A study of clinical outcome and biomarker profiles of Japanese breast cancer patients according to mammographic density

Introduction: Mammographic density (MD) has been reported to be associated with increased risk of breast cancer development. In addition, the association of MD with breast cancer subtypes has been proposed in Caucasian breast cancer patients but this has remained virtually unknown in Asian patients. Therefore, in this study, we retrospectively examined the subtypes and clinical prognosis in Japanese cancer patients according to their MD. Method: We retrospectively examined 781 mammograms of breast cancer patients from March 2013 to March 2016 at Nahanishi Clinic, Okinawa, Japan. In this study, MD was tentatively classified according to the recommendation of the Japanese Central Organization on Quality Assurance of Breast Cancer Screening, based on the proportion of fat area as follows; (a) extremely high dense:10-20%, (b) heterogeneously dense:40-50%, (c) scattered fatty:70-90%, (d) fatty: almost all the breast fat. “Dense breast” includes extremely high and heterogeneous dense. We also evaluated the rates of recurrence and breast cancer specific death according to MD defined as above. The status of breast cancer subtypes was also compared between dense and non-dense breasts, and between pre-menopausal and post-menopausal women. Result: Among 781 cases examined, 365 were classified as dense breasts and 416 as non-dense breasts. The median age of all the patients examined was 57 years old. The age was significantly younger (50.4 vs 63.4 years old P Citation Format: Naoko Takigami, Kentaro Tamaki, Yoshihiko Kamada, Kano Uehara, Seiko Tsuchiya, Shigeharu Terukina, Takanori Ishida, Minoru Miyashita, Keely May McNamara, Hironobu Sasano, Nobumitsu Tamaki. A study of clinical outcome and biomarker profiles of Japanese breast cancer patients according to mammographic density [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-01-01.