Stages I to II WHO 2003-Defined Low-Grade Endometrial Stromal Sarcoma How Much Primary Therapy Is Needed and How Little Is Enough?

Objective: Before 2003, invasive endometrial stromal sarcomas (ESS) were classified into 2 categories, low-grade and high-grade ESS, according to the mitotic index. In 2003, the World Health Organization changed the definition and the diagnostic criteria. Before 2003, 20% to 35% low-grade ESS recurred, but WHO 2003-defined low-grade ESS has 10 years' recurrence rates of less than 10%. With so few recurrences, the balance between treatment guaranteeing cure and overtreatment ("not too little'' or "too much'') becomes increasingly important. However, primary treatment practices range from limited surgery only to extensive surgery combined with adjuvant chemotherapy and radiotherapy. We focused on the primary treatment of early-stage WHO 2003-defined low-grade ESS. Methods: We evaluated the effect of different therapeutic strategies in 57 patients with International Federation of Gynecology and Obstetrics 2009 stages I to II expert-reviewed WHO 2003-defined low-grade ESS treated at a single institution between 1992 and 2007. Results: The patients' median age was 43 years (range, 19-63 years). After 68 months' median follow-up (range, 17-140 months), recurrence and mortality rates were 9% and 2%, respectively. The patients with WHO 2003-defined low-grade ESS with ovary-preserving primary surgery had a much higher recurrence rate (75%) than those without (2%; P < 0.0001). Lymphadenectomy, radical abdominal hysterectomy, and omentectomy did not influence survival. Ten patients refused chemotherapy. With univariate analysis, multiple-agent chemotherapy improved the prognosis (P = 0.02) With multivariate analysis, only ovary preservation-or-not surgery had independent prognostic value. Conclusions: In International Federation of Gynecology and Obstetrics 2009 stage I to stage II WHO 2003-defined low-grade ESS, total abdominal hysterectomy with bilateral salpingo-oophorectomy is sufficient surgery, but ovary-preserving primary surgery increases the risk of recurrence. More extensive surgical procedures than total abdominal hysterectomy with bilateral salpingo-oophorectomy do not improve prognosis in early-stage WHO 2003-defined low-grade ESS. Chemotherapy may improve progression-free survival in early-stage low-grade ESS, but a large sample size is needed to confirm this.