[1] Univ Southern Calif, Div Gynecol Oncol, Dept Obstet & Gynecol, Los Angeles, CA 90007 USA
[2] Northwestern Univ, Dept Obstet & Gynecol, Div Gynecol Oncol, Chicago, IL 60611 USA
[3] Northwestern Univ, Robert H Lurie Comprehens Canc Ctr, Chicago, IL 60611 USA
[4] Inst Publ Hlth Med, Surg Outcomes & Qual Improvement Ctr, Chicago, IL USA