Last year, we wrote that a study published in the American Journal of Epidemiology concluded that birth control pill use is linked with an increased risk of <"http://www.yourlawyer.com/topics/overview/breast_cancer">breast cancer. Now, Slate is reporting that, also last year, a study of over 50,000 African-American women revealed a 65-percent increase in a specific, and highly aggressive form of breast cancer in women who ever took a birth-control pill, said Slate.
The study was led by Boston University epidemiologist Lynn Rosenberg, who also found that the risk doubled in women who used a birth-control pill in the prior five years and had taken it in excess of 10 years, noted Slate. The pill, said Slate, celebrates its 50th anniversary this year. While commemorative pieces have celebrated the pillâ€™s virtues through the years, including an MSN.com piece in which it stated “taking the pill has no impact on breast cancer risk,” some research disagrees.
Rosenberg chose the African American demographic because of the dearth of research into that group, noting that this group tends to suffer from a significantly higher rate of so-called “triple negative” breast cancer, said Slate. This is a rare strain with genes that appear to be unresponsive to standard treatment, including tamoxifen, and which presents with the highest, quickest mortality rates. Rosenbergâ€™s research linked these virulent cancers to the pill, as did other studies involving women of various races, including research conducted in New England, South Carolina, New York, and Scandinavia.
A prior study used information from the Case-Control Surveillance Study to look at birth control pill use and breast cancer risk in women diagnosed with breast cancer between 1993 and 2007, said Reuters. The study looked at race and tumor hormone receptors and involved over 2600 women, 907 with breast cancer and 1771 without.
The team found that women who had taken oral contraceptives for at least one year experienced a 50 percent greater chance of developing breast cancer over women who took the pills for less time or who had never taken the pills, said Reuters. Also, greater duration, use in the past decade, and being of black ethnicity, all seemed to raise the incidence of breast cancer; hormone receptor status did not affect the link.
Estrogens, said the Denver Wellness Examiner last year, cause cells to multiply and divide, noting that the more a cell divides, the greater the chance for cancer to develop. The National Cancer Institute (NCI) explained that two types of oral contraceptives are available in the United States. The combined pill contains two artificial versions of the natural female hormones estrogen and progesterone, similar to what the ovaries normally produce. The minipill only contains a type of progesterone.
Estrogen stimulates the growth and development of the uterus at puberty, causes the endometrium, or inner uterine lining, to thicken during the first half of the menstrual cycle, and affects breast tissue throughout a womanâ€™s lifetime, specifically from puberty to menopause. Progesterone is produced during the last half of the menstrual cycle; prepares the endometrium to receive the egg; and if an egg is fertilized, continues producing to prevent further egg release. It is because of this that progesterone is called, said the NCI, the â€œpregnancy-supportingâ€ hormone.
In 2003, an NCI-sponsored study examined risk factors for breast cancer among women ages 20 to 34 versus women ages 35 to 54 and looked at women diagnosed with breast cancer and womenâ€™s oral contraceptive use. The study found that breast cancer risk was highest in women who used oral contraceptives within five years prior to diagnosis, with women in the younger group being most susceptible.