More effective prognostic indicators are required for managing malignancy in older adults. Previous research has connected N-terminal pro-B-type Natriuretic Peptide (NT-proBNP) with sarcopenia, a condition linked to decreased cancer survival, yet data on baseline NT-proBNP as a marker of cancer outcome are scarce. The GO2 clinical trial involved elderly or frail patients in the United Kingdom (UK) with advanced gastroesophageal tumors and explored reduced-dose chemotherapy. Using data from this study, we examined whether NT-proBNP could predict outcomes and whether its effect was influenced by frailty. This work represents a secondary analysis of an already completed clinical study. Frailty was determined through Eastern Cooperative Oncology Group (ECOG) performance status (PS) and the GO2 frailty index, which encompassed nine geriatric areas. A corrected NT-proBNP (cBNP) value was obtained for each participant, standardized to the local laboratory upper limit of normal (ULN). A total of 241 participants were assessed. Median age was 76 years (range 52–89); 187 (77.6%) were men, and 211 (87.6%) had adenocarcinoma. At study entry, 80 (33.2%) had NT-proBNP above the ULN. No significant link was found between cBNP and ECOG PS (p = 0.36) or the GO2 frailty classification (p = 0.58). Individuals in the highest cBNP group (n = 59) showed poorer median overall survival of 5.3 months, compared with 6.8 months for the medium group (n = 120) and 8.2 months for the lowest group (n = 61); HR 1.57 (95% CI, 1.04–2.37), p = 0.031. This remained significant in multivariate Cox regression (HR 1.69, p = 0.01) after adjusting for GO2 stratification parameters. No substantial interaction between NT-proBNP and frailty was detected. Baseline NT-proBNP appeared to independently predict outcome in older patients with advanced gastroesophageal cancer. Further prospective validation is needed to confirm these findings and to explore whether cardioprotective management may benefit individuals identified with elevated NT-proBNP levels.
