title: Digital volumetric measurement of mammographic density and the risk of overlooking cancer in Japanese women.
abstract: BACKGROUND
  Breast density often affects cancer detection via mammography (MMG). Because of this, additional tests are recommended for women with dense breasts. This study aimed to reveal trends in breast density among Japanese women and determine whether differences in breast density differentially affected the detection of abnormalities via MMG.
  
  
  METHODS
  We retrospectively analyzed 397 control women who underwent MMG screening as well as 269 patients who underwent surgery for breast cancer for whom preoperative MMG data were available. VolparaDensity™ (Volpara), a three-dimensional image analysis software with high reproducibility, was used to calculate breast density. Breasts were categorized according to the volumetric density grade (VDG), a measure of the percentage of dense tissue. The associations between age, VDG, and MMG density categories were analyzed.
  
  
  RESULTS
  In the control group, 78% of women had dense breasts, while in the breast cancer group, 87% of patients had dense breasts. One of 36 patients with non-dense breasts (2.7%) was classified as category 1 or 2 (C-1 or C-2), indicating that abnormal findings could not be detected by MMG. The proportion of patients with breast cancer who had dense breasts and were classified as C-1 or C-2 was as high as 22.3%.
  
  
  CONCLUSIONS
  The proportions of Japanese women with dense breasts were high. In addition, the false-negative rate for women with dense breasts was also high. Owing to this, Japanese women with dense breasts may need to commonly undergo additional tests to ensure detection of breast cancer in the screening MMG.
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan. terusan@med.showa-u.ac.jp.
authors.forename: Terumasa
authors.identifier: http://orcid.org/0000-0002-8975-9325
authors.initials: T
authors.lastname: Sawada
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Sadako
authors.initials: S
authors.lastname: Akashi
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Seigo
authors.initials: S
authors.lastname: Nakamura
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kuwayama
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Enokido
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Miwa
authors.initials: M
authors.lastname: Yoshida
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Rikako
authors.initials: R
authors.lastname: Hashimoto
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Toshimi
authors.initials: T
authors.lastname: Ide
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Masuda
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Kanae
authors.initials: K
authors.lastname: Taruno
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Oyama
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Takamaru
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Kanada
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Murasaki
authors.initials: M
authors.lastname: Ikeda
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Natsuko
authors.initials: N
authors.lastname: Kosugi
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Sato
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Sayuka
authors.initials: S
authors.lastname: Nakayama
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Arisa
authors.initials: A
authors.lastname: Ata
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Tonouchi
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Haruna
authors.initials: H
authors.lastname: Sakai
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Matsunaga
authors.affiliation: Department of Breast Surgical Oncology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Matsutani
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001940:Breast / Q000000981:diagnostic imaging / Q000473:pathology; D000071060:Breast Density; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D055088:Early Detection of Cancer / Q000009:adverse effects / Q000379:methods*; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000009:adverse effects* / Q000379:methods; D007564:Japan; D008327:Mammography / Q000009:adverse effects*; D008403:Mass Screening / Q000009:adverse effects / Q000379:methods*; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies
keywords: Dense breast; Volpara density grade