Do Birth Control Pills Increase the Risk of Breast Cancer?

Birth Control pills are made of synthetic versions of the hormones estrogenA female sex hormone that is primarily produced by the ovaries. Its primary function is to regulate the menstrual cycle and assist in the production of secondary sex characteristics such as breasts. It may even play a role in the production of cancer cells in the breast tissue. and progesteroneA hormone that stimulates the uterus to prepare for pregnancy, produced mainly by the ovaries. Progesterone may play a role in certain breast cancers.. These pills are widely used for preventing pregnancy and managing various health conditions. However, their relationship with breast cancer risk due to this hormonal exposure has been a topic of research and discussion.

The Introduction of Birth Control Pills

The invention and availability of the birth control pill allowed women, for the first time in history, to effectively exercise control over their reproductive health. The initial product, approved by the Food and Drug Administration (FDA) in 1957, was intended to treat severe or painful menstrual periods. In 1960, the FDA approved the pill for birth control. Since that time, women utilizing birth control pill have been able to

• manage their fertility
• experience less painful or heavy menstrual flow
• have lower risk of developing anemiaA lowered red-blood-cell count, which is often the result of chemotherapy. Symptoms include fatigue, shortness of breath, weakness, loss of energy, and skin pallor. (not having enough healthy red blood cells)
• manipulate the timing of their cycles to fit their social schedules.

Studies on long-term use have confirmed decreased risk in ovarian, endometrial, and colorectal cancers, and with women using the pill for 5 years or longer experiencing a slight reduction in total risk of cancer (1, 2).

Birth Control & Breast Cancer: What do the Studies Say?

However, in the mid 2010’s, concerns were raised when long-term studies suggested that birth control pill use was associated with an increased risk of breast cancer. The risk appeared to rise for every year of use (2,3). The results of these studies led American College of Obstetricians and Gynecologists (ACOG) to issue a practice advisory clarifying the magnitude of the risk as follows:

“The increased relative risk observed in the current study translates into one additional case of invasive breast cancer for every 7,690 women using hormonal contraception (1). This risk varied with age: for women younger than 35 years, there was one additional case of invasive breast cancer for every 50,000 women using hormonal contraception (1).”

This statement helped to bring perspective about the minimal impact on diagnostic rates, particularly for young women. Further, the advisory pointed out limitations of the studies, summarized the benefits of oral contraceptivesA hormonal pill, taken by mouth, used to prevent pregnancy., and urged physicians to review this information with patients during their counseling about available birth control methods and participating in shared decision-making.

Concerns about the interpretation of the results of various studies were also raised in a brief but comprehensive review by Franceschini et al (4). These authors pointed out that women in these trials utilized older preparations, which contained significantly higher doses of hormones than current products, that preparation varied between studies which were none-the-less grouped together, and that the design of the studies lacked the traditional scientific rigor. They pointed out that the increased risk of breast cancer ascribed to birth control pill use was equivalent to modifiable lifestyle risk such as low level of physical activity, obesity, and consumption of two glasses of wine per day. As in the physician advisory by ACOG, the authors balanced the reported increased risk of breast cancer with known benefits of oral contraceptive use.

The overwhelming evidence supports the use of birth control pills for its indications, and that health benefits for most women outweigh the small increased risk of breast cancer. Since the 1960s, women have become the dominant gender in the workforce. Control of reproduction has contributed greatly to enhancing economic freedom for women, resulted in limited size of families and improved the health and lifespan of women. Screening for breast cancer is effective, and if detected, is often highly curable. To provide perspective, according to American Cancer Society’s Facts and Figures, five-year survival rates are 91.2% and 10-year 86%. Risk of dying from breast cancer is one in forty-three women, or 2.3% in lifetime.

Balancing Benefits & Risks: What Should You Do?

When deciding on which form of birth control to consider, one must review potential risk factorsAnything that increases or decreases a person’s chance of developing a disease., such as personal and family history of cancers, known geneticInherited characteristics. mutation which significantly increases risk of breast and other cancers, modifiable lifestyle factors, and personal preferences. These should be balanced with known benefits of each form of birth control to make a choice that is best for them through shared decision-making with a trusted health professional.