In this article, we will discuss the evidence on how to prevent primary breast cancer.
Have you ever heard of the term "primary"?
There are many ways to refer to primary and secondary breast cancer, but primary means that the disease has no other origin.
In the case of cancer, whether it is primary or secondary is determined based on the classification of the disease, even if it has metastasized from other parts of the body or is benign or malignant.
This is an important factor in the treatment of cancer, so please note that the results of the study presented here were effective for "primary" cancers.
What the study says
The conclusion of this study is that cancer prevention drugs (CPA) can reduce the risk of developing breast cancer.
Study.
Six studies conducted in 2018 included 50,927 women who were randomized to receive one CPA (SERM: tamoxifen or raloxifene; AI: exemestane or anastrozole) and a placebo.
Three studies compared tamoxifen with placebo.
Two studies compared AI (exemestane or anastrozole) with placebo.
One study compared tamoxifen with raloxifene.
One study compared tamoxifen and raloxifene.
In the tamoxifen vs. placebo comparison, the risk of developing breast cancer was lower in the tamoxifen group than in the placebo group.
As for adverse events of concern, there seems to be a possibility of a higher risk of severe toxicity in comparison.
In particular, there was a higher incidence of both endometriosis and thromboembolism in women who were randomized to tamoxifen.
In a comparison of AI and placebo, there was a 53% reduction in the risk of breast cancer with AI (exemestane or anastrozole).
In terms of adverse events of concern, the AI was found to increase the risk of severe toxicity by 18%.
Endocrine (e.g. hot flashes), gastrointestinal (e.g. diarrhea), and musculoskeletal (e.g. arthralgia) adverse events were reported, but there was no difference in endometriosis and thromboembolism rates.
In a comparison between tamoxifen and raloxifene, raloxifene was worse than tamoxifen in terms of reducing breast cancer incidence.
By indirectly comparing treatment efficacy, SERMs and AIs were compared in this review.
In terms of efficacy, it appears that AI (exemestane or anastrozole) may have slightly reduced breast cancer incidence compared to tamoxifen.
However, the certainty of the evidence obtained was low and the toxicity data could not be analyzed due to lack of convergence of the models.
Mocellin S, Goodwin A, Pasquali S. Risk-reducing drugs for primary breast cancer: a network meta-analysis. Cochrane Database of Systematic Reviews 2019, No. 4. Number: CD012191. doi: 10.1002 / 14651858.CD012191.pub2.
Summary.
Although the risk of developing breast cancer is reduced, the possibility of drug damage cannot be ignored, so it seems that the mutual risks and benefits need to be weighed in determining the treatment.
What would I do if I were you? I wondered what I would do, but as someone who has experienced the side effects of drugs, I thought I would consider a different approach.
It will be a difficult part of the process, but I hope you will think about it when you are consulted or when it happens to you.
