title: Breast cancer survival among young women: a review of the role of modifiable lifestyle factors.
abstract: Almost 7% of breast cancers are diagnosed among women age 40 years and younger in Western populations. Clinical outcomes among young women are worse. Early age-of-onset increases the risk of contralateral breast cancer, local and distant recurrence, and subsequent mortality. Breast cancers in young women (BCYW) are more likely to present with triple-negative (TNBC), TP53-positive, and HER-2 over-expressing tumors than among older women. However, despite these known differences in breast cancer outcomes and tumor subtypes, there is limited understanding of the basic biology, epidemiology, and optimal therapeutic strategies for BCYW. Several modifiable lifestyle factors associated with reduced risk of developing breast cancer have also been implicated in improved prognosis among breast cancer survivors of all ages. Given the treatment-related toxicities and the extended window for late effects, long-term lifestyle modifications potentially offer significant benefits to BCYW. In this review, we propose a model identifying three main areas of lifestyle factors (energy imbalance, inflammation, and dietary nutrient adequacy) that may influence survival in BCYW. In addition, we provide a summary of mechanisms of action and a synthesis of previous research on each of these topics.
authors.affiliation: Department of Cancer Epidemiology and Prevention Research, CancerControl Alberta, Alberta Health Services, Room 513, Holy Cross Centre, Box ACB, 2210-2nd St. SW, Calgary, AB, T2S 3C3, Canada. Darren.Brenner@albertahealthservices.ca.|Department of Oncology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada. Darren.Brenner@albertahealthservices.ca.|Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada. Darren.Brenner@albertahealthservices.ca.
authors.forename: Darren R
authors.initials: DR
authors.lastname: Brenner
authors.affiliation: Department of Cancer Epidemiology and Prevention Research, CancerControl Alberta, Alberta Health Services, Room 513, Holy Cross Centre, Box ACB, 2210-2nd St. SW, Calgary, AB, T2S 3C3, Canada.|Department of Oncology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
authors.forename: Nigel T
authors.initials: NT
authors.lastname: Brockton
authors.affiliation: Women's College Research Institute, Women's College Hospital, Toronto, ON, Canada.|Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.|Department of Nutritional Sciences, University of Toronto, Toronto, ON, Canada.
authors.forename: Joanne
authors.initials: J
authors.lastname: Kotsopoulos
authors.affiliation: Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.|Prevention and Cancer Control, Cancer Care Ontario, Toronto, ON, Canada.
authors.forename: Michelle
authors.initials: M
authors.lastname: Cotterchio
authors.affiliation: Department of Nutritional Sciences, University of Toronto, Toronto, ON, Canada.|Prevention and Cancer Control, Cancer Care Ontario, Toronto, ON, Canada.
authors.forename: Beatrice A
authors.initials: BA
authors.lastname: Boucher
authors.affiliation: Faculty of Physical Education and Recreation, University of Alberta, Edmonton, AB, Canada.
authors.forename: Kerry S
authors.initials: KS
authors.lastname: Courneya
authors.affiliation: Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.|Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada.
authors.forename: Julia A
authors.initials: JA
authors.lastname: Knight
authors.affiliation: Department of Oncology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
authors.forename: Ivo A
authors.initials: IA
authors.lastname: Olivotto
authors.affiliation: Department of Oncology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.|Department of Surgery, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
authors.forename: May Lynn
authors.initials: ML
authors.lastname: Quan
authors.affiliation: Department of Cancer Epidemiology and Prevention Research, CancerControl Alberta, Alberta Health Services, Room 513, Holy Cross Centre, Box ACB, 2210-2nd St. SW, Calgary, AB, T2S 3C3, Canada.|Department of Oncology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.|Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Friedenreich
mesh_terms: D001943:Breast Neoplasms / Q000473:pathology*; D004032:Diet; D005260:Female; D006801:Humans; D008019:Life Style; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases; D017741:Survivors
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human
keywords: Breast cancer; Epidemiology; Lifestyle; Modifiable factors; Survival; Young onset