[267] Is Routine Testing for Hormone Receptors Necessary in the Clinical Management of Grade 1 Breast Carcinomas?

Wanlin A Shen, C James Sung, Cunxian Zhang, Margaret M Steinhoff, Michele Lomme, Rochelle A Simon, Shahrzad Ehdaivand, W Dwayne Lawrence, M Ruhul Quddus. Brown University/Women & Infants Hospital, Providence, RI; Chi Mei Hospital, Liouying, Tainan, Taiwan

Background: Assessment of hormone receptors (HR) status (estrogen receptor [ER] and progesterone receptor [PR]) of breast cancers (BRCAs) and HER2 status has been routine clinical practice and these prognostic/predictive biomarkers are considered integral to breast cancer management. It is generally believed that low grade tumors are typically HR positive and high grade tumors are more likely to be HR negative. However, the frequency of HR expression in low grade invasive BRCAs and ductal carcinomas in situ (DCIS) has not been reported. The correlation of nuclear grade (NG) and HR status in low grade BRCAs is also unknown. We investigated the frequency of HR expression in low grade BRCAs and whether such HR status correlates with NG, and advanced stage, with the aim to propose the possibility of elimination of routine HR testing in this group.
Design: All invasive and in situ BRCAs diagnosed between 2004-2008 were retrieved, and grade 1 tumors (including all histologic types) were evaluated for HR status. All invasive BRCAs were graded utilizing the Nottingham histologic score and low grade DCIS was defined as having NG 1.
Results: A total of 1505 cases of BRCAs were identified, of which 149 (9.9%) cases were grade 1 (136 invasive carcinomas and 13 DCIS), from patients ranging in age from 37 to 86 years (median 55 years). The invasive BRCAs included: 110 (80.9%) infiltrating ductal carcinomas, 9 (6.6%) mucinous carcinomas, 9 (6.6%) invasive tubular carcinomas, 6 (4.4%) infiltrating lobular carcinomas, 1 (0.7%) infiltrating cribriform carcinoma, and 1 (0.7%) invasive micropapillary carcinoma. The mean tumor size was 1.12 cm (range: 0.1-7.2 cm; median: 1.0 cm.). All 149 (100%) low grade invasive BRCAs and DCIS expressed ER regardless of lymph node status or presence of lymphovascular invasion (LVI). When invasive BRCAs were stratified by NG, all 48 grade 1 and all 87 grade 2 expressed ER. Of 136 invasive BRCAs, 125 (91.9%) expressed PR. PR was positive in 41 (85.4%) NG1 cases and in 83 (95.4%) NG2 cases. The one case of invasive BRCA with NG3 was positive for both ER and PR.
Conclusions: Our findings suggest that 100% of grade 1 invasive BRCAs express ER and 91.9% express PR regardless of NG, histologic type, lymph node status, or LVI. Therefore, routine evaluation of HR status (particularly ER) may not be necessary in the clinical management of grade 1 BRCAs. A multi-institutional study with a larger number of cases may be necessary to further validate these findings.
Category: Breast

Wednesday, March 21, 2012 9:30 AM

Poster Session V # 27, Wednesday Morning

 

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