ESTRO 38 Abstract book

S816 ESTRO 38

at least 5 years. Half (55.5%) were current or ex-smokers. Squamous carcinoma (76.7%) was the most common histologic type (adenocarcinoma 16.4%, adenosquamous 1.4%). Clinical stage of the primary was distributed as: 30.1% IB, 11.0% IIA, 35.6% IIB, 3.4% IIIA, 15.8% IIIB, 3.4% IVA (n=1 missing). 63% had pelvic and/or para-aortic (PA) nodal involvement; 7.5% had clinical and/or radiological distant disease. Over 10% had another primary cancer diagnosis: n=7 (lymphoma, melanoma, sarcoma, breast, myelodysplastic syndrome) prior to, 2 (vulva, thyroid) concurrent with, and 6 (non-small cell lung, breast, vagina, bladder) after CC treatment. Most (n=125; 85.6%) had conventional chemoRT (pelvic±PA external beam RT with weekly cisplatin, and intracavitary±interstitial BT boost). N=14 received no chemotherapy; n=6, neoadjuvant±concurrent; n=1, concurrent+adjuvant. Four had BT only. Another 4 were treated after curative surgery was abandoned due to disease extent. An additional 11 had pelvic surgery: 1 pre-RT (nodal debulking), 1 post-BT (hysterectomy), 9 during follow-up (FU) (7 for salvage). Median FU was 28.5 months [3 - 54], with 2y-OS of 76.8% and CSS of 77.9%. By clinical stage, 2y-OS was 85.2% (IB), 82.5% (IIA/B), 55.3% (IIIA/B), 44.4% (IVA/B) and was statistically significant (p=0.001); this did not differ by nodal status. Those living < 50 km away fared worse, with 2y-OS of 71.4%, compared to 83.8% for those further away (p=0.054). Age and year of diagnosis had no appreciable effect. Conclusion In a heterogeneous CC cohort receiving primary RT/BT within a large integrated health system, outcomes are aligned with international reports. Mitigatable risk factors remain, as unrealized opportunities to optimize health outcomes in this population. EP-1508 EQD2 and overall treatment time as prognostic factors in cervical cancer treated with definitive CRT S.I. Perez Alvarez 1 , G.E. Trejo Durán 1 , J.C. Rodriguez Rosas 1 , C.H. Flores Balcazar 1 , J. Zamora Moreno 1 , G.B. Santiago Concha 1 , A. Mota García 1 1 Instituto Nacional de Cancerología, Radiation Oncology, Mexico City, Mexico Purpose or Objective Studies in cervical cancer treated with definitive (chemo)radiotherapy (dC(RT)) had reported the prognostic impact of hemoglobin before and during treatment, clinical response (CR), overall treatment time (OTT) and equivalent dose in 2Gy fractions (EQD2). We reported overall (OS) and disease free (DFS) survival by hemoglobin (Hb, cut-off 10 and 12g/dL), CR (complete or persistence), OTT (cut-off 52 and 56 days) and EQD2 (cut- Retrospective analysis of 898 patients with cervical cancer clinical stage I-IVA treated with complete dRT or dCRT from 2013 to 2017 at a single institution. Survival rates were calculated with Kaplan-Meier analysis and groups compared with log rank test. Results More than a half were stage IIB, and 93.8% were treated with CRT (table 1). After treatment, response in 622 patients was complete (69.5%), in 172 stable/partial (19.1%) and in 104 progression (11.6%). With a median follow-up of 22 months (2-76), 317 patients recur or progress (35.3%) with a median time to recurrence of 11 months (1-50). At last follow-up, 69.3% were alive and 30.7% died. off 75, 80 and 85Gy). Material and Methods

For all patients included 5-year OS was 51.2%. OS was significantly better within the first 4 years after treatment in patients with Hb before treatment ≥10g⁄dL (44% vs 30.2%, p<0.001) and ≥12g/dL (58% vs 41.9%, p=0.016). 5- year OS was better with complete CR (66.2% vs 2.3%); EQD2 ≥75Gy (61.5% vs 14.7%, p<0.0001), ≥80Gy (60.8% vs 27.6%, p<0.0001) and ≥85Gy (p=0.011); OTT ≤56 days (62.1% vs 53.7%, p=0.018) and ≤52 days (44.6% vs 50%, p=0.17). Patients with OTT ≤56 days and EQD2 ≥80Gy had a 5-year OS of 78.9% (vs 43.7%, p<0.0001). For all patients 5-year DFS was 50%. DFS was significantly better within the first 4 years after treatment in patients with Hb before treatment ≥10g⁄dL (66.7% vs 35.9%, p<0.0001) and ≥12g/dL (65.1% vs 48.1%, p<0.005). 5-year OS was better with complete CR (63.6% vs 0%, p<0.0001); EQD2 ≥75Gy (59.9% vs 24%, p<0.0001), ≥80Gy (58.4% vs 41.7%, p<0.001) and ≥85Gy (54.3% vs 53.8%, p=0.099); OTT ≤56 days (62.3% vs 52.5%, p=0.003) and ≤52 days (63.2% vs 53.6%, p=0.26). Patients with OTT ≤56 days and EQD2 ≥80Gy had a 5-year OS of 65.8% (vs 46.5%, p<0.0001).

In univariate analysis, histological differentiation, Hb (≥10 and ≥12g/dL) before and during treatment, pelvic lymph nodes, concurrent CRT, EQD2 (≥75, ≥80 and ≥85Gy), OTT (≤56 and ≤52 days) and CR showed significance for OS and DFS. Conclusion Different factors impact negatively the oncologic outcomes. Hemoglobin, OTT and EQD2 are modifiable factors that must be considered for the treatment of patients with cervical cancer to achieve better oncological outcomes. Reducing OTT to ≤52 days and maintaining total