Table I.

Search strategy on PubMed

Search	Query
#1	“Colorectal Neoplasms”[Mesh]
#2	(((((((((((((((Colorectal Neoplasm) OR (Neoplasm, Colorectal)) OR (Colorectal Neoplasm)) OR (Neoplasms, Colorectal)) OR (Colorectal Tumors)) OR (Colorectal Tumor)) OR (Tumor, Colorectal)) OR (Tumors, Colorectal)) OR (Colorectal Cancer)) OR (Cancer, Colorectal)) OR (Cancers, Colorectal)) OR (Colorectal Cancers)) OR (Colorectal Carcinoma)) OR (Carcinoma, Colorectal)) OR (Carcinomas, Colorectal)) OR (Colorectal Carcinomas)
#3	#1 OR #2
#4	“Chemoprevention”[Mesh]
#5	(((((Chemoprophylaxis) OR (Precaution))OR (Precautions, Universal)OR (Precaution, Universal)OR (Universal Precaution)
#6	#4 OR #5
#7	(Cohort studies) OR (Randomized controlled trials)[Publication Type]
#8	#3 AND #6 AND #7