What is the relationship between oral contraceptives (hormonal birth control) and cancer risk?

From the Guidelines

Oral contraceptives significantly reduce the risk of ovarian cancer by approximately 50% in carriers of a pathogenic BRCA1 or BRCA2 variant, with longer duration of use providing greater protection. The evidence from a meta-analysis conducted in a large number of carriers of a pathogenic BRCA1/2 variant with and without ovarian cancer supports this finding, showing a summary relative risk of 0.51 for BRCA1 variant carriers and 0.52 for BRCA2 variant carriers 1.

Key Points to Consider

• The risk reduction for ovarian cancer associated with oral contraceptive use is substantial, with a 45%–50% reduction in risk for carriers of a pathogenic BRCA1 variant and a 60% reduction in risk for carriers of a pathogenic BRCA2 variant 1.
• The effect of oral contraceptives on breast cancer risk in carriers of a pathogenic BRCA1/2 variant is less clear, with conflicting data from case-control studies 1.
• A recent study found that oral contraceptive use is not significantly associated with breast cancer risk in carriers of a pathogenic BRCA1/2 variant, but the evidence is not yet conclusive 1.
• The decision to use oral contraceptives should balance the potential benefits, including reduced risk of ovarian cancer, with the potential risks, including a possible increased risk of breast cancer, and individual risk factors such as family history and genetic predispositions.

Clinical Implications

• Women with a known BRCA1/2 pathogenic or likely pathogenic variant should discuss their individual risk factors and the potential benefits and risks of oral contraceptive use with their healthcare provider.
• The use of oral contraceptives should be considered as part of a comprehensive risk reduction strategy for ovarian cancer in carriers of a pathogenic BRCA1 or BRCA2 variant.
• Further research is needed to fully understand the effects of oral contraceptives on breast cancer risk in carriers of a pathogenic BRCA1/2 variant, but current evidence suggests that the benefits of oral contraceptive use may outweigh the risks for many women 1.

From the FDA Drug Label

Epidemiology studies have not found a consistent association between use of combined oral contraceptives (COCs) and breast cancer risk. Studies do not show an association between ever (current or past) use of COCs and risk of breast cancer However, some studies report a small increase in the risk of breast cancer among current or recent users (<6 months since last use) and current users with longer duration of COC use Some studies suggest that oral contraceptive use has been associated with an increase in the risk of cervical intra-epithelial neoplasia in some populations of women (48). Benign hepatic adenomas are associated with oral contraceptive use, although the incidence of benign tumors is rare in the United States. Studies from Britain have shown an increased risk of developing hepatocellular carcinoma (43 to 45) in long-term (>8 years) oral contraceptive users

The use of oral contraceptives may be associated with an increased risk of certain types of cancer, including:

• Breast cancer: Some studies suggest a small increase in risk among current or recent users, particularly with longer duration of use.
• Cervical cancer: Oral contraceptive use may be associated with an increased risk of cervical intra-epithelial neoplasia.
• Hepatic neoplasia: Benign hepatic adenomas are associated with oral contraceptive use, and long-term use may increase the risk of hepatocellular carcinoma. However, the overall risk of cancer associated with oral contraceptive use is still unclear, and more research is needed to fully understand the relationship between oral contraceptives and cancer risk 2, 2, 2.

From the Research

Oral Contraceptives and Cancer Risk

• The use of oral contraceptives has been associated with a reduced risk of certain types of cancer, including endometrial and ovarian cancer 3, 4, 5, 6, 7.
• A study published in 2021 found that oral contraceptive use was associated with a lower risk of ovarian and endometrial cancer, with the protective effect increasing with longer duration of use 3.
• Another study published in 2004 found that oral contraceptives were associated with a reduction in the risk of endometrial and ovarian cancer, but a possible small increase in the risk of breast and cervical cancer 4.
• A systematic review and meta-analysis published in 2013 found that oral contraceptive use was associated with a significant reduction in the risk of colorectal and endometrial cancer, but a small increase in the risk of breast cancer 5.
• A study published in 2010 found that oral contraceptives probably promote the growth of existing breast cancer, but do not initiate it, and that the absolute number of additional breast cancer cases will be very small due to the low baseline incidence of the disease in young women 6.
• A systematic review and meta-analysis published in 2025 found that the use of oral contraceptives was inversely associated with the odds of having endometrial cancer, with the long-term use of oral contraceptives leading to the greatest odds reduction 7.

Specific Cancer Types

• Breast Cancer: The evidence suggests that oral contraceptive use may be associated with a small increase in the risk of breast cancer, particularly in current and recent users 3, 4, 5, 6.
• Ovarian Cancer: The use of oral contraceptives has been consistently associated with a reduced risk of ovarian cancer, with the protective effect increasing with longer duration of use 3, 4, 6.
• Endometrial Cancer: The evidence suggests that oral contraceptive use is associated with a significant reduction in the risk of endometrial cancer, with the long-term use of oral contraceptives leading to the greatest odds reduction 3, 4, 5, 6, 7.
• Cervical Cancer: The evidence suggests that oral contraceptive use may be associated with an increased risk of cervical cancer, particularly in current and recent users, but the risk is low and can be effectively prevented by periodic cervical screening 4, 6.
• Colorectal Cancer: The evidence suggests that oral contraceptive use is associated with a significant reduction in the risk of colorectal cancer 5.