B irth control pills have become one of the most popular and effective forms of birth control in the U.S. since they were introduced in the 1960s. But an association between estrogen in birth control pills and an increased risk of breast cancer has led to an ongoing debate about the role they may play. The results of recent studies are more inconsistent but seem to suggest a slight hike in breast cancer risk for current or recent users of progestin-only pills.
For most people, especially those younger than 45, experts say the benefits of birth control pills far outweigh the dangers. Talk to your doctor about which options might be best for you. There are nonhormonal choices -- including the copper IUD, contraceptive gel, and multiple barrier methods -- if you want to avoid hormones.
Here are answers to some of the most frequently asked questions.
Does taking birth control pills increase my risk of developing breast cancer?
Maybe. The results of studies on oral contraceptives as a risk factor for breast cancer are conflicting. Some researchers think this might be because the levels of hormones in birth control pills have changed since they were first studied. They had much higher amounts, particularly estrogen, than today's low-dose pills. So they may have carried more of a risk for breast cancer and other side effects.
Scandinavian researchers noted an increase in breast cancer in a group of women that were currently taking or had recently taken birth control pills. Longer use of the pill seemed to raise the risk. Similar research found that 10 years or more after women stopped using birth control pills, their breastcancer risk returned to the same level as if they had never used birth control them.
However, another study by Women's Contraceptive and Reproductive Experience (Women's CARE) done between 1994 and 1998 showed there was no increased risk of breast cancer in current or former users of birth control pills.
In general, most studies have not found a significant overall increased risk of breast cancer because of oral contraceptives. With that said, certain factors may affect your risk, including using birth control pills for longer than 5 years or before your first full-term pregnancy.
My family has a history of breast cancer. Should I take birth control pills?
Consider alternative forms of contraception. A study published in the Journal of the American Medical Association found that the risk of breast cancer may be up to 11 times higher in women with a strong family history of breast or ovarian cancer (meaning at least five blood relatives had been diagnosed) if they have ever taken the pill. But experts caution that the study mainly involved women who took birth control pills prior to 1975. They contained much higher levels of the hormones estrogen and progestin than today's lower-dose pill.
Talk through options with your doctor. They can help you decide what's best for you.
Does the risk of breast cancer associated with birth control pills depend on age?
Maybe, but the evidence is mixed. In general, the chances of breast cancer go up with age. And some studies have found that those aged 45 and over who were still using the pill have a slightly higher chance of getting breast cancer compared to those younger than 45.
The highest risk seems to be with people who currently use the pill and have been on it for longer than 5-10 years. While the overall risk for breast cancer from the pill is small, you should talk to your doctor about the pros and cons of all your birth control choices if you’re in your 40s and 50s.
Do birth control pills lessen the risk of other cancers?
Yes. The pill's protective effect against ovarian cancer has been well documented. Ovarian cancer risk is lowered by as much as 30%-50% among people taking birth control pills for at least 3 years. New studies show that as little as 1 year of use can dramatically reduce the risk of ovarian cancer. That protective effect increases the longer a woman is on the pill.
Researchers have also seen lower endometrial cancer rates.
Several studies suggest oral contraceptives may also curb the risk of colorectal cancers. Some researchers have found that people who had used birth control pills were about 15%-20% less likely to get colorectal cancers than those who had never taken them. The risk was lowered even if someone had only started taking the pills recently.
