ESTRO 2023 - Abstract Book

S1088

Digital Posters

ESTRO 2023

Conclusion A multimodal pre-treatment workup, including CT scan, FDG-PET/CT scan and laparoscopy, should be searched to improve clinical endpoints in borderline resectable and locally advanced unresectable PDAC.

PO-1357 Real life results of CROSS: the impact in overall survival and progression free survival.

R. Matias 1 , A. Pires 1 , S. Costa 1 , F. Fernandes 1 , S. Zorro 1 , J. Lima 1 , S. Sarandão 1 , D. Gomes 1 , J. Rodrigues 2 , O. Sousa 1

1 Instituto Português de Oncologia do Porto Francisco Gentil, EPE, Radiotherapy, Porto, Portugal; 2 Instituto Português de Oncologia do Porto Francisco Gentil, EPE, Epidemiology, Porto, Portugal Purpose or Objective The CROSS Trial showed that patients (pts) with oesophagus/gastro-oesophageal junction (GOJ) tumours submitted to neoadjuvant CRT followed by surgery (vs. surgery alone) had improved long-term OS and PFS, regardless of cell histology, which became the standard of care. We aimed to analyze our institutional experience with CROSS protocol and evaluate OS and PFS. Materials and Methods Pts with clinically resectable, locally advanced oesophagus or GOJ (Sievert I-II) tumours, clinical stage T1N1M0 or T2-4N0 1M0 (TNM 8th edition) were retrospectively recorded. Pts treated with CROSS regimen, consisting of neoadjuvant CRT (5 cycles weekly IV carboplatin and paclitaxel with 41.4Gy/23 fractions, 5 days/week) followed by surgery (SX) were included. Results From Sep/2013 to Nov/2019, a total of 90 consecutive pts were reviewed (median age 61 years old, 91.1% males), all with PS 0-1. The most prevalent cell histology was squamous cell carcinoma (SCC, 75.6%), followed by adenocarcinoma (AC, 23.3%) and 1.1% other. 64 pts (71.1%) had disease in the thoracic oesophagus, and the remaining in GOJ. 62 pts (68.9%) completed all 5 cycles of chemotherapy (CTX), and 28 (31.1%) had dose reduction/suspension either due to cytotoxicity or logistical constraints. All pts except 2 completed RT. Most patients (n=84, 93.3%) proceed to radical SX. Of the remaining 6 pts, 3 (3.3%) had irresectable disease at SX, 2 (2.2%) had no clinical conditions for SX, and 1 (1.1%) had disease progression before SX. From the 84 surgical resections, 35 (41.7%) had pCR. The median follow-up (FUP) was 43.9 months. Of the 84 pts that completed CRT and SX, 23 (27.4%) had recurrence: 60.9% local and distant, 21.7% local and 17.4% at the distance. At the time of analysis, 45 pts were alive (42 without evidence of disease), of the others: 2 died in postoperative hospital stay, 5 within 90 days postoperatively, 18 without disease and the remaining with disease. The overall median OS was 69.0 months (95% CI 42.2 - 95.9), and both SCC and AC had a median OS of 69.0 months (p=0.921). The OS at 1, 2 and 3 years were 87.8%, 70.0% and 62.2%, respectively. The overall median PFS was not reached, even when analyzed by histologic subtype. The PFS at 1, 2 and 3 years were 94.8%, 81.1% and 72.0%, respectively. On univariate analysis, pts who completed the 5 cycles vs. ≤ 4 cycles of CTX and pts with pCR had better OS (HR: 0.46, 95% CI 0.25-0.86; HR: 0.48, 95% CI 0.24 - 0.95, respectively) and PFS (HR: 0.36, 95% CI 0.16-0.85; HR: 0.41, 95% CI 0.17 - 0.99). Toxicity G ≥ 3 had no influence in OS but had impact on PFS (HR 3.16; 95% CI 1.15 – 9.64). This could be due to the interruption of CTX in some pts. On multivariate analysis neither variable restrain significance. Conclusion Grade ≥ 3 toxicity had a negative impact only on PFS. Additionally, pts who did not complete 5 cycles of CTX and pts graded with no pCR had worst rates both on OS and PFS. Compared to the CROSS results, we report better OS and PFS rates overall and considering histology.