Plasma microRNA ratios associated with breast cancer detection in a nested case-control study from a mammography screening cohort

Mammographic breast cancer screening is effective in reducing breast cancer mortality. Nevertheless, several limitations are known. Therefore, developing an alternative or complementary non-invasive tool capable of increasing the accuracy of the screening process is highly desirable. The objective of this study was to identify circulating microRNA (miRs) ratios associated with BC in women attending mammography screening. A nested case-control study was conducted within the ANDROMEDA cohort (women of age 46-67 attending BC screening). Pre-diagnostic plasma samples, information on life-styles and common BC risk factors were collected. Small-RNA sequencing was carried out on plasma samples from 65 cases and 66 controls. miR ratios associated with BC were selected by two-sample Wilcoxon test and lasso logistic regression. Subsequent assessment by RT-qPCR of the miRs contained in the selected miR ratios was carried out as a platform validation. To identify the most promising biomarkers, penalised logistic regression was further applied to candidate miR ratios alone, or in combination with non-molecular factors. Small-RNA sequencing yielded 20 candidate miR ratios associated with BC, which were further assessed by RT-qPCR. In the resulting model, penalised logistic regression selected seven miR ratios (miR-199a-3p_let-7a-5p, miR-26b-5p_miR-142-5p, let-7b-5p_miR-19b-3p, miR-101-3p_miR-19b-3p, miR-93-5p_miR-19b-3p, let-7a-5p_miR-22-3p and miR-21-5p_miR-23a-3p), together with body mass index (BMI), menopausal status (MS), the interaction term BMI * MS, life-style score and breast density. The ROC AUC of the model was 0.79 with a sensitivity and specificity of 71.9% and 76.6%, respectively. We identified biomarkers potentially useful for BC screening measured through a widespread and low-cost technique. This is the first study reporting circulating miRs for BC detection in a screening setting. Validation in a wider sample is warranted.Trial registration: The Andromeda prospective cohort study protocol was retrospectively registered on 27-11-2015 (NCT02618538).

[Did social isolation during the SARS-CoV-2 epidemic have an impact on the lifestyles of citizens?]

OBJECTIVES

to study the impact of social isolation, related to the SARS-CoV-2 epidemic, on lifestyles in Italy, with particular reference to physical activity, alcohol consumption, smoking, and eating habits. Moreover, to investigate the association between lifestyle changes during the pandemic and sociodemographic characteristics.

DESIGN

epidemiological investigation based on a cross-sectional study.

SETTING AND PARTICIPANTS

between April 21st and June 7th 2020, an electronic questionnaire to collect information on physical activity, alcohol consumption, smoking, and eating habits during the period of home containment was made available on the web. Respondents were recruited through non-probabilistic snowball sampling. The link to the electronic questionnaire was disseminated through institutional websites, social networks (Facebook, Twitter), and messaging systems such as WhatsApp, Telegram, and SMS. A total of 10,758 interviews were collected, of which 7,847 (73%) were complete for a minimum set of indicators (age, gender, and area of residence).

MAIN OUTCOME MEASURES

reduction of physical activity, increase in alcohol consumption, increase in cigarette smoking, increase in consumption of unhealthy foods (processed meat, red meat or desserts) without increasing healthy foods (vegetables, legumes or whole grains) and, vice versa, increase in consumption of healthy foods without increasing unhealthy foods.

RESULTS

the population under study consists of 7,847 people with a mean age of 48.6 years (standard deviation: 13.9). Most of respondents are women (71.3%), 92.5% have a high school or university degree and 91% live in Northern Italy. During home containment, 56% of interviewees reported they had reduced the time devoted to physical activity. In particular, this happened among older people and those living in large cities. More than 17% of respondents increased their alcohol consumption, especially men, those highly educated and those living in large urban centres. Older age and residence in the Southern Italy represent, instead, protective factors for this outcome. Among smokers, 30% increased cigarette consumption during the period of home containment, on average of 5.6 cigarettes per day. A small proportion of former smokers (0.6%) resumed smoking. With regard to eating habits, 3 out of 10 respondents (29.9%) reported an inappropriate eating behaviour (increasing unhealthy food without increasing healthy ones). This behaviour was less frequent among men (adjusted Prevalence Ratio 0.80, p=0.005). A lower percentage of respondents (24.5%) increased the consumption of healthy foods without increasing the consumption of unhealthy ones.

CONCLUSIONS

the results of this survey show that social isolation during the SARS-CoV-2 pandemic has had an impact on citizens' behaviours. In particular, it was found a noteworthy increase in sedentariness, alcohol consumption, and tobacco smoking. A meaningful proportion of respondents reported a worsening of eating habits, especially among women. However, for each of the behavioural risk factors investigated, small proportions of respondents with resilient attitudes were also found, namely, capable of taking advantage of social isolation for improving their daily habits. Studying changes in lifestyles during a pandemic, identifying population groups most at risk of adopting unfavourable behaviours, is a useful tool for policy makers to plan targeted and effective public health interventions.