Birth Control Pill Linked to Cervical CancerNov 9, 2007 | Parker Waichman LLP
Birth control pills increase the chance that a woman will develop cervical cancer and other cancers of the womb, according to new research. The 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 cervical cancer. The Lancet article represents the second bit of bad news about birth control pill side effects this week, as another group of researchers recently linked the Pill to an increase in arterial plaque.
The Lancet study was conducted by a group of international researchers who analyzed data from 24 birth control pill studies that covered more than 50,000 women. In industrialized countries the overall rate of cervical cancer among women who have never taken the pill is 3.8 cases per 1,000 women. The rate rises to 4.0 per 1,000 in women who took the pill for five years and 4.5 for those who took it for 10 years. For women who are well-screened for cervical cancer – meaning they get regular pap smears and have access to good medical care -- that translates into an additional two cases per 10,000 women. In less-developed countries where screening is not as prevalent, however, that translates to an increased risk of about 40 cases per 10,000.
The researchers are not sure why birth control pills increase a woman’s risk of developing cervical cancer. The disease's primary cause is the human papillomavirus, not the hormones found in birth control pills. The Pill may make cervical cells more susceptible to infection by the human papillomavirus, or the hormones contained in birth control pills could be accelerating the cancer's progression once an infection occurs.
The researchers did offer some good news to women who use birth control pills. The cervical cancer risk does appear to drop off once a patient stops using the Pill. When that occurred, the chance of developing the cancer reverted to the same level as non-pill users.
That is at least more comforting than what some other birth control pill researchers reported earlier this week. A Belgian study concluded that women who used the pill had an increase in the amount of plaque buildup in the blood vessels supplying the legs and brain. The study found that for every 10 years that a woman used birth control pills, the amount of plaque in these vessels increased by as much as 30 percent. What’s more, the risk of developing plaque stayed high even after a woman was off birth control pills for several years. This side-effect could put birth control pill users at a higher risk of heart attack and strokes for most of their lives.
Still, advocates for the birth control pill insist that neither of these studies should worry birth control pill users. They insist that the Belgian study was too small to draw any concrete conclusions. And because the birth control pill’s cervical cancer risk appears to be reversible, they argue that the benefits of using the Pill far outweigh its drawbacks.