Predominance of early endometrial cancers after long-term estrogen use
B. S. Hulka, D. G. Kaufman, W. C. Fowler Jr, R. C. Grimson and B. G. Greenberg
Clinical stage and pathological characteristics of endometrial cancer cases
were related to several aspects of estrogen prescribing. In comparing 256
cases with 321 community control subjects, estrogen use of less than 3 1/2
years' duration did not increase the risk of endometrial cancer for any
stage, grade, histological type, or extent of ivasion. With long-term
estrogen use (3 1/2 years or more), relative risks were significantly
increased (5.2 to 7.6) for the early cancers--those clinically stage IA,
histologically grade 1, and invading the endometrium only. These increases
were seen with both high-dose (greater than 0.625 mg) and low-dose (less
than or equal to 0.625 mg) preparations. Risks were only minimally
increased for the more advanced cancers. However, long-duration estrogen
use did produce an increased risk of advanced cancer when administration
was continuous rather than cyclic.
