Study: Oral contraceptives may reduce overall cancer risk
by Daniel Beaulieu
According to data from a study published in the BMJ, oral contraceptives do not increase the overall risk of developing cancer, and may reduce the risk by as much as 12 percent in women who take the drug for less than eight years. However, the results also demonstrated that women who take oral contraceptives for more than eight years have a higher risk of developing certain types of cancer.
As part of the study, researchers examined 36 years of data from 46 000 women who enrolled in the Royal College of General Practitioners’ oral contraception study in 1968. About half the women in the study took oral contraceptives, for an average duration of 44 months. In the study’s main dataset, the findings showed that compared with those who had never taken oral contraceptives, those who took the drugs had significantly lower rates of cancer of the large bowel, uterine body and ovaries, among other malignancies.
Additionally, the results suggested that the relative risk reduction for ovarian and uterine body cancers persists "for many years after stopping oral contraception, perhaps more than 15 years," the researchers noted. Nonetheless, the findings also showed that women who took oral contraceptives for more than eight years experienced a 22-percent greater risk of developing cancer, particularly cervical and central nervous system cancers.
"The long-term cancer benefits might counter the short-term harmful ones if they persist into the age when most malignancies become common in women, 50 years or more,” the researchers suggested. However, lead author Philip Hannaford cautioned that he would not advise women to take oral contraceptives specifically to cut their cancer risk as they grow older. "It seems too simplistic to say everyone should go on the Pill."