Immunonutrition for patients undergoing surgery for head and neck cancer.

Systematic review and meta-analysis of randomized trials in adults undergoing elective surgery for head and neck cancer, including cancers of the oral cavity, pharynx, and larynx. Active intervention arms across trials received perioperative immunonutrition formulas, usually compared with standard feeding.

Immunonutrition was given as perioperative enteral or oral feeding formulas enriched mainly with arginine, omega-3 fatty acids, and often RNA/nucleotides; some trials also used glutamine-containing products. Regimens varied across studies, commonly delivered preoperatively and postoperatively or postoperatively alone, compared with standard feeding or arginine-free enteral nutrition.

Immunonutrition may reduce fistula formation by about half, but there is no clear evidence that it reduces length of hospital stay, wound infections, or mortality. Tolerance and adverse events appeared similar between immunonutrition and standard feeding. Benefits did not consistently differ between preoperative plus postoperative regimens and postoperative-only regimens. Overall evidence quality was low to very low, so the clinical effect remains uncertain despite a possible benefit for fistula prevention.

The evidence base was small, heterogeneous, and inconsistently reported, with low to very low certainty overall. Trial regimens, timing, and formulas varied substantially, and applicability to malnourished patients remains uncertain. Larger, high-quality trials are needed to confirm benefit and clarify effects on other postoperative outcomes.