RT Journal Article SR Electronic T1 EP322 The influence of modulated electrohyperthermia (mEHT) on tumor cell apoptosis in iib−iva cervical cancer patients with deep parametrial invasion JF International Journal of Gynecologic Cancer JO Int J Gynecol Cancer FD BMJ Publishing Group Ltd SP A230 OP A230 DO 10.1136/ijgc-2019-ESGO.383 VO 29 IS Suppl 4 A1 Kaskulova, M A1 Kreynina, Y A1 Shevchenko, L A1 Solodky, V A1 Bozhenko, V A1 Kudinova, E YR 2019 UL http://ijgc.bmj.com/content/29/Suppl_4/A230.2.abstract AB Introduction/Background Incomplete response, associated with unfavorable prognosis after standard chemoradiation with weekly Cisplatinum 40 mg/m2 one observes in more, than 35% of advanced cervical cancer (ACC) patients with deep (≥ half uni- or bilateral) parametrial invasion. mEHT shows to overcome therapy resistance in these pts in pilot study but the mechanism of its input to cell damage effect of radiation and cytotoxic drugs was unclear. mEHT influence on cell apoptosis in ACC pts was evaluated.Methodology Tumor samples were taken from 35 pts T2b−T4a ACC, parametrial invasion >1/2 (unilateral − in 14 (40%), bilateral − in 21 (40%) pts.), before the treatment and twice during conformal external beam radiotherapy (3D−CRT, IMRT, Dynamic Arc), in 2Gy, 46−48 Gy for pelvic or extended paraaortic fields, Cisplatin 40 mgm2 or Carboplatinum AUC2 weekly, with mEHT before irradiation in 18 of them (EHY-2000 device, 60–90‘ 3 t/week, 90–120 Wt, 10−13 fractions per course. 20−gene panel was used (Ki67, STK15, CCNB1,PTEN,CCND1,MYC,P16NK4a,MYBL2,DCL2,BAX,BAG,NDRG1,BIRC5,TERT,CerbB2, GRB7,CTSL2,CD68).Results In mEHT group objective response (RECIST 2.0) was reached in all 18 pts: CR − in 13 (73,2%) pts, PR >80% − in 5 (27,8%). In chemoradiation group (17 pts): CR − in 4 (22,9%), PR −1 CR − in 4 (23,5%) pts, PR- in 8 (47%), stable - 4 (23,5%) больныx, progression (local+paraaortic LN and liver) - 2(11,7%). Apoptosis induction was associated with complete response in both groups, significantly higher (p=0,03−0,043) in mEHT group.Conclusion mEHT significantly improves the response to chemoradiation in ACC patients with deep parametrial invasion. Gene alteration level at 30Gy has a predictive value.Disclosure Nothing to disclose.