title: Prognosis of breast cancer is associated with one-carbon metabolism related nutrients among Korean women.
abstract: BACKGROUND
  The 5-year survival rate for breast cancer among Korean women has increased steadily; however, breast cancer remains the leading cause of cancer mortality among women. One-carbon metabolism, which requires an adequate supply of methyl group donors and B vitamins, may affect the prognosis of breast cancer. This aim of this study was to investigate the associations of dietary intake of vitamin B2, vitamin B6 and folate before diagnosis on the prognosis of breast cancer.
  
  
  METHODS
  We assessed the dietary intake using a food frequency questionnaire with 980 women who were newly diagnosed and histopathologically confirmed to have primary breast cancer from hospitals in Korea, and 141 disease progression events occurred. Cox's proportional hazard regression models were used to estimate the hazard ratio (HR) and 95% confidence interval (95% CI) adjusting for age, education, recruitment sites, TNM stage, hormone status, nuclear grade and total calorie.
  
  
  RESULTS
  There was no significant association between any one-carbon metabolism related nutrients (vitamin B2, B6 and folate) and the progression of breast cancer overall. However, one-carbon metabolism related nutrients were associated with disease progression in breast cancer patients stratified by subtypes. In ER + and/or PR + breast cancers, no association was observed; however, in ER-/PR- breast cancers, a high intake of vitamin B2 and folate statistically elevated the HR of breast cancer progression (HR = 2.28; 95% CI, 1.20-4.35, HR = 1.84; 95% CI, 1.02-3.32, respectively) compared to a low intake. This positive association between the ER/PR status and progression of the disease was profound when the nutrient intakes were categorized in a combined score (Pinteraction = 0.018). In ER-/PR- breast cancers, high combined scores were associated with a significantly poor DFS compared to those belonging to the low score group (HR = 3.84; 95% CI, 1.70-8.71).
  
  
  CONCLUSIONS
  In conclusion, our results suggest that one-carbon related nutrients have a role in the prognosis of breast cancer depending on the ER/PR status.
authors.affiliation: Department of Biomedical Sciences, Seoul National University, Seoul, Republic of Korea.
authors.forename: Yunhee
authors.initials: Y
authors.lastname: Lee
authors.forename: Sang-Ah
authors.initials: SA
authors.lastname: Lee
authors.forename: Ji-Yeob
authors.initials: JY
authors.lastname: Choi
authors.forename: Minkyo
authors.initials: M
authors.lastname: Song
authors.forename: Hyuna
authors.initials: H
authors.lastname: Sung
authors.forename: Sujee
authors.initials: S
authors.lastname: Jeon
authors.forename: Sue K
authors.initials: SK
authors.lastname: Park
authors.forename: Keun-Young
authors.initials: KY
authors.lastname: Yoo
authors.forename: Dong-Young
authors.initials: DY
authors.lastname: Noh
authors.forename: Sei-Hyun
authors.initials: SH
authors.lastname: Ahn
authors.forename: Daehee
authors.initials: D
authors.lastname: Kang
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000378:metabolism; D015331:Cohort Studies; D002149:Energy Intake; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage* / Q000009:adverse effects; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D011960:Receptors, Estrogen / Q000187:drug effects / Q000378:metabolism; D011980:Receptors, Progesterone / Q000187:drug effects / Q000378:metabolism; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D012256:Riboflavin / Q000008:administration & dosage* / Q000009:adverse effects; D012307:Risk Factors; D011795:Surveys and Questionnaires; D025101:Vitamin B 6 / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D025101:Vitamin B 6; D005492:Folic Acid; D012256:Riboflavin