# Pharmacological Prevention in Breast Cancer: Current Evidence, Challenges, and Future Directions

## TL;DR

This review discusses how medicines can prevent breast cancer in high-risk women, but their use is limited due to side effects and low awareness, and suggests new strategies to improve adoption.

## Contribution

The paper provides an updated overview of breast cancer pharmacoprevention and proposes novel approaches like low-dose therapies and digital tools to increase uptake.

## Key findings

- Tamoxifen, raloxifene, and aromatase inhibitors significantly reduce estrogen receptor-positive breast cancer in high-risk women.
- Adverse effects and lack of awareness are major barriers to the use of breast cancer preventive medicines.
- New strategies like low-dose tamoxifen, digital decision aids, and emerging drugs may improve acceptance and adherence.

## Abstract

Breast cancer remains the most common cancer in women worldwide, and new cases continue to rise in many countries. Medicines that block estrogen activity, such as tamoxifen, raloxifene, anastrozole, and exemestane, have been shown in large clinical trials to reduce the risk of developing breast cancer in women at increased risk. However, very few eligible women choose to take these preventive medicines. This review explains why prevention is important, what we currently know about the benefits and risks of available medicines, and why their use remains so limited in everyday practice. We also highlight new strategies being studied, such as using lower doses, alternative schedules, digital tools to support decision making, and the development of new medicines and vaccines. By summarizing evidence and emerging approaches, this review aims to support more informed choices and encourage wider adoption of breast cancer prevention.

Background/Objectives: Pharmacological prevention is an evidence-based strategy to reduce the incidence of hormone receptor-positive breast cancer in high-risk women. Despite strong data from randomized trials, clinical uptake remains low. This review aims to summarize the efficacy, safety, and clinical implementation of pharmacoprevention and explore novel approaches to improve uptake. Methods: A comprehensive literature review was conducted on pharmacologic agents used for breast cancer risk reduction, including selective estrogen receptor modulators (SERMs) and aromatase inhibitors (AIs). The review also examines risk assessment models, guideline recommendations, barriers to implementation, and emerging strategies such as low-dose therapies and digital decision aids. Results: Tamoxifen, raloxifene, and AIs significantly reduce the incidence of estrogen receptor-positive breast cancer in high-risk populations. However, adverse effects and poor awareness limit their use. Personalized risk models and newer approaches, including low-dose tamoxifen, digital health tools, and emerging agents such as SERDs and GLP-1 receptor agonists, may improve acceptability and adherence. Conclusions: Pharmacoprevention offers substantial benefits in appropriately selected women. Future efforts should focus on new drugs, precision risk stratification, individualized decision-making, and overcoming barriers to implementation to maximize the impact of preventive strategies in breast cancer control.