A Review of Modifiable Risk Factors in Young Women for the Prevention of Breast Cancer

Abstract

Breast cancer is the most common cancer diagnosis in women aged less than 40 years and the second most common cause of cancer death in this age group. Global rates of young onset breast cancer have risen steadily over the last twenty years. Although young women with breast cancer have a higher frequency of underlying pathogenic mutations in high penetrance breast cancer susceptibility genes (CSG) than older women, the vast majority of young breast cancer patients are not found to have a germline CSG mutation. There is therefore a need to inform young women regarding non-genetic breast cancer risk factors which have the potential to be influenced by changes in individual behaviour. A Pubmed search was performed using the search terms “young” or “early onset”, and “breast cancer” and “modifiable risk”. Titles and abstracts from peer-reviewed publications were screened for relevance. This review presents evidence for potentially modifiable risk factors of breast cancer risk in young women, including lifestyle factors (physical activity, body habitus, alcohol use, smoking, shift work and socioeconomic factors), reproductive and hormonal factors and iatrogenic risks. The extent to which these factors are truly modifiable is discussed and interactions between genetic and non-genetic risk factors are also addressed. Health care professionals have an opportunity to inform young women about breast health and risk when presenting at a “teachable moment”, including the benefits of physical activity and alcohol habits as risk factor. More focussed discussions regarding individual personal risk and benefit should accompany conversations regarding reproductive health and take into consideration both non-modifiable and iatrogenic BC risk factors.

Women's health and night shift work: Potential targets for future strategies in breast cancer (Review)

“…Sleep deprivation, resulting in shift work disorder, characterised by excessive sleepiness and sleep disturbances ( 79 ), has a strong influence on the neuro-immune-endocrine axis, which can affect cell proliferation and immune responses, including cytokine production ( 80 ) and some plasma metabolites, that may play an essential role in the circadian system ( 81 ). In particular, Daly et al ( 8 ) described a 16% increase in the incidence of BC in women aged 25-49 since 1990s, which may be at least partly attributed to more improved screening programs and detection methods, as well as changing lifestyles, highlighting the role of the endocrine factors in the onset of BC. In fact, younger women (<40 years) seem to be affected by more aggressive phenotypes of BC, resulting in a higher mortality rate.…”

“…Moreover, young women were more likely to exhibit advanced disease stage tumours (larger size, lymph node involvement, poorly differentiated). Still, women aged <40 years seem to have a higher frequency of familiar history of BC, with a higher frequency of pathogenic mutations in the BC genes (BRCA1, BRCA2, TP53 and PALB2) compared with women with BC that develops after the age of 40, thus mutation penetrance appears higher in younger patients ( 8 ).…”

“…However, there are also less common inherited mutations in other genes, including ATM, TP53, CHEK2, PTEN, CDH1, STK11 and PALB2( 7 ). Lifestyle is an important risk factor, with lack of physical activity, excessive consumption of alcohol, a high body mass index (BMI), a high-fat diet and smoking all increasing the risk ( 2 , 8-11 ). Ethnicity, age and socio-economic status can influence the risk of developing BC.…”

Circulating Omentin-1 as a Biomarker at the Intersection of Postmenopausal Breast Cancer Occurrence and Cardiometabolic Risk: An Observational Cross-Sectional Study

“…Besides the well-established risk factors including age, genetic susceptibility, reproductive and hormonal factors, lifestyle and environmental determinants (sedentary life, alcohol consumption, diet, etc. ), obesity, and metabolic syndrome (Mets) have also been associated with an increased risk of BC, particularly, postmenopausal BC (PBC) [ 5 , 6 , 7 , 8 , 9 , 10 ].…”

“…The strengths of the study include its novelty; the considerable number of clinical and laboratory data; the blind determination of parameters by the laboratory staff; the use of a highly specific ELISA kit for omentin-1 determination; and the enrolment of four groups (newly diagnosed treatment-naïve patients, healthy control participants, cases with BBL, and obese postmenopausal women) of similar age. The limitations of our study include: (1) its cross-sectional nature which cannot demonstrate causality, but could unravel hypotheses to be examined in future large, prospective, and multicentric studies; (2) its modest sample size of cases and controls to enable reliable estimates of joint effects, to identify effect modifiers, and to conduct multivariate subgroup analyses; (3) its small sample size of postmenopausal women with BBL and obesity; (4) its dependence on a single blood sample from study participants, although there are no significant issues regarding reproducibility and reliability in omentin-1 determinations over a chronic time period [75]; (5) the potential of residual confounding by other undetermined variables, which always exist as a possibility in all studies; (6) the non-use of the standard methods of computed tomography (CT) or magnetic resonance imaging (MRI) to quantify abdominal adipose tissue in study participants. Due to ionizing radiation risks, it is not appropriate to determine abdominal fat with CT in many research and clinical studies.…”