“…An association between the ABO blood group system and colorectal cancer risk has not been confirmed in series of studies performed in different populations and ethnicities (Halvorsen, 1986;Slater et al, 1993;Khalili et al, 2011). Similarly, a lack of statistically significant correlations was observed between the ABO system and development of prostate cancer (Wajsman et al, 1997), benign prostate hyperplasia (Beasley, 1964), bladder cancer (Orihuela and Shahon, 1987;Raitanen and Tammela, 1993), testicular cancer (Morrison, 1976;O'Connell and Christenson, 1980) and salivary gland cancer (Pinkston and Cole, 1996). Additionally, several studies reported contradictory results.…”