Age at first childbirth and breast cancer survival: a prospective cohort study

Breast cancer: Epidemiology, risk factors and screening

Breast cancer is a global health concern with a significant impact on the well-being of women. Worldwide, the past several decades have witnessed changes in the incidence and mortality of breast cancer. Additionally, epidemiological data reveal distinct geographic and demographic disparities globally. A range of modifiable and non-modifiable risk factors are established as being associated with an increased risk of developing breast cancer. This review discusses genetic, hormonal, behavioral, environmental, and breast-related risk factors. Screening plays a critical role in the effective management of breast cancer. Various screening modalities, including mammography, ultrasound, magnetic resonance imaging (MRI), and physical examination, have different applications, and a combination of these modalities is applied in practice. Current screening recommendations are based on factors including age and risk, with a significant emphasis on minimizing potential harms to achieve an optimal benefits-to-harms ratio. This review provides a comprehensive insight into the epidemiology, risk factors, and screening of breast cancer. Understanding these elements is crucial for improving breast cancer management and reducing its burden on affected individuals and healthcare systems.

Breast cancer in young women: a rising threat: A 5-year follow-up comparative study

Introduction

Breast cancer in young women is usually considered as breast cancer occurring in women younger than 40 years and is the most frequent cancer-related cause of death in these patients. In the past few years, there seems to be an increasing trend in the prevalence of breast cancer in young women, which, associated with poorer prognosis, more aggressive histologic features, and more frequent recurrence rates, makes it a rising threat to young women. This study aimed to evaluate the biological behavior of breast cancer in young women in our institution.

Material and methods

A retrospective, unicentric, cohort study was conducted between 2012 and 2016. All consecutive patients with breast cancer were enrolled in the study. Cases were divided into two groups: case group, those younger than 40 years, and control group, those 40 years or older. The exclusion criterion was nonoperative treatment. Several clinical and pathologic parameters were evaluated, as well as were overall survival time and disease-free survival time.

Results

The incidence of breast cancer in young women presented a rising tendency over the study period. Significant differences were observed in the comparison of the groups according to body mass index, age at menarche, age at birth of the first child, and proliferation rate. There were no differences in overall survival and disease-free survival rates between the groups.

Conclusions

Young women had a more symptomatic presentation, a greater tumor proliferation rate, but similar outcomes compared with older patients. Greater multicentric studies are needed to confirm or refute these results.

Associations of reproductive breast cancer risk factors with breast tissue composition

BACKGROUND

We investigated the associations of reproductive factors with the percentage of epithelium, stroma, and fat tissue in benign breast biopsy samples.

METHODS

This study included 983 cancer-free women with biopsy-confirmed benign breast disease (BBD) within the Nurses' Health Study and Nurses' Health Study II cohorts. The percentage of each tissue type (epithelium, stroma, and fat) was measured on whole-section images with a deep-learning technique. All tissue measures were log-transformed in all the analyses to improve normality. The data on reproductive variables and other breast cancer risk factors were obtained from biennial questionnaires. Generalized linear regression was used to examine the associations of reproductive factors with the percentage of tissue types, while adjusting for known breast cancer risk factors.

RESULTS

As compared to parous women, nulliparous women had a smaller percentage of epithelium (β = - 0.26, 95% confidence interval [CI] - 0.41, - 0.11) and fat (β = - 0.34, 95% CI - 0.54, - 0.13) and a greater percentage of stroma (β = 0.04, 95% CI 0.01, 0.08). Among parous women, the number of children was inversely associated with the percentage of stroma (β per child = - 0.01, 95% CI - 0.02, - 0.00). The duration of breastfeeding of ≥ 24 months was associated with a reduced proportion of fat (β = - 0.30, 95% CI - 0.54, - 0.06; p-trend = 0.04). In a separate analysis restricted to premenopausal women, older age at first birth was associated with a greater proportion of epithelium and a smaller proportion of stroma.

CONCLUSIONS

Our findings suggest that being nulliparous as well as having a fewer number of children (both positively associated with breast cancer risk) is associated with a smaller proportion of epithelium and a greater proportion of stroma, potentially suggesting the importance of epithelial-stromal interactions. Future studies are warranted to confirm our findings and to elucidate the underlying biological mechanisms.