Yuko Minami1,2,3, Yoshikazu Nishino4,5, Masaaki Kawai6, Hiroshi Tada7, Seiki Kanemura4, Minoru Miyashita7, Takanori Ishida7, Yoichiro Kakugawa6. 1. Division of Community Health, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan. adym@med.tohoku.ac.jp. 2. Division of Cancer Epidemiology and Prevention, Miyagi Cancer Center Research Institute, 47-1 Nodayama, Medeshima-Shiode, Natori, Miyagi, 981-1293, Japan. adym@med.tohoku.ac.jp. 3. Center for Preventive Medicine, Osaki Citizen Hospital, 2-3-15 Senjuji-machi, Furukawa, Osaki, Miyagi, 989-6174, Japan. adym@med.tohoku.ac.jp. 4. Division of Cancer Epidemiology and Prevention, Miyagi Cancer Center Research Institute, 47-1 Nodayama, Medeshima-Shiode, Natori, Miyagi, 981-1293, Japan. 5. Department of Epidemiology and Public Health, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Kahoku, Ishikawa, 920-0293, Japan. 6. Department of Breast Surgery, Miyagi Cancer Center Hospital, 47-1 Nodayama, Medeshima-Shiode, Natori, Miyagi, 981-1239, Japan. 7. Department of Breast and Endocrine Surgical Oncology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.
Abstract
BACKGROUND: Reproductive factors may influence breast cancer progression and patient survival; however, evidence has been limited. METHODS: The associations of reproductive factors with tumor characteristics and patient survival were analyzed among 1468 breast cancer patients diagnosed during 1997-2013 at a single institute in Japan. The patients were followed until 2016. During a median follow-up period of 8.6 years, 272 all-cause and 199 breast cancer deaths were documented. RESULTS: In case-case comparisons, later age at menarche was inversely associated with advanced tumors. Nulliparous patients tended to have receptor-positive [estrogen receptor (ER)+ or progesterone receptor (PR)+] tumors. Conversely, the Cox proportional-hazards model including adjustment for tumor characteristics revealed U-shaped relationship between parity number and the risk of all-cause death among the patients overall [hazard ratio (HR) = 2.10 for nulliparous, 1.28 for 2, and 1.50 for ≥ 3 vs. one child]. According to hormone receptor, later age at menarche and later age at last birth were positively associated with the risk of all-cause death among patients with ER- and PR- cancer (menarche, HR = 2.18 for ≥ 15 vs. ≤ 12 years, ptrend = 0.03; last birth, HR = 3.10 for ≥ 35 vs. ≤ 29 years, ptrend = 0.01). A shorter time since last birth was associated with the risk of death among receptor-positive patients (HR = 5.72 for ≤ 4 vs. ≥ 10 years, ptrend = 0.004). CONCLUSION: The results indicate that the timing of menarche and parity have significant effects on patient survival, providing clues for understanding the association between women's life course and breast cancer outcome.
BACKGROUND: Reproductive factors may influence breast cancer progression and patient survival; however, evidence has been limited. METHODS: The associations of reproductive factors with tumor characteristics and patient survival were analyzed among 1468 breast cancerpatients diagnosed during 1997-2013 at a single institute in Japan. The patients were followed until 2016. During a median follow-up period of 8.6 years, 272 all-cause and 199 breast cancer deaths were documented. RESULTS: In case-case comparisons, later age at menarche was inversely associated with advanced tumors. Nulliparous patients tended to have receptor-positive [estrogen receptor (ER)+ or progesterone receptor (PR)+] tumors. Conversely, the Cox proportional-hazards model including adjustment for tumor characteristics revealed U-shaped relationship between parity number and the risk of all-cause death among the patients overall [hazard ratio (HR) = 2.10 for nulliparous, 1.28 for 2, and 1.50 for ≥ 3 vs. one child]. According to hormone receptor, later age at menarche and later age at last birth were positively associated with the risk of all-cause death among patients with ER- and PR- cancer (menarche, HR = 2.18 for ≥ 15 vs. ≤ 12 years, ptrend = 0.03; last birth, HR = 3.10 for ≥ 35 vs. ≤ 29 years, ptrend = 0.01). A shorter time since last birth was associated with the risk of death among receptor-positive patients (HR = 5.72 for ≤ 4 vs. ≥ 10 years, ptrend = 0.004). CONCLUSION: The results indicate that the timing of menarche and parity have significant effects on patient survival, providing clues for understanding the association between women's life course and breast cancer outcome.
Entities:
Keywords:
Age at menarche; Breast cancer; Hormone receptor; Parity; Reproductive factors; Survival