Certain oral contraceptives can increase the risk of breast cancer in women, says a study.
The findings, reported in the latest issue of Cancer Research, revealed the hidden risks associated with consuming birth control pills with high doses of oestrogen.
In the study, women who consumed the high-oestrogen contraceptive pills in the recent past had 50 percent increased risk of breast cancer than women who never used them.
"Our results suggest that use of contemporary oral contraceptives in the past year is associated with an increased breast cancer risk relative to never or former oral contraceptive use, and that this risk may vary by oral contraceptive formulation," Dr Elisabeth F Beaber, a staff scientist in the Public Health Sciences Division of Fred Hutchinson Cancer Research Centre in Seattle, Washington, said in a news release.
Researchers looked at 1,102 breast cancer patients and compared them to 21,952 controls. Oestrogen content in the pills- no matter high or moderate- found to be risky. While pills with a high dose oestrogen had a 2.7 fold risk, moderate dose oestrogen pills was associated with 1.6 fold cancer risk.
The study also identified risks associated with certain other formulations used in the pills including ethynodiol diacetate (2.6 fold) and triphasic combination pills with 0.75 mg norethindrone (3.1 fold). Birth control pills with low oestrogen levels were found to be safe.
"Our results require confirmation and should be interpreted cautiously," Beaber said. "Breast cancer is rare among young women and there are numerous established health benefits associated with oral contraceptive use that must be considered. In addition, prior studies suggest that the increased risk associated with recent oral contraceptive use declines after stopping oral contraceptives."
The findings come at a time when breast cancer, one of the leading causes of cancer deaths in the world, claims millions of lives every year. It is estimated that the deadly disease will claim nearly 2.1 million lives every year by 2030.
Research conducted to combat the deadly disease have linked it to a wide range of lifestyle factors including night shifts, alcohol consumption, smoking, radiation exposure, in vitro fertilization (IVF) treatment, pregnancy diet, fatty food consumption in puberty, high cholesterol, high blood pressure drugs, red meat, stylish bras and moles.
Birth control pills, though widely promoted to prevent teen pregnancy, have also been a source of concern.
In April 2012, a Leicester teenage girl suffered two strokes after she took the contraceptive pills. Gemma Hill vomited blood a few weeks after taking the contraceptive pill for period pains. Four days after the incident she had a severe stroke.
Medical experts identified a blood clot on the girl's brain as the main reason behind the brain attack. The blood clot was a side effect of the contraceptive pill that she had taken. The stroke severely affected Gemma's memory, vision as well as ability to walk and talk. The first stroke was followed by another, two months later when she was undergoing a treatment.
In November last year, a study presented at the American Academy of Ophthalmology linked long-term use of birth control pills to glaucoma.