[5044] The increasing diagnosis of breast cancer risk markers: atypia and lobular carcinoma in situ. Lenahan C, Rufo T, Lamb CC, Edwards MA, Pories SE. Mount Auburn Hospital, Cambridge, MA; Beth Israel Deaconess Medical Center, Boston, MA Introduction: The availability of medical interventions to reduce a woman's risk of breast cancer has led to increasing interest in breast cancer risk assessment. Atypical lobular hyperplasia (ALH) and atypical ductal hyperplasia (ADH), and lobular carcinoma in situ (LCIS) are considered markers for an increased risk of breast cancer. While Surveillance, Epidemiology, and End Results (SEER) data tracks the incidence of LCIS, there is limited information available about the prevalence of atypia. In this study, we document the diagnoses of ALH, ADH and LCIS in biopsies of radiologic abnormalities over a nine-year period at the Mount Auburn Hospital in Cambridge, Massachusetts. Methods and Materials: Records of biopsies done for radiologic abnormalities from 1997 through 2005 were examined from the Hoffman Breast Center at Mount Auburn Hospital, a Harvard Medical School community teaching hospital in Cambridge, MA. Institutional Review Board approval for the study was obtained. Linear regression analysis was performed to evaluate statistical significance. Results: The number of mammograms performed at the Mount Auburn Hospital during this time period doubled from 4,240 in 1997 to 7886 in 2005. While the total number of biopsies increased, the percent of biopsies done for abnormal mammograms did not change significantly (p= 0.44). The diagnosis of LCIS has increased from 3 (0.6%) of biopsies in 1997 to 24 (4%) in 2005 (P=0.0013). The diagnoses of ADH and ALH increased from 21 (5%) in 1997 to 49 (8%) in 2005 (P=.0.065). 39 % (39/100) of the LCIS cases and 42% (143/344 cases) of the atypia diagnoses were read by 2 or more pathologists in the department. In addition, 6 (6%) cases of LCIS and 29 (8%) of atypia cases were sent to outside institutions for confirmation. There was no significant change in benign biopsies, ductal carcinoma in situ or invasive cancer during this time period. Conclusions: This study shows a statistically significant increase in the diagnoses of LCIS over a nine-year period. A steady increase in the diagnosis of atypia was also demonstrated although this was not statistically significant. While the change in the frequency of these diagnoses may be due to an increase in mammographic screening, the current focus on the identification of LCIS and atypia as a guide for medical intervention and risk reduction may contribute to increased pathologic recognition. Changes in pathology staff reading breast biopsies or in patient demographics at Mount Auburn Hospital over this time period may be contributing factors as well. Additional studies with larger numbers of patients are needed to validate the increased diagnosis of breast cancer risk markers and these results highlight the need to track rates of these diagnoses carefully over time. San Antonio Breast Cancer Symposium, 12/06 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.