Is there a preferred platinum and fluoropyrimidine regimen for advanced HER2-negative esophagogastric adenocarcinoma? Insights from 1293 patients in AGAMENON-SEOM registry.

BACKGROUND: The optimal chemotherapy backbone for HER2-negative advanced esophagogastric cancer, either in combination with targeted therapies or as a comparator in clinical trials, is uncertain. The subtle yet crucial differences in platinum-based regimens' safety and synergy with combination treatments need consideration. METHODS: We analyzed cases from the AGAMENON-SEOM Spanish registry of HER2-negative advanced esophagogastric adenocarcinoma treated with platinum and fluoropyrimidine from 2008 to 2021. This study focused exclusively on patients receiving one of the four regimens: FOLFOX (5-FU and oxaliplatin), CAPOX (capecitabine and oxaliplatin), CP (capecitabine and cisplatin) and FP (5-FU and cisplatin). The aim was to determine the most effective and tolerable platinum and fluoropyrimidine-based chemotherapy regimen and to identify any prognostic factors. RESULTS: Among 1293 patients, 36% received either FOLFOX (n = 468) or CAPOX (n = 466), 20% CP (n = 252), and 8% FP (n = 107). FOLFOX significantly increased PFS (progression free survival) compared to CP, with a hazard ratio of 0.73 (95% CI 0.58-0.92, p = 0.009). The duration of treatment was similar across all groups. Survival outcomes among regimens were similar, but analysis revealed worse ECOG-PS (Eastern Cooperative Oncology Group-Performance Status), > 2 metastatic sites, bone metastases, hypoalbuminemia, higher NLR (neutrophil-to-lymphocyte ratio), and CP regimen as predictors of poor PFS. Fatigue was common in all treatments, with the highest incidence in FOLFOX (77%), followed by FP (72%), CAPOX (68%), and CP (60%). Other notable toxicities included neuropathy (FOLFOX 69%, CAPOX 62%), neutropenia (FOLFOX 52%, FP 55%), hand-foot syndrome in CP (46%), and thromboembolic events (FP 12%, CP 11%). CONCLUSIONS: FOLFOX shown better PFS than CP. Adverse effects varied: neuropathy was more common with oxaliplatin, while thromboembolism was more frequent with cisplatin.

Efficacy and safety of chemotherapy in young patients with advanced gastroesophageal adenocarcinoma: data from the Spanish AGAMENON-SEOM registry.

BACKGROUND: Gastroesophageal adenocarcinoma in young adults (GCYA) counts for 10-15% of diagnoses. Previous studies have mainly focused on surgical outcomes in patients with resectable tumors; however, systemic therapy for advanced GCYA remains under-evaluated. This study aims to assess the efficacy-related outcomes and safety of first-line chemotherapy (CT) in younger versus older patients with advanced gastroesophageal adenocarcinoma. METHODS: Patients with advanced gastroesophageal adenocarcinoma from the AGAMENON-SEOM registry treated with first-line polychemotherapy between January 2008 and October 2022 were included. We compared clinicopathological features, therapies received, efficacy-related outcomes, and toxicity between individuals aged < and ≥ 45 years. RESULTS: Out of 3386 patients, 263 (7.8%) were < 45 years. Young patients exhibited a higher proportion of females affected, lower ECOG-PS ≥ 2, fewer comorbidities, and more aggressive disease-related features, such as higher proportion of diffuse subtype, signet-ring cells, plastic linitis, grade 3, peritoneal metastases and metastatic disease at diagnosis. They received more triple-agent combinations and underwent more surgeries in metastatic setting. No significant differences were observed between groups in overall response rate (53.1% vs. 52.3% in < and ≥ 45 years, respectively, p = 0.579), progression-free survival (6.1 vs. 6.83 months, p = 0.158) and overall survival (11.07 vs. 10.81 months, p = 0.82), even after adjusting for potential confounding factors. Grade 3-4 adverse events were comparable in both groups, although toxicity leading to treatment discontinuation was more frequent in older patients. CONCLUSIONS: In the AGAMENON-SEOM registry, younger patients with GCYA exhibited more aggressive clinicopathological features, and despite receiving more aggressive treatments, similar efficacy outcomes and toxicity profiles were achieved compared to their older counterparts. In the AGAMENON-SEOM registry, GEAC in < 45 years showed more aggressive clinicopathological features and, although treated with more intense first-line CT regimens, similar efficacy outcomes and toxicity were achieved compared to older patients.

The AGAMENON-SEOM model for prediction of survival in patients with advanced HER2-positive oesophagogastric adenocarcinoma receiving first-line trastuzumab-based therapy.

Background: Trastuzumab and chemotherapy is the standard first-line treatment in human epidermal growth factor receptor 2 (HER2)-positive advanced gastro-oesophageal cancer. The objective was to develop a predictive model for overall survival (OS) and progression-free survival (PFS) in patients treated with trastuzumab. Methods: Patients with HER2-positive advanced gastro-oesophageal adenocarcinoma (AGA) from the Spanish Society of Medical Oncology (SEOM)-AGAMENON registry and treated first line with trastuzumab and chemotherapy between 2008 and 2021 were included. The model was externally validated in an independent series (The Christie NHS Foundation Trust, Manchester, UK). Results: In all, 737 patients were recruited (AGAMENON-SEOM, n = 654; Manchester, n = 83). Median PFS and OS in the training cohort were 7.76 [95% confidence interval (CI), 7.13-8.25] and 14.0 months (95% CI, 13.0-14.9), respectively. Six covariates were significantly associated with OS: neutrophil-to-lymphocyte ratio, Eastern Cooperative Oncology Group performance status, Lauren subtype, HER2 expression, histological grade and tumour burden. The AGAMENON-HER2 model demonstrated adequate calibration and fair discriminatory ability with a c-index for corrected PFS/OS of 0.606 (95% CI, 0.578-0.636) and 0.623 (95% CI, 0.594-0.655), respectively. In the validation cohort, the model is well calibrated, with a c-index of 0.650 and 0.683 for PFS and OS, respectively. Conclusion: The AGAMENON-HER2 prognostic tool stratifies HER2-positive AGA patients receiving trastuzumab and chemotherapy according to their estimated survival endpoints.