PAPILLARY APOCRINE CHANGE OF THE BREAST - ASSOCIATIONS WITH ATYPICAL HYPERPLASIA AND RISK OF BREAST-CANCER

(1)Micropapillary patterns of apocrine change in human female breasts are common histological findings. They have been identified as cancer associated and implicated as an indicator of cancer risk in a predicti ve manner. This study has stratified papillary apocrine change (PAC) i nto categories of increasing complexity using a combination of cytolog ical and histological pattern rules. Cases (2,876) were identified in a review of 10,357 benign breast biopsies, Of 5966 women, 1613 had PAC and were followed for a median of 20 years after biopsy for the devel opment of invasive carcinoma of the breast. There was a slight associa tion with cancer risk elevation, but most of this disappeared when wom en with concurrent, specifically identified patterns of atypical hyper plasia (AH) were excluded from the groups with PAC. The resultant rela tive risk was only 1.2 after women with AH were excluded. Only 1% of t he reviewed biopsies demonstrated highly complex patterns of PAC, and 20% of these had coexistent lesions of AH. Women with highly complex p atterns of PAC without AH did experience a relative risk of 2.4 (95% c onfidence-interval. = 0.77-7.04) but without statistical significance. More than one-half of all PAC: patterns occurred without concurrent f oci of lesions of proliferative disease that are associated with a sli ght elevation of breast cancer risk (at least 1.5 times); when present without proliferative disease, there was no suggestion of later breas t cancer risk for PAC.