The link between breast cancer and birth control or contraceptive pills has been debated over the years, especially with the increasing incidence of the deadly disease among women worldwide. Apparently, a recent study in the Journal of Cancer Research indicates that the varying formulations in these pills may be the culprit.
The study, funded by the National Cancer Institute, says that women who used oral contraceptives with a high dose of estrogen content plus other formulations showed an increased possibility on the development of breast cancer as compared to others who used pills with different formulations.
"Our results suggest that use of contemporary oral contraceptives [birth control pills] 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," study lead author, Elisabeth F. Beaber, PhD, MPH, says in a statement.
To come up with the study, the researchers gathered 1,102 women who are 20 to 49 years old and are diagnosed with invasive breast cancer since 1990 to 2009. They discovered that the current use of birth control pills indeed increased by 50 percent the risk of such cancer as opposed to having never used or formerly used the pills.
The researchers reveal that oral contraceptives with a high dosage of estrogen content intensified the breast cancer risk by 2.7 fold, while moderate content of estrogen intensified the risk by 1.6 fold. Those with ethynodiol diacetate content upped the risk by 2.6 fold, while triphasic combination contraceptives with an average content of 0.75 milligrams norethindrone increased risk by 3.1 fold. Pills with low dosage of estrogen didn’t intensify the risk for such cancer.
Along with her colleagues, Beaber made use of electronic pharmacy records in the information gathering of birth control pills or oral contraceptives use, including the name of the drug, the dosage and the duration of use, as compared to previous studies conducted that solely depended on self-report or recall by women that may bring about biased results.
Beaber, who is a staff scientist at the Fred Hutchinson Cancer Research Center’s Public Health Sciences Division in Seattle, Washington, warns just the same that the findings of the study require cautious interpretation and further confirmation.
"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,” says Beaber.
The relationship between breast cancer and oral contraceptives can be read in the study titled "Recent Oral Contraceptive Use by Formulation and Breast Cancer Risk among Women 20 to 49 Years of Age," which appeared in the said official journal of American Association for Cancer Research available online.
