l-Menthol for Color Difference Change Between Early Gastric Cancer and Surrounding Mucosa: A Prospective Study

l-Menthol sprayed on early gastric cancer (EGC) has been reported to improve the visibility of the lesion. However, its impact when used in combination with novel image-enhanced endoscopy has not been investigated.

This study aimed to evaluate the visual effect of spraying l-menthol on EGC under linked color imaging (LCI).

This open-label, single-arm, prospective study investigated the color difference between EGC and the surrounding mucosa (ΔE_G) before and after spraying l-menthol. The primary endpoint was the percentage of lesions with ΔE_G ≥ 5 on LCI. The percentage of lesions with ΔE_G  ≥ 5 on white light imaging (WLI) and blue laser imaging (BLI), ΔE_G before and after spraying l-menthol, and percentage of lesions with increased ΔE_G after spraying l-menthol constituted the secondary endpoints.

Sixty patients were included in the final analysis. 100% lesions had ΔE_G ≥ 5, both before and after spraying l-menthol on LCI, with similar results observed in WLI as well as BLI. The median ΔE_G on LCI, WLI, and BLI increased after spraying l-menthol (LCI: 16.9 vs. 21.5, p < 0.01; WLI: 10.4 vs. 13.4, p < 0.01; BLI; 12.1 vs. 15.7, before and after, respectively, p < 0.01); and LCI demonstrated the highest percentage of lesions with increased ΔE_G (LCI, WLI, and BLI: 98.3%, 81.7%, and 76.7%, respectively, p < 0.01).

Although spraying l-menthol did not improve the visibility of EGC under LCI observation, a significant increase in ΔE_G was observed in LCI (jRCTs 021200027).