Oral contraceptive pills raise risk of breast cancer 9.5 times: AIIMS study
Use of oral contraceptive pills in the long term can cause breast cancer, says a research published in the Indian Journal of Cancer on Wednesday. The study, conducted by researchers at the All India Institute of Medical Sciences (AIIMS) in New Delhi, also says that other factors like early menarche (the first menstrual cycle), late marriage or late menopause can cause the cancer.
The researchers have concluded that “the risk of breast cancer was 9.5 times higher in women having a history of consumption of oral contraceptive pills.”
In their study, the researchers A S Bhadoria, Umesh Kapil, N Sareen and P Singh, all from department of gastroenterology and human nutrition unit of AIIMS, said that breast cancer is caused by repeated exposure of breast cells to circulating ovarian hormones. Kapil said that the finding suggests strong relationship between long-term use of oral contraceptive pills and the disease.
In the study, spread over 2005-06, the researchers included total of 320 breast cancer patients and an equal number of matched control group. The patients were picked from the outpatient and hospital admissions of department of surgery and surgical oncology. The mean age of the patients was 45.5 years. Majority of the patients belonged to urban areas. All the patients were married and the majority of them were housewives. Around one-third of subjects were illiterate.
The study found that the mean age of menarche in breast cancer patients was 13.20, while the average age of the control group was 14.58 years. The patients were of higher age at the time of marriage as compared to the control group. They also had statistically higher mean age at last childbirth as compared to the control group. The patients underwent a significantly higher number of abortions (61.3 per cent) as compared to the control group (16.3 per cent). There was a statistically significant difference in the mean age of menopause of patients as compared to the control group with patients attaining menopause at a late age (49.38) as compared to members of the control group (47.89).
When asked about any special relation with morning after pills or any specific kind of pills and new finding, Kapil said there is substantial evidence against morning after pills in literature but it needs more research. In the present case, the research talks only about long term use of normal contraceptive pills, he said.
He, however, added that it is not an alarming situation, requiring urgent government intervention.
Previous studies on the subject have also shown similar results. Many clinical, animal and epidemiological studies carried out in the past have proved that breast cancer is a hormonally mediated disease. Several factors that influence hormonal status have been shown to be associated with the risk of breast cancer.
In 1996, Lancet, a British medical journal, published a paper on women who were taking oral contraceptives. They have a higher chance of getting the disease 10 years after stopping the consumption of pills, said the research finding.
Reproductive factors and breast cancer: A case-control study in tertiary care hospital of North India