[104] Histology of Breast Cancer in Patients with Lynch Syndrome

Barina Aqil, Banu Arun, Nour Sneige, Angelica M Gutierrez-Barrera, Daniel Rosen, Susan Abrahams, Erika Resetkova, Yun Wu, Constance T Albarracin. Baylor College of Medicine, Houston, TX; MD Anderson Cancer Center, Houston, TX

Background: Germline mutations for Lynch syndrome (LS) are associated with colon, small intestine, stomach, endometrium, upper urinary tract and sebaceous tumors of the skin. While breast cancer is not considered to be a LS-associated tumor, more recent studies have described early onset of breast tumors in patients with LS. Our goal is to evaluate the histopathological features of breast cancers associated with LS.
Design: Women with primary breast cancer who had biopsy or /and surgery at our institution were included in this study. A search recovered 24 cases of LS-associated breast cancers from 1987-2012. We were able to retrieve the slides for 13 patients.
Results: The mean age of diagnosis of invasive breast cancer in Lynch syndrome cases was 51.5 years. The most common accompanying tumors included colon cancer in 39% (13 of 33) and endometroid carcinoma grade I in 15% (5 of 33). Breast tumor types included invasive ductal carcinoma (21 of 25), invasive lobular carcinoma (1 of 25) and metaplastic carcinoma (1 of 25). Only 2 cases of DCIS were identified not associated with invasive tumor. Infiltrating ductal carcinomas had low grade in 12% (3 of 23), intermediate grade in 26% (6 of 23) and high grade in 30% (7 of 23). The biologic markers were tested in 15 invasive ductal, 1 invasive lobular and 1 metaplastic breast tumors that showed, 18% (3 of 17) were ER-/HER2+, 18% (3 of 17) were ER+/HER2 +, 53% (9 of 17) were ER+ /HER2 – and 12% (2 of 17) were ER-/HER2- . DCIS was low grade in 6.6% (1 of 15), intermediate grade in 53% (8 of 15)and high grade in 40% (6 of 15). 27% of DCIS in Lynch patients also showed periductal fibrosis. Out the 2 DCIS cases not associated with invasive tumor only 1 case was tested for biologic markers and was ER+/HER2-. Immunohistochemical stains and mutational analysis for DNA mismatch repair (MMR) gene products showed loss of MLH1 alone in 14% (3/21), PMS2 alone in 4.8% (1/21), MSH2 alone in 9.5% (2/21), MSH 6 alone in 4.8% (1/21), MLH1/PMS2 in 57% (12/21), MSH2/MSH6 in 9.5% (2/21). Lynch patients showed fibrocystic changes(46%) and with 17% of cases having intraductal papillomatosis
Conclusions: Invasive breast tumors and DCIS in Lynch syndrome tend to have an intermediate to high nuclear grade, be ER+/HER2-, and show loss of MLH1/PMS2 markers. Approximately half of the patients with Lynch syndrome showed fibrocystic changes with one third having intraductal papillomatosis.
Category: Breast

Monday, March 4, 2013 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 13, Monday Morning


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