P4-10-08: Risk Factor Profiles of Women with DCIS and Invasive Ductal Breast Cancers.

Abstract

Background There are well established risk factors for breast cancer, including elements of personal and family history. Ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) have long been viewed as representing two points on the spectrum of one disease. There is limited and conflicting information in the literature regarding risk factor profiles for DCIS as compared with IDC. The purpose of this study was to investigate the relationship of established risk factors in a population of women newly diagnosed with pure DCIS and IDC. Methods The Breast Cancer Database at NYU Langone Medical Center was queried for women who were diagnosed with pure DCIS and IDC from 1/2010-3/2011. Variables of interest included: age, family history of breast cancer (FHBC), BRCA1/2 status, age at menarche and menopause, parity, age at first birth, breast feeding, body mass index (BMI), history of atypical hyperplasia or lobular carcinoma in situ (ADH, ALH, LCIS), stage, ER/PR status, and method of presentation. Wilcoxon non-parametric tests, Chi-Square tests, and Fisher's Exact Tests were used to evaluate differences among DCIS and IDC patients. Results Of the 593 women identified in this study, 140 (24%) had pure DCIS and 453 (76%) had IDC. The median age at diagnosis was 59 years. There were 9 (1.5%) BRCA1/2 mutation carriers. Of these, 7 had IDC and 2 had DCIS. The majority of patients with IDC were stage I (67%) and ER/PR+ (73%). The majority of patients with DCIS were also ER/PR+ (71%). In our cohort, the majority of DCIS (83%) was mammographically detected versus 47% of IDC cases. There were no statistically significant differences in breast cancer risk factors between the two groups. Conclusions In contrast to some previously published work, the risk factor profile in our cohort was similar for patients with IDC and DCIS. In this population, the majority of cases of DCIS were detected mammographically, underscoring the importance of mammography in early detection of breast cancer. There is increasing interest in identifying a population of women with DCIS who might never progress to invasive disease. Our data suggests that this population is unlikely to be distinguished by its risk factor profile. Genetic and molecular characteristics are more likely to provide the criteria by which this subgroup of patients is identified. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-10-08.