ARID1A is a useful marker of malignancy in peritoneal washings for endometrial carcinoma. Issue 4 (29th December 2014)

• Record Type: Journal Article
• Authors: Nagymanyoki, Zoltan; Mutter, George L.; Hornick, Jason L.; Cibas, Edmund S.
• Is Part Of: Cancer cytopathology. Volume 123:Issue 4(2015:Apr.)
• Page Start: 253
• Page End: 257
• Publication Date: 2014-12-29
• Subjects: Cancer -- Cytopathology -- Periodicals; Pathology, Cellular -- Periodicals; Cytology -- Technique -- Periodicals; 611.01815
• DOI: 10.1002/cncy.21514
• Languages: English
• ISSNs: 1934-662X

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="cncy21514-sec-0001" sec-type="section"> <title>BACKGROUND</title> <p> <italic>ARID1A</italic> (AT‐rich interactive domain 1A gene) has recently been identified as a novel tumor suppressor gene and one of the driver genes in endometrial carcinogenesis. Approximately 30% to 40% of endometrial carcinomas harbor mutations in the <italic>ARID1A</italic> gene, which results in complete loss of <italic>ARID1A</italic> protein expression. Although <italic>ARID1A</italic> aberrations are not restricted to endometrial cancer, the authors hypothesized that it might be a useful marker of malignancy in peritoneal washings for patients with endometrial cancer.</p> </sec> <sec id="cncy21514-sec-0002" sec-type="section"> <title>METHODS</title> <p>The cytology archive of Brigham and Women's Hospital was searched to identify cell blocks from peritoneal washings that contained malignant or benign endometrial epithelium. From 2006 through 2013, 17 cases of endometrial carcinoma (EMCA) and 16 cases of endometriosis were identified. Surgical pathology reports and follow‐up data were used to confirm the diagnoses. Immunohistochemistry for <italic>ARID1A</italic> was performed, and slides were scored as 0 (complete loss of staining) or 1 (retained staining) by 2 independent pathologists. The discordant cases were resolved by consensus. The two‐tailed Fisher exact probability test was used to calculate statistical significance.</p> </sec> <sec id="cncy21514-sec-0003" sec-type="section"> <title>RESULTS</title> <p>Complete loss of <italic>ARID1A</italic> expression was found in 8 of 17 EMCA cases (47%) and none of the 16 endometriosis cases (0%) (<italic>P</italic> = .024). The concordance among the pathologists on first review was high (96.7%).</p> </sec> <sec id="cncy21514-sec-0004" sec-type="section"> <title>CONCLUSIONS</title> <p>The results of the current study demonstrated that <italic>ARID1A</italic> can be used in peritoneal washings to confirm malignancy in patients with EMCA. Complete loss of <italic>ARID1A</italic> expression by immunohistochemistry is highly specific for carcinoma, but retained expression is not informative. <bold><italic>Cancer (Cancer Cytopathol)</italic> 2015;123:253–257.</bold> © <italic>2014 American Cancer Society.</italic></p> </sec> </abstract>