Therefore, incidence of grade ≥2 diarrhea possibly includes cases caused partially by enterohepatic circulation of APC and NPC, but genotype of rs9351963 in KCNQ5 correlates with the start date of treatment with antidiarrheal agents (Spearman's rank correlation coefficient ρ = −0.198, p = 0.00995). This evidence concerns the gene APC and nasopharyngeal carcinoma.