PROTECTIVE EFFECT OF DEPOT-MEDROXYPROGESTERONE ACETATE ON SURGICALLY TREATED UTERINE LEIOMYOMAS - A MULTICENTER CASE-CONTROL STUDY

Objective To assess the protective effect of depot-medroxyprogesterone acetate (DMPA) on uterine leiomyomas. DMPA has been widely used in Th ailand for many years; uterine leiomyomas is the most common female tu mour. Design A multicentre hospital-based case-control study. Setting University and regional hospitals. Patients Cases were all newly diagn osed patients with pathologically proven diagnosis of uterine leiomyom as, who were admitted to eight hospitals in three regions of Thailand from January 1991 to June 1993. Three controls matched with cases by s ex, age within five years and date of admission within three months we re recruited. Main outcome measures Information on socio-demographic f actors, personal and family history, current disease, reproductive and contraceptive history was collected from cases and controls by interv iew. Results There were 910 cases and 2709 controls. After univariate and unconditional multiple logistic regression analysis, risk factors associated positively with uterine leiomyomas are tubal ligation, fami ly history of uterine leiomyomas, higher education, obesity and aborti on. in contrast, DMPA, use of oral contraceptives, higher parity and s moking are associated with a lower relative risk suggesting that they have a protective effect against uterine leiomyomas. This causative re lation is further strengthened by the strong duration-response relatio n between DMPA and uterine leiomyomas. This protection may persist for more than 10 years after the last dose. Conclusion We have demonstrat ed a strong, duration dependent protective effect of DMPA against uter ine leiomyomas.