Few protective effects of the SET8 rs16917496 T/C polymorphism against cancer development were found in the PCR-sequencing subgroup (CC vs. TT: OR = 0.61, 95%CI = 0.44–0.86, P = 0.01, I2 = 18.6%; CC vs. TT+TC: OR = 0.59, 95%CI = 0.37–0.94, P = 0.03, I2 = 41.0%) and ovarian cancer subgroup (CC vs. TT: OR = 0.59, 95%CI = 0.37–0.94, P = 0.03, I2 = 0%; CC vs. TT+TC: OR = 0.52, 95%CI = 0.33–0.82, P = 0.01, I2 = 0%). This evidence concerns the gene KMT5A and ovarian carcinoma.