A Nation-Wide Multicenter Retrospective Study of the Epidemiological, Pathological and Clinical Characteristics of Breast Cancer In Situ in Chinese Women in 1999-2008

Background: Compared with invasive breast cancer, breast cancer in situ (BCIS) is seldom life threatening. However, an increasing incidence has been observed in recent years over the world. The purpose of our study is to investigate the epidemiological, clinical and pathological profiles of BCIS in Chinese women from 1999-2008. Methods: Four thousand and two hundred-eleven female breast cancer (BC) patients were enrolled in this hospital-based nation-wide and multi-center retrospective study. Patients were randomly selected from seven hospitals in seven representative geographical regions of China between 1999 and 2008. The epidemiological, clinical and pathological data were collected based on the designed case report form (CRF). Results: There were one hundred and forty-three BCIS cases in four thousand and two hundred-eleven BC patients (3.4%). The mean age at diagnosis was 48.3 years and BCIS peaked in age group 40-49 yrs (39.9%). The most common subtype was ductal carcinoma in situ (DCIS) (88.0%). 53.8% were positive for estrogen receptor (ER). Human epidermal growth factor receptor 2 (HER2) positive status was observed in 23.8% of patients. All patients underwent surgeries and 14.7% of them had breast conservation therapies (BCT) (21/143), but 41.9% accepted chemotherapy (64/143). Much less patients underwent radiotherapy (16.0%, 23/143) and among patients who had BCT, 67% accepted radiotherapy (14/21). Endocrine therapy was taken in 44.1% patients (63/143). Conclusions: The younger age of BCIS among Chinese women than Western countries and increasing number of cases pose a great challenge. BCT and endocrine therapy are under great needs.