjects with pure FEA were analyzed from 21 studies. The percent upgraded to ADH ranged from 0-60% with significant heterogeneity (p &lt; 0.0001, I2 = 64%). Excluding 4 studies with &lt;50% of FEA cases excised did not improve heterogeneity (p &lt; 0.0001 and I2 = 66%). The random effects model pooled estimate of upgrade to ADH was 16% (95% CI: 11-23%) for the 21 studies and 17% (95% CI: 12-25%) for the subset of 17 studies.
CONCLUSION: The pooled upgrade rate of FEA to cancer was 9-11% and upgrade to ADH was 16-17%. For patients with FEA on core needle biopsy, surgical excision should be strongly considered.
Citation Format: Anatoliy V Rudin, Hoskin L Tanya, Ann M Farrell, Amy C Degnim. Flat epithelial atypia on core biopsy and upgrade to cancer: A systematic review and meta-analysis [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-13-06.