Does Evra Increase Breast Cancer Risk?
Yes, Evra (norelgestromin/ethinyl estradiol transdermal patch) increases breast cancer risk by approximately 20-32%, similar to other combined hormonal contraceptives containing both estrogen and progestin.
Magnitude of Risk with Evra and Combined Hormonal Contraceptives
The evidence consistently demonstrates that combined hormonal contraceptives, including the transdermal patch, carry a small but measurable increased breast cancer risk:
Current or recent users of combined hormonal contraceptives have a relative risk of 1.20-1.26 for breast cancer compared to never-users 1, 2, 3.
The contraceptive patch specifically shows a relative risk of 1.32 (95% CI 1.17-1.49) for current or recent users 4.
Risk increases with duration of use: from 1.09 with less than 1 year of use to 1.38 with more than 10 years of use 3.
The absolute excess risk remains small: approximately 13 additional breast cancers per 100,000 person-years, or 1 extra case for every 7,690 women using hormonal contraception for 1 year 3.
The Progestin Component Drives the Risk
The critical factor is that progestin is responsible for the increased breast cancer risk, not estrogen alone:
Estrogen-only therapy does not increase breast cancer risk and may even reduce it (HR 0.77-0.80) 5, 2.
Adding progestin to estrogen creates the increased risk (HR 1.24-1.26) 1, 2.
Evra contains norelgestromin (a progestin) plus ethinyl estradiol, placing it in the higher-risk category of combined hormonal contraceptives 5, 6.
Age-Specific Absolute Risk Considerations
The absolute excess risk varies dramatically by age due to baseline breast cancer incidence:
Ages 16-20 years: 8 additional cases per 100,000 users over 15 years with 5 years of use 4.
Ages 35-39 years: 265 additional cases per 100,000 users over 15 years with 5 years of use 4.
Women under 34 have the highest relative risk increase, but their baseline breast cancer incidence remains very low, making the absolute risk minimal 7.
Risk Resolution After Discontinuation
The elevated risk disappears within 10 years after stopping hormonal contraception 7, 3.
Women who used hormonal contraceptives for 5+ years may have persistent elevation for several years after stopping, but this eventually resolves 3.
Contraindications Based on Breast Cancer History
Current breast cancer is an absolute contraindication (Category 4) to Evra or any combined hormonal contraceptive 7.
Past breast cancer with no evidence of disease for 5 years is Category 3 (risks usually outweigh benefits) 7.
Balancing Risks Against Benefits
When counseling patients about Evra, consider the protective effects against other cancers:
Combined hormonal contraceptives reduce colorectal cancer risk by 20-37% 5.
Ovarian cancer risk is reduced by approximately 50% with oral contraceptive use 7.
Endometrial cancer risk is significantly reduced 7.
Special Populations: Family History and BRCA Carriers
Women with family history of breast cancer do not appear to have significantly amplified risk with hormonal contraceptive use 7.
For BRCA1/2 carriers, evidence is conflicting: some studies show modest increased risk while others show no association or even decreased risk 7.
BRCA carriers benefit from 45-60% reduction in ovarian cancer risk with hormonal contraceptive use, which may outweigh breast cancer concerns 7.
Clinical Decision Algorithm for Evra
Step 1: Exclude absolute contraindications
- Current breast cancer diagnosis 7
- Breast cancer within the past 5 years 7
- Age ≥35 years with smoking (cardiovascular risk supersedes breast cancer concerns) 5, 7
Step 2: Assess patient age and baseline risk
- Women under 30: Absolute breast cancer risk increase is minimal despite elevated relative risk 7, 4
- Women 35-49: Absolute risk increase becomes more clinically significant (265 per 100,000 over 15 years with 5 years use) 4
Step 3: Consider alternative contraceptive methods
- Copper IUD (Category 1, no hormones, no breast cancer risk) 7
- Progestin-only methods carry similar breast cancer risk (RR 1.21-1.29) and offer no advantage over combined methods for breast cancer risk 4, 8
Step 4: Counsel on duration-dependent risk
- Limit duration to <5 years when possible to minimize cumulative risk 3
- Reassess need for continued use annually, especially in women approaching age 40 7
Common Pitfalls to Avoid
Do not overestimate absolute risk in young women: A 20-30% relative risk increase in a 25-year-old translates to minimal absolute risk given baseline incidence 7, 4.
Do not assume Evra has different breast cancer risk than oral combined contraceptives: The patch shows similar or slightly higher risk (RR 1.32) compared to oral combined pills (RR 1.23) 4.
Do not unnecessarily restrict Evra in women with family history alone: Evidence does not support significantly amplified risk without BRCA mutations 7.
Do not forget that progestin-only methods offer no breast cancer advantage: Progestin-only pills, injections, implants, and IUDs all show similar 20-30% increased risk 4, 8.
Do not ignore the cardiovascular risks that may be more immediately dangerous: In women ≥35 with smoking or other cardiovascular risk factors, VTE and stroke risks are more pressing concerns than breast cancer 5, 7.