Contraceptive pills may prevent cancer

Recent research shows that using oral contraceptives (OCs) may protect against ovarian cancer. OCs contain the female hormones – oestrogen and progesterone. Oral contraceptives or birth control pills, are the most common form of contraception. Females have to take these tablets everyday for 21-25 days in a month, after which withdrawl bleeding results in menstruation. The relationship between the progesterone and oestrogen potency in combination OCs and the risk of developing ovarian cancer was investigated.Researchers from the Duke University Medical Centre studied 390 cases with epithelial ovarian cancer and 2865 control subjects, between 20 and 54 years of age. These included women who used OC combination pills (containing both an oestrogen and a progesterone for 21 days each month). Women who did not know if they had ever used OCs for 3 or more consecutive months, those who had used an unknown type of OC pill and women who used progesterone-only OCs, were excluded from the analysis.Up to seven OC cycles were recorded among the users. Each OC episode was categorized according to progesterone and oestrogen potency, either low or high, according to a definite scheme. Users of low-progesterone/high-oestrogen potency formulations and low-progesterone/low-oestrogen potency formulations had a higher risk of ovarian cancer than users of high-progesterone/high-oestrogen potency formulation. Low-progesterone potency OC formulations were linked with a much higher risk of cancer than high-progesterone potency formulations. This link was seen even among users of short duration. The combination OC formulations with high-progesterone potency appear to be associated with a greater reduction in ovarian cancer risk than those with low-progesterone potency. Biologic effects related to the progesterone component in OCs may be responsible for their protective effect. In addition, the women diagnosed with ovarian cancer had fewer pregnancies and were more likely to report a family history of breast or ovarian cancer.