Table 2.

Summary of the high-risk women eligible for chemoprevention and the risks and benefits of selective estrogen receptor modulators (SERMs) and aromatase inhibitors (AIs) for primary prevention

Patient population for chemoprevention	Benefits of chemoprevention	Risks of chemoprevention
Eligible women:	Selective estrogen receptor modulators:	Selective estrogen receptor modulators:
• Age ≥ 60 years	• 30–50% relative risk reduction in breast cancer incidence	• Vasomotor symptoms, vaginal symptoms, leg cramps
• Five-year risk of invasive breast cancer ≥ 1.67% according to the Gail model	• 33% relative risk reduction in fractures	• Increased risk of cataracts (tamoxifen)
• Ten-year risk of breast cancer ≥ 5% according to the Tyrer-Cuzick model	• Only effective against estrogen receptor-positive breast cancer	• Increased risk of uterine cancer (tamoxifen)
	• Not associated with an overall survival benefit	• Increased risk of thromboembolism
High-risk women with a favorable risk/benefit profile from chemoprevention:	Aromatase inhibitors:	Aromatase inhibitors:
• Age < 50 years	• 50–65% relative risk reduction in breast cancer incidence	• Vasomotor symptoms, vaginal dryness, arthralgias
• Prior hysterectomy	• Only effective against estrogen receptor-positive breast cancer	• Increased risk of osteoporosis
• Atypical hyperplasia or lobular carcinoma in situ	• Not associated with an overall survival benefit	• Increased risk of hyperlipidemia and hypertension
• BRCA2 mutation carriers