Endometrial cancer: high-potency OCPs in heavier women protective.(Gynecology)

SAN DIEGO -- All oral contraceptives offer some protection against endometrial cancer, but heavier women get better protection from pills that contain high-potency, rather than low potency, progestins, Dr. Larry Maxwell reported at the annual meeting of the Society of Gynecologic Oncologists.

"When we stratified our results according to subjects' BMI [body mass index] ... we found that high potency OCPs [oral contraceptive pills] in heavier women offer almost a 70% greater risk reduction than low-potency OCPs, which is pretty profound." said Dr. Maxwell of Walter Reed Army Medical Center, Washington.

The study was a reanalysis of a subgroup in the Cancer and Steroid Hormone Study (CASH), which was published in 1983.

Dr. Maxwell and his colleagues used the CASH data to examine the relationship between progestin and estrogen potency in combination OCPs in 434 women with endometrial cancer and 2,557 controls.

Non-OCP users were defined as those who had used OCPs for less than 12 months. OCP users were defined as having used OCPs for at least 12 months and were divided into four cat egories by type of pill use: high estrogen and progestin; high estrogen/low progestin; low estrogen and progestin; and low estrogen high progestin.

Overall, the difference between estrogen and progestin potencies had no impact on endometrial cancer incidence. Compared with women who didn't use OCs, however, those using a high-potency progestin OC had an odds ratio of 0.20 for endometrial cancer while women using low-potency progestin OCs had an odds ratio of 0.39.

In women with a BMI at or above the median, which was 22 in the CASH study, high-progestin combinations were more protective than ...