*For medical professionals only
Ladies and gentlemen, are you emotionally stable today? If not, for the sake of our mammary glands and thyroid gland, let's put aside our worries for a while and relax our mood for a while
We always say that breast cancer is ventilated. This is because negative emotions such as depression, anxiety, and anger can affect the endocrine system, resulting in abnormal estrogen levels in women. In the long term, it may have a profound impact on the endocrine system and its target organs, induce the occurrence of thyroid nodules and breast nodules, and may even increase the risk of thyroid cancer or breast cancer.
This is not to be underestimated. According to the latest statistics, breast cancer alone accounts for 31% of female cancers in the United States [1]. In China, breast cancer is the leading cause of cancer death among women aged 15 to 44 years, and the mortality rate is still on the rise [2].
Of course, emotions are a difficult thing to understand, and when the power of hormones and the stress of reality can't be avoided, is there any other way to protect the mammary glands?
That's sports!
Kimberly D. Mille and colleagues at the London Cancer Institute, UK, based on data from a large cohort of 550,000 premenopausal women, have yielded the strongest evidence to date that physical activity during leisure time prevents breast cancer, associated with a 43% lower risk of HER2-positive breast cancer. The article was recently published in the journal Journal of Clinical Oncology.
Screenshot of the first page of the paper
Previously, studies have provided evidence that physical activity in leisure time is inversely associated with a woman's risk of breast cancer after menopause. However, when it comes to the risk of premenopausal breast cancer, the results of existing studies are inconsistent due to the small number of cohorts and incomplete statistical methods.
The study included a total of 547601 premenopausal women from North America, Europe, Asia, and Australia, with a median age of 41.3 years. At a median follow-up of 11.5 years, a total of 10,231 people were diagnosed with breast cancer in situ or aggressive.
Physical activity in leisure time is defined as exercise, exercise, walking, etc., which are performed spontaneously by individuals, rather than basic activities in daily life. The researchers used metabolic equivalence (MET) to quantify participants' physical activity levels and quintile groupings to calculate hazard ratios (HR) using the Cox proportional hazards model.
After adjusting for variables such as age, timing of menarche, parity, smoking, and oral contraceptive use, the analysis showed that the highest level of physical activity (above the 90th percentile) was associated with a 6% reduction in breast cancer risk (HR, 0.94; 95% CI, 0.89-0.99) compared with the lowest level of physical activity (below the 10th percentile).
When the effect of body mass index is excluded, the benefits of exercise are even more pronounced, with the highest levels of physical activity being associated with a 10% lower risk of breast cancer compared with the lowest levels (HR, 0.90; 95% CI, 0.85-0.95).
Correlation between physical activity level and breast cancer risk (A and B before and after adjusting BMI)
After further evaluation of the different subtypes of breast cancer, the researchers found that the negative correlation between exercise and cancer risk was particularly strong, especially for a specific pathological type, HER2-positive breast cancer. The highest level was associated with a 43% reduction in the risk of HER2-positive breast cancer compared with the lowest level of physical activity (HR, 0.57; 95% CI, 0.39-0.84). There was no significant correlation between triple-negative breast cancer and physical activity levels.
Correlation between each breast cancer subtype and physical activity level (left and right, before and after adjusting BMI)
This large pooled analysis provides further evidence that engaging in higher levels of leisure time physical activity may reduce the risk of premenopausal breast cancer.
Therefore, in order to protect our mammary glands, in addition to maintaining a beautiful mental state or occasionally going crazy steadily, we should also take a lot of stroll and exercise appropriately when we have free time to rest~
Bibliography:
[1] Siegel, R. L., Miller, K. D., Wagle, N. S., & Jemal, A. (2023). Cancer statistics, 2023. CA: a cancer journal for clinicians, 73(1), 17–48. https://doi.org/10.3322/caac.21763
[2] Hong R, Xu B. Breast cancer: an up-to-date review and future perspectives. Cancer Commun (Lond). 2022 Oct; 42(10):913-936. doi: 10.1002/cac2.12358.
[3]https://ascopubs.org/doi/10.1200/JCO.23.01101
The author of this article丨Zhang Aidi