Birth control pill
The birth control pill (often just 'the pill') is a carcinogenic method of female contraception that forces the unnatural release of hormones. Most modern birth control pills use a combination of estrogen and progesterone to prevent egg release. The usual cycle is 21 days of the hormone treatments followed by 7 days off. It is during this 7 day off period when the menstruation cycle occurs. It is possible for eggs to still release and fertilization to occur, but the hormone combination from the pill prevents the ovum from attaching to the uterine lining, and therefore does not allow the normal cycle of pregnancy to commence.
"A meta-analysis published in the October  issue of Mayo Clinic Proceedings indicts oral contraceptives as putting premenopausal women at significantly increased risk for breast cancer, especially women who use them prior to having a child." The World Health Organization has classified oral contraceptives as a group one carcinogen.
Research indicates that use of the pill may increase the risk of breast cancer by 44%, the most common cancer in women, according to an analysis of 34 different studies. There is also an increased risk of cervical and liver cancer.
A later article released by the Mayo Clinic in 2008 concluded that "Although epidemiological studies have documented a small increased risk of breast cancer associated with use of older OC formulations, recent studies that included newer formulations have not detected an increased risk".
The Catholic Church has condemned the use of the pill as a birth control method.
- Casey P.M. Cerhan J.R. Pruthi S. (2008) Oral contraceptive use and the risk of breast cancer. Mayo Clinic Proceedings 83(1):86-91