Timing matters: gastrostomy placement and outcomes in patients with head and neck cancer undergoing chemoradiotherapy.

Background: Patients with head and neck cancer (HNC) undergoing chemoradiotherapy (CRT) are at high risk of malnutrition. The optimal timing of gastrostomy [percutaneous endoscopic gastrostomy (PEG) or radiologically inserted gastrostomy (RIG)] placement remains controversial. Objective: To compare survival, nutritional outcomes, and gastrostomy-related complications between prophylactic and later gastrostomy placement. Methods: In this retrospective TriNetX US Collaborative Network cohort, prophylactic gastrostomy (within ±14 days of CRT initiation) was compared with early-reactive (15-90 days), late-reactive (91-180 days), and very-late (>180 days) placement using 1:1 propensity-score matching on demographic, clinical, and laboratory characteristics. Survival was measured from index gastrostomy; therefore, comparisons with later placement were conditional on survival until gastrostomy and considered exploratory rather than estimates of the effect of placement timing. Results: The prophylactic-versus-very-late comparison included 2,251 matched pairs, analyzed at 1-2 and 2-5 years. Post-gastrostomy survival was similar between prophylactic and early-reactive placement at both intervals [hazard ratio (HR) 0.94 and 0.95; both nonsignificant]. Compared with very-late placement, survival did not differ at 1-2 years (HR 0.90, 95% CI 0.65-1.25) but was higher at 2-5 years (88.4% vs. 83.2%; HR 0.69, 95% CI 0.48-0.98); adjusted HRs were 0.72 (0.54-0.96) and 0.61 (0.45-0.83), respectively. Survival was higher with prophylactic versus late-reactive placement at 1-2 years (84.2% vs. 77.8%; HR 0.70, 95% CI 0.54-0.90), but not at 2-5 years (HR 0.64, 95% CI 0.32-1.26). Prophylactic placement was associated with fewer gastrostomy-related complications than very-late placement (1.8% vs. 3.1% at 1-2 years; 1.3% vs. 2.6% at 2-5 years), less aspiration pneumonia at 1-2 years (1.0% vs. 1.9%), and higher serum albumin (3.89 vs. 3.70 g/dL; all Conclusion: Prophylactic and early-reactive placement had comparable post-gastrostomy survival, supporting early-reactive placement as a reasonable alternative in appropriately monitored patients. Poorer outcomes with late and very-late placement may identify a clinically higher-risk population rather than demonstrate a benefit of earlier placement. Prospective target-trial emulation studies are needed to define optimal timing.