Study links birth-control pills with cervical cancer

Oral contraceptives, also called birth-control pills, are widely consumed by millions of women to help prevent pregnancy, but these pills may put those women at a significant risk of developing cervical cancer and other cancers of the womb, says a recent study conducted by international researchers.

The long-term use of birth control pills doubles the women’s risk of developing cervical cancer, the novel Oxford-based research has confirmed. The women, who have been using these pills for at least five years are at nearly twice the risk of cervical cancer, compared with women who have never used the pill, the study concludes.

The news is yet another blow to oral contraceptives. Earlier this month, a European study linked the pills to an increased risk of heart disease, even for women who no longer use the pills, giving shock to those women who are taking these pills for the last many years.

The latest study, which was published in the medical journal The Lancet, found that taking birth control pills for five years doubles the chance that a woman will get cancer of the cervix, the lower, neck- like part of the womb, compared with those who never used the pills.

But, the Cancer Research UK study, which took place in Oxford, also shows that the risk starts falling soon after the use of pill is stopped. However, it takes nearly 10 years for the risks to return to the level for women who have never used the pill.

"This study confirms that women who are taking the pill have a small increased risk of cervical cancer. But this increased risk begins to drop soon after women stop taking the pill and after 10 years risk has returned to normal levels,” the researchers reported.

To confirm their findings of a link between birth-control pills and the incidence of cervical cancer, Dr Jane Green, lead researcher based at Cancer Research UK's epidemiology unit at the University of Oxford and colleagues analyzed data from 24 studies involving as many as 52,082 women, of whom 16,573 were with cervical cancer and 35,509 without it.

After analyzing the data from these birth control pill studies that covered women from 26 countries worldwide, the researchers noticed that in developed countries the overall rate of cervical cancer among women up to the age of 50 who have never used oral contraceptives is 3.8 cases per 1,000 women. The risk of developing cervical cancer rises slightly to 4 in 1,000 for women who took the pill for at least five years, and 4.5 in 1,000 for those who use it for a decade.

In developing countries, the use of oral contraceptives boosted the risk of cervical cancer from 7.3 to 8.3 per 1000 women.

The oral contraceptives, which contain estrogen and progestagen, though increase the cervical cancer risk, and even are thought to raise the chance of breast cancer, but at the same time they can protect against tumors in the ovaries and the endometrial lining of the womb.

According to the Atlanta-based American Cancer Society’s estimates, nearly 3,670 women will die from the cervical form of the disease in the U.S. this year, while more than 22,000 will die from ovarian and endometrial tumors.

"The pill remains one of the most effective forms of contraception, and in the long-term the small increases in risk for cervical and breast cancers are outweighed by reduced risks for ovarian and womb cancer," concludes the study, which was funded by the World Health Organization, the International Agency for Research on Cancer and Cancer Research UK.

Introduced in the 1960s, the oral contraceptives are medicines are taken by mouth to help prevent pregnancy. Commonly known as birth control pill, the medicine is now the world's most popular form of contraception used by more than 12 million women in the United States and more than 60 million women worldwide, as per the estimates of U.S. Centers for Disease Control and Prevention.

The contraceptive pill that revolutionized birth control practices uses hormones to suppress ovulation. The pill, typically containing estrogen or progesterone, inhibits ovulation and thereby prevents conception.