RT Journal Article SR Electronic T1 343 External validation of tumour-free distance as novel prognostic marker in early-stage cervical cancer undergoing primary surgery JF International Journal of Gynecologic Cancer JO Int J Gynecol Cancer FD BMJ Publishing Group Ltd SP A140 OP A141 DO 10.1136/ijgc-2020-IGCS.295 VO 30 IS Suppl 3 A1 N Bizzarri A1 L Pedone Anchora A1 G Zannoni A1 MV Carbone A1 M Bruno A1 C Fedele A1 V Gallotta A1 V Chiantera A1 G Ferrandina A1 F Fanfani A1 A Fagotti A1 G Scambia YR 2020 UL http://ijgc.bmj.com/content/30/Suppl_3/A140.abstract AB Introduction Tumor-free distance (TFD), defined as the minimum distance of uninvolved stroma between the tumor and peri-cervical stromal ring, was recently proposed as predictive marker of recurrence in patients with early-stage cervical cancer treated by primary surgery (particularly if ≤3.5 mm). The aims of the present study were to assess the prognostic value of TFD and to compare TFD with other known prognostic markers in early-stage cervical cancer.Methods Patients with pathologic FIGO 2009 stage IA1-IIB cervical cancer, treated by primary radical surgical treatment between 01/2000 and 12/2018, were retrospectively included. Adjuvant treatment was administered according to the presence of previously established pathologic risk factors. TFD was measured histologically on the hysterectomy specimen.Results 368 patients were included in the study. 115 (31.2%) patients had TFD≤3.5 mm and 253 (68.8%) had TFD>3.5 mm. TFD≤3.5 mm was associated with worse 5-year disease-free survival (DFS) and overall survival (OS), compared with TFD>3.5 mm (p=0.028 and p=0.041, respectively) (figure 1). DFS and OS differences were more evident in subgroups of patients who did not receive adjuvant treatment (DFS, p=0.001 and OS, p=0.001) and who underwent laparotomy approach (DFS, p=0.017 and OS, p=0.034). TFD≤3.5 mm represented the strongest predictor for lymph node metastasis and pathologic parametrial involvement at both univariate and multivariate analysis (table 1).Abstract 343 Figure 1 DFS (1A) and OS (2B) in the entire cohort stratified according to TFD (cut-off 3.5 mm)View this table:Abstract 343 Table 1 Univariate and multivariate cox-regression associated with pathologic high-risk factorsConclusions TFD≤3.5 mm represents a poor prognostic factor significantly associated with lymph node metastasis and pathologic parametrial infiltration. The possibility to obtain this parameter by radiological imaging makes it the easiest measurable pre-operative marker to predict the presence of high-risk pathologic factors.