High SLFN11 expression predicts better survival for patients with KRAS exon 2 wild type colorectal cancer after treated with adjuvant oxaliplatin-based treatment

BACKGROUND: SLFN11 was reported to be a predictive marker for DNA damage drugs. The study was to investigate whether SLFN11 expression is related to sensitivity to adjuvant oxaliplatin-based treatment in colorectal cancer. METHODS: A tissue microarray, made with specimens from consecutive 261 patients who received oxaliplatin based adjuvant chemotherapy, was stained with anti-SLFN11 antibody. The staining was dichotomized as high or low expression. SLFN11 expression was correlated to clinicopathological factors, KRAS exon 2 mutation and survival. RESULTS: SLFN11 high expression was found in 16.9 % of patients, and KRAS exon 2 mutation was detected in 32.2 % of patients. SLFN11 was expressed more common in well/moderate differentiation tumors(comparing to poor differentiation ones, 21 % v 4.9 %, P = 0.003) and stage II tumors(comparing to stage III tumors, 26.1 % v 11.4 %,p = 0.006). 23 out of 153 patients with KRAS exon 2 wild-type CRC had SLFN11 high expression, no death events was recorded in the 23 patients until last follow up. These patients had significantly better overall survival (OS) than those with SLFN11 low expression tumors (100 % vs 78.2 %, log rank P = 0.048). However, among patients with KRAS exon 2 mutant tumors, OS did not significantly differ between those with SLFN11 high and SLFN11 low tumors (Log rank P = 0.709). CONCLUSIONS: SLFN11 expression predicts good better survival in colorectal cancer patients with KRAS exon 2 wild type who have received oxaliplatin based adjuvant chemotherapy.