Perioperative Chemotherapy Prolongs OS vs Neoadjuvant Chemoradiation in Esophageal Cancer

Perioperative chemotherapy with docetaxel, oxaliplatin, leucovorin, and 5-fluorouracil (FLOT protocol) led to a significant overall survival (OS) benefit vs neoadjuvant chemoradiation (CROSS protocol) in patients with resectable esophageal cancer, according to findings from the phase 3 ESOPEC trial (NCT02509286) presented during the 2024 ASCO Annual Meeting.¹

At a median follow-up of 55 months, patients in the intention-to-treat population who received the FLOT protocol (n = 221) achieved a median OS of 66 months (95% CI, 36-not evaluable [NE]) compared with 37 months (95% CI, 28-43) among those who were treated with the CROSS protocol (n = 217; HR, 0.70; 95% CI, 0.53-0.92; P = .012). The 3-year OS rates were 57.4% vs 50.7%, respectively, and the 5-year OS rates were 50.6% vs 38.7%, respectively.

Additionally, the median progression-free survival (PFS) was 38 months (95% CI, 21-NE) in the FLOT arm compared with 16 months (95% CI, 12-22) in the CROSS arm (HR, 0.66; 95% CI, 0.51-0.85; P = .001). The 3-year PFS rates were 51.6% vs 35.0%, respectively, and the 5-year PFS rates were 44.4% vs 30.9%, respectively.

“Many patients in the US and Europe are still treated with the CROSS radiochemotherapy protocol. Our study shows that patients with resectable esophageal cancer should have FLOT chemotherapy before and after the operation in order to optimize the chance of curing their tumors in the long term,” Jens Hoeppner, FAChirg, FACS, MD, the director of the Department of Surgery at University Medical Center, University of Bielefeld, in Detmold, Germany, stated in a press release.²

ESOPEC was a prospective multicenter study that enrolled patients with esophageal adenocarcinoma across 25 sites in Germany between February 2016 and April 2020. Eligible patients needed to be at least 18 years old, have received no prior abdominal or thoracic radiotherapy, have an ECOG performance status of 2 or less, and have adequate organ function. Patients were also required to have pretreatment stage cT1N+, M0 or cT2-4a, N0/+, M0 disease. The presence of squamous or other non-adenocarcinoma histology, gastric cancer, clinical stage cT1cN0 and cT4b disease, or metastatic disease excluded patients from enrollment.^1,3

Patients were randomly assigned 1:1 to receive either the FLOT or CROSS protocol. Those in the FLOT arm received repeated doses of 5-fluorouracil, leucovorin, oxaliplatin, and docetaxel every 2 weeks over 4 neoadjuvant cycles prior to surgery and 4 adjuvant cycles after surgery. In the CROSS arm, patients received neoadjuvant radiation therapy and concurrent chemotherapy with carboplatin and paclitaxel for 5 cycles in 5 weeks prior to surgery. Following neoadjuvant treatment, patients in both arms waited 4 to 6 weeks before proceeding to surgery.

The primary end point was OS. Secondary end points included PFS, recurrence-free survival, postoperative pathological stage, postoperative complications, and postsurgical quality of life.

At baseline, the mean age of patients in the FLOT and CROSS arms was 63.1 years (standard deviation [SD], 8.6) vs 62.6 years (SD, 9.8), respectively. Most patients in both arms were male (89.1% vs 89.4%), had clinical T-stage cT3-4 disease (79.1% vs 81.9%), and had clinical N-stage cN+ disease (77.8% vs 81.6%). Overall, 191 patients in the FLOT arm underwent surgery compared with 180 patients in the CROSS arm.

Additional findings from ESOPEC showed that the pathological complete remission rates among patients who underwent surgery in the FLOT arm was 16.8% compared with 10.0% in the CROSS arm. In both arms, complete regression (18.3% vs 13.3%) or near complete regression (25.1% vs 39.4%) was observed. Most patients across both arms underwent an R0 resection (94.2% vs 95.0%).

Patients in the predefined protocol population in the FLOT (n = 207) and CROSS (n = 196) arms achieved a median OS of 66 months (95% CI, 38-NE) vs 39 months (95% CI, 29-45), respectively (HR, 0.72; 95% CI, 0.54-0.96; P = .023). The 3-year OS rates were 58.1% vs 52.6%, respectively, and the 5-year OS rates were 51.8% vs 40.5%, respectively.

Results from an exploratory subgroup analysis demonstrated that the OS benefit in favor of FLOT vs CROSS was observed in all subgroups examined. The most pronounced benefit was reported in patients aged less than 60 years (HR, 0.57; 95% CI, 0.34-0.95) and those with clinical T-stage T3-4 disease (HR, 0.68; 95% CI, 0.50-0.92).

Most patients in both the FLOT and CROSS arms started neoadjuvant treatment; these patients comprised the predefined protocol population. A majority of patients in both arms completed neoadjuvant treatment (87.3% vs 67.7%) and received neoadjuvant treatment plus surgery (86.0% vs 82.9%). In the FLOT arm, 63.3% of patients received adjuvant treatment and 52.5% completed adjuvant treatment.

In the 90 days post-surgery, 3.2% of patients in the FLOT arm died compared with 5.6% in the CROSS arm. The 30-day postoperative mortality rates were 1.0% vs 1.7%, respectively At the data cutoff, 97 and 121 patients died in these respective arms.^1,2

“Perioperative chemotherapy with FLOT plus surgery improves OS compared with neoadjuvant chemoradiation with CROSS plus surgery in patients with locally advanced, resectable esophageal adenocarcinoma. ESOPEC found that perioperative chemotherapy with FLOT should be preferred over neoadjuvant chemoradiation with the CROSS protocol for improving survival in resectable esophageal adenocarcinoma,” Hoeppner concluded in an oral presentation.

References

1. Hoeppner J, Brunner T, Lordick F, et al. Prospective randomized multicenter phase III trial comparing perioperative chemotherapy (FLOT protocol) to neoadjuvant chemoradiation (CROSS protocol) in patients with adenocarcinoma of the esophagus (ESOPEC trial).J Clin Oncol. 2024;42(suppl 17):LBA1. doi:10.1200/JCO.2024.42.17_suppl.LBA1
2. Chemotherapy before and after surgery may be new standard treatment for some patients with esophageal cancer. News Release. ASCO. June 2, 2024. Accessed June 2, 2024. https://society.asco.org/about-asco/press-center/news-releases/chemotherapy-and-after-surgery-may-be-new-standard-treatment
3. Perioperative chemotherapy compared to neoadjuvant chemoradiation in patients with adenocarcinoma of the esophagus (ESOPEC). ClinicalTrials.gov. Updated May 8, 2024. Accessed June 1, 2024. https://clinicaltrials.gov/study/NCT02509286

Editor's note: The article on the ESOPEC study was published on June 2, 2024, from the press briefing, and was updated on June 4, 2024, with additional information/data from the oral session.