Association of chemotherapy-induced nausea and vomiting or anorexia with plasma levels of five gastrointestinal peptides in patients receiving chemotherapy.

Background: Imbalance between gastrointestinal peptides has been implicated as a cause of chemotherapy-induced nausea and vomiting (CINV) and anorexia in cancer patients. This study comprehensively evaluated the changes in blood levels of five gastrointestinal peptide: substance P, neuropeptide (NPY), motilin, ghrelin and leptin, following chemotherapy, and the relationship between these peptides and CINV or anorexia.

Methods: This single-center, prospective, observational study recruited 20 patients with esophageal cancer, urothelial cancer, or testiculoma undergoing cisplatin-based chemotherapy. Plasma levels of five gastrointestinal peptides were measured on days 1 (baseline; before administering chemotherapy), 3, 5 and 8 of the chemotherapy session. Anorexia and CINV were defined as visual analog scale scores 25 mm or higher at least once during the observation period.

Results: Plasma NPY and leptin were significantly elevated in the early phase (day 3) of the chemotherapy session, while plasma motilin and substance P were significantly elevated in the late phase (days 5 and 8). Plasma motilin showed significant elevation on days 5 and 8 compared to baseline in CINV group but no significant increase in non-CINV group, and the levels were significantly higher in CINV than in non-CINV group. Plasma leptin peaked significantly on day 3 in both anorexia and non-anorexia groups, and remained significantly higher on day 5 compared to baseline in anorexia group but not in non-anorexia group.

Conclusion: CINV is associated with excessive secretion of motilin and anorexia is related to sustained elevation of leptin, suggesting the potential of these peptides as quantitative indicators of CINV and anorexia.