RT Journal Article SR Electronic T1 OP006/#489 Survival impact of ontogenetic surgery for newly diagnosed cervical cancer JF International Journal of Gynecologic Cancer JO Int J Gynecol Cancer FD BMJ Publishing Group Ltd SP A13 OP A13 DO 10.1136/ijgc-2021-IGCS.23 VO 31 IS Suppl 4 A1 Kim, U A1 Kim, D A1 Park, SJ A1 Lee, M A1 Chung, HH A1 Kim, J-W A1 Park, NH A1 Song, Y-S A1 Kim, HS YR 2021 UL http://ijgc.bmj.com/content/31/Suppl_4/A13.2.abstract AB Objectives To evaluate the survival impact of ontogenetic surgery for stage IB1-IVB cervical cancer.Methods We prospectively enrolled patients with stage IB1-IVB cervical cancer (NCT02986568) for patients treated with total mesometrial resection (TMMR) or laterally extended endopelvic resection (LEER) from 2016 to 2020, who received adjuvant chemotherapy if resection margin was positive or positive pelvic lymph nodes ≥2 or positive para-aortic lymph node metastasis. For historical comparison, a retrospective cohort of patients who underwent standard treatment was gathered from 2010 to 2020. Clinico-pathologic characteristics, progression-free survival (PFS), and overall survival (OS) were compared between the prospective and retrospective cohorts.Results A total of 46 patients underwent TMMR or LEER in the prospective cohort and 207 patients received standard treatment in the retrospective cohort. Clinico-pathologic characteristics were equally balanced in both cohorts. In terms of survival analysis, ontogenetic surgery showed worse PFS (mean, 53.08 vs 88.3 mons, p=0.003) and no differences in OS. In subgroup analysis, stage IB1-IIA2 patients did not show differences in survival, whereas stage IIB-IVB patients showed worse PFS (mean, 30.9 vs. 40.3 mons, p=0.015) and no difference in OS. In multivariate analysis, ontogenetic surgery was associated with an increase of recurrence (HR, 3.55; 95% CI, 1.34–9.39)Conclusions Ontogenetic surgery was associated with increased recurrence in locally advanced cervical cancer despite its similar efficacy to standard treatment in early-stage disease. Thus, we have stopped the recruitment of patients with locally advanced cervical cancer for ontogenetic surgery for considering this harmful effect.