Breast cancer: The Pill and breast cancer risk

Since the early 1960s, oral contraceptives have become the most popular and one of the most effective forms of contraception used in the UK. But an association between oestrogen and an increased risk of breast cancer has led to a continuing debate about the role contraceptive pills may play in developing breast cancer.

For most women, especially young women, experts say the benefits of oral contraceptives far outweigh the risks. Here are some frequently asked questions and answers about the controversy.

Does taking birth control pills increase my risk of developing breast cancer?

Maybe. Studies that have examined the use of oral contraceptives as a risk factor for breast cancer have produced conflicting results. Some researchers think this might be due to the fact that the level of hormones in birth control pills has changed since they were first studied. Early contraceptive pills contained much higher levels of hormones than today's low-dose pills.

Scandinavian researchers have noted an increase in breast cancer in a group of women who were currently taking or had recently taken contraceptive pills. Longer use of the Pill seemed to increase the risk. Similar research found that 10 years or more after women stopped using contraceptive pills, their breast cancer risk returned to the same level as if they had never used them.

However, another reputable 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 oral contraceptives.

In general, most studies have not found an overall increased risk of breast cancer due to the use of oral contraceptives.

My family has a history of breast cancer. Should I take oral contraceptives?

Maybe. A study published in the Journal of the American Medical Association found that women with a strong family history of breast cancer may have up to an 11 times higher risk of breast cancer if they have ever taken "the Pill". However, experts caution that the study involved mainly women who took contraceptive pills prior to 1975, when it contained much higher levels of the hormones oestrogen and progestin than today's lower-dose pill.

Those with a family history of breast cancer related to mutations in the BRCA genes should use caution before taking oral contraceptives. Families at increased risk of breast cancer who are carriers of alterations in these genes may further increase their risk of breast cancer by taking contraceptive pills. Recent studies show taking contraceptive pills did not increase the risk in women who are carriers of the abnormal form of the BRCA2 gene, but did in those with the altered BRCA1 gene.

Women should discuss their family history of cancer with their GP or family planning clinic doctor when evaluating the risks and benefits of using contraceptive pills.