Your search found 2 Results
AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY. 1992 Oct; 167(4 Pt 2):1171-6.The largest case control study on the association between oral contraceptive (OC) use and cancer is the US Cancer and Steroid Hormone (CASH) study. Since it did not use hospital-based patients as controls, it eliminated some biases. Since OCs suppress ovulation and suppressed ovulation is linked with reduced risk of ovarian cancer, scientists believe OCs may reduce this cancer risk. The CASH study shows that OC use indeed decreases the risk of ovarian cancer 40% (relative risk [RR]=.6 and this protection lasts for more than 10 years after OC discontinuation. Protection increases with duration of OC use (<1 year RR=.6 and >10 years RR=.2). Estrogenic stimulation of the endometrium without ample progestational protection causes endometrial cancer. Thus combined OCs which have estrogen and progestin components should reduce the risk of endometrial cancer. The CASH study reveals OC use for at least 12 months reduces this risk 50%. OCs have a protective effect for at least 15 years after stopping OC use. In addition, UK national mortality data show OC use caused the decline in ovarian cancer mortality and a 40% decrease in endometrial cancer mortality over the last 20 years. A WHO 7-county case control study indicates that OC users in developing countries have the same protective effect against ovarian and endometrial cancer as those in developed countries. Studies of OC use and cervical cancer have had conflicting results due to 3 biases: cervical cancer is associated with sexual behavior and is therefore a sexually transmitted disease; detection bias. A study in Costa Rica conducted by CDC study has addressed the 1st and 3rd biases. It found no increased risk of invasive cervical cancer or carcinoma in situ with OC use. Studies of OC use and breast cancer have also had conflicting results, but the data clearly indicate that OC use does not increase the overall risk of breast cancer. In fact, OC benefits surpass breast cancer risks.
A preliminary pharmacokinetic and pharmacodynamic evaluation of depot-medroxyprogesterone acetate and norethisterone oenanthate.
Fertility and Sterility. 1980 Aug; 34(2):131-9.2 populations attending WHO centers, one in Sweden and one in India, participated in a comparative, pilot trial of 2 increasingly popular injectable progestin-only female contraceptives, Depo-Provera and Norigest. The purpose of the study was to assess the pharmacokinetic and pharmacodynamic properties of the 2 formulations (depot medroxyprogesterone acetate and norethisterone enanthate). Differences were found between Swedish women and Indian women in their reactions to the 2 drugs: 1) Norigest was detectable in blood samples a significantly shorter time after injection of the agent in Indian women than in Swedish women; this difference was not apparent with Depo-Provera. 2) Although there was no difference at the 2 centers in the time of ovulation return for subjects receiving Norigest, 0 of 4 Swedish women ovulated more than 156 days after Depo-Provera injection, whereas all 4 Indian women ovulated within 73 days of Depo-Provera injection; in the Swedish women, the levels of medroxyprogesterone were undetectable at time of return to ovulation, whereas Indian women had levels of .6 ng/ml when ovulation resumed. 3) In both cultures, Depo-Provera users had significantly more episodes of bleeding and spotting than Norigest users. This preliminary report emphasizes the variety of responses possible to injection of different contraceptive progestins among various populations and points to the need for further culturally comparative studies.