Abstract P6-01-01: Risk of Invasive Breast Cancer and Ductal Carcinoma In-Situ in Women with Atypical Papillary Lesions of the Breast

Abstract

Abstract Background: Benign papillary lesions of the breast including papilloma and papillomatosis are believed to be associated with a low risk of developing breast cancer. The risk of breast cancer development in patients who have an atypical papilloma or who have a papilloma in conjunction with atypical hyperplasia is not well defined. Methods: All patients who underwent a biopsy at Duke University Medical Center between October 1992 and December 2009 for a papillary lesion of the breast were identified. Patients were excluded if they had a previous or concurrent diagnosis of invasive or in-situ malignancy or less than 6 months of follow up. The remaining patients were analyzed to determine the risk of developing breast cancer. Results: Median follow up for the 167 patients with a papillary lesion of the breast included in the analysis was 4.6 years. 51 patients had an atypical papillary lesion. 111 patients had atypical hyperplasia in conjunction with a papilloma. 35 patients had a papilloma without atypia or atypical hyperplasia. Patients with an atypical papilloma were more likely to develop an invasive or in-situ breast cancer with a 5 year actuarial risk of 13.0% (24 patients at risk) versus 4.6% (49 patients at risk) (p=0.03). Patients who had atypical hyperplasia in conjunction with a papilloma were also more likely to develop invasive or in-situ breast cancer with a 5 year actuarial risk of 9.8% (48 patients at risk) versus 0% (15 patients at risk) (p=0.05). In the group with an atypical papillary lesion, the actuarial risk of ipsilateral breast cancer or DCIS development was 8.2% at 5 years (24 patients at risk) and 21.1% at 10 years (12 patients at risk). In the group with atypical hyperplasia in conjunction with a papilloma, the actuarial risk of ipsilateral breast cancer development was 3.9% at 5 years (48 patients at risk) and 8.5% at 10 years (18 patients at risk). The majority of patients underwent an excisional biopsy for their papilloma (150 patients). Patients who had a core needle biopsy alone had a 5 year actuarial risk of ipsilateral breast cancer or DCIS of 15.3% versus 2.0% for patients who had an excisional biopsy (p=0.03). All of the patients who had only a core biopsy and later developed an ipsilateral cancer or in-situ disease had an atypical papilloma. Discussion: Papillary lesions of the breast with atypical features may be associated with an increased risk of breast cancer and DCIS. Atypical papillary lesions should be fully excised or followed closely. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-01-01.