Lobular neoplasia on core biopsy and risk factors to predict upstaging at surgical excision.

Abstract

Abstract Abstract #5009 Introduction: Lobular neoplasia (including atypical lobular hyperplasia and lobular carcinoma in-situ) identified on core biopsy (CB) is often recommended for surgical excision because the risk of upstaging to invasive carcinoma is documented to be 0-50%. We sought to identify risk factors to predict upstaging at surgical excisional biopsy.
 Methods: Retrospective chart review was used to identify women with CB revealing lobular neoplasia (LN) as highest risk pathological diagnosis. LN was defined as atypical lobular hyperplasia (ALH) and/or lobular carcinoma in situ (LCIS). Radiologic findings were correlated with pathology and excision results were recorded when available. Follow-up radiologic data was also recorded when available.
 Results: From 1997-2008, 45 women (age ranging from 33 to 81) underwent CB revealing LN. Ten had LCIS only, 34 had ALH only and 1 had both. Twenty five (56%) underwent surgical excision and 20 (44%) were followed clinically and mammographically. Core biopsy was recommended for mammographic microcalcifications (three with associated mass or focal asymmetry) in 29 pts (64%), while 14 CB (31%) were recommended for either mammographic mass or focal asymmetry only. Two CB (4%) were recommended for MRI abnormalities. For patients who underwent surgical excision, 8 (32%) were upstaged to invasive carcinoma or DCIS. Two of these 8 (25%) had LCIS on core biopsy and 6 (75%) had ALH only. Of the 6 pts with ALH only, the original core biopsy was done for focal asymmetry or mass in 3, abnormal MRI in 1 and microcalcifications in the remaining 2 (one with synchronous contralateral carcinoma). Patients not upstaged at surgical excision had original CB done for LCIS only in 5 (31%) and ALH only in 11 (69%). Of these 11 pts with ALH who were not upstaged, 8 underwent original CB for mass, focal asymmetry or MRI finding. Patients with LN on core biopsy done exclusively for mammographic microcalcifications underwent excision only 46% (13/28) of the time. Of those excised 4 were upstaged at surgical excision ( 3 with DCIS and 1 tubular carcinoma). Follow-up mammographic data was available for 65% (13/20) of patients who did not have surgical excision. At median follow-up of 16 months no new biopsies have been recommended and no new lesions have been identified for these patients.
 Conclusion :Of all patients who underwent surgical excision for LN found on core biopsy, 32% had a final diagnosis of either DCIS or invasive cancer. Of the 25 patients who underwent surgical excision, 24 were associated with one of the following risk factors: mass or focal asymmetry on mammogram, LCIS, synchronous contralateral carcinoma and non-concordant core biopsy. We did not identify any significant risk factors to predict upstaging at surgical excision, however, this may be due to selection bias. Further studies with larger number of patients are needed to identify risk factors to predict upstaging at surgical excision. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5009.