Endometrial response to the use of a sequential oral contraceptive

Belgium is 1 of the few countries where sequential oral contraceptives are still commercially available. The authors investigated the endometrial effect of Ortho-Novum SQ (14 tablets of 100 mcg mestranol and 7 tablets of 100 mcg mestranol + 2 mg norethisterone) in 222 biopsy specimens obtained from 184 asymptomatic Caucasian women (mean +or- s.d, age and parity, 34.6 +or- 6.7 and 2.0 +or- 1.0, respectively) who had used this sequential OC during an average of 52.5 months. Notwithstanding predominantly longterm use of Ortho-Novum SQ, 43% of the tissue samples had normal proliferative or luteal endometrium. The data suggest a positive correlation between the endometrial response and the duration of pill use. No premalignant or malignant changes were found. In 15 of 24 subjects for whom multiple biopsy specimens were available, the histological picture was static; 7 showed regression and only in 2 were the changes progressive, although never more severe than minor 'class 2' lesions. These results, which are at variance with those reported for users of other sequential brands (mainly Oracon), suggest that prolonged use of Ortho-Novum SQ does not enhance the risk of endometrial cancer in premenopausal women having no additional risk factors for the development of this type of neoplasia.