Annual report of the Japanese Breast Cancer Registry for 2017

Naoki Hayashi, Hiraku Kumamaru, Urara Isozumi, Kenjiro Aogi, Sota Asaga, Kotaro Iijima, Takayuki Kadoya, Yasuyuki Kojima, Makoto Kubo, Minoru Miyashita, Hiroaki Miyata, Masayuki Nagahashi, Naoki Niikura, Etsuyo Ogo, Kenji Tamura, Kenta Tanakura, Yutaka Yamamoto, Masayuki Yoshida, Shigeru Imoto, Hiromitsu Jinno

Research output: Contribution to journalArticlepeer-review

21 Citations (Scopus)


Background: The Japanese Breast Cancer Society Registry started in 1975; it was transferred to the registry platform of the National Clinical Database in 2012. We provide the annual data and an analysis of the Breast Cancer Registry for 2017. Methods: Patients’ characteristics and pathological data of the 95,203 registered Japanese breast cancer patients from 1,427 institutes in 2017 were obtained. Trends in age at diagnosis and pathological stage were determined during the most recent 6 years (2012–2017). Results: The mean onset age was 60.2 years with bimodal peaks at 45–49 years and 65–69 years. A short-term trend of the most recent 6 years of data caused the second, older peak. At diagnosis, 32.4% of breast cancer patients were premenopausal. The distribution of stages revealed that the proportion of early stage breast cancer (stage 0–I) increased up to 60%. At the initial diagnosis, 2.2% of patients presented with metastatic disease. Sentinel node biopsy without axillary node dissection was performed without neoadjuvant chemotherapy (NAC) in 68.8%, and with NAC in 31.1%, of patients. For patients without NAC, lymph node metastasis was less than 3% if the tumor size was less than 1 cm. The proportion of node-negativity decreased to 79.5% when tumor size was 2.1–5 cm. Conclusions: This analysis of the registry provides new information for effective treatment in clinical practice, cancer prevention, and the conduct of clinical trials. Further development of the registry and progress in collecting prognostic data will greatly enhance its scientific value.

Original languageEnglish
Pages (from-to)803-809
Number of pages7
JournalBreast Cancer
Issue number5
Publication statusPublished - 2020 Sept 1
Externally publishedYes


  • Annual report
  • Breast cancer
  • Breast cancer
  • Japanese Breast Cancer Society
  • National clinical database
  • Neoadjuvant chemotherapy
  • Registry

ASJC Scopus subject areas

  • Oncology
  • Radiology Nuclear Medicine and imaging
  • Pharmacology (medical)


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