BACKGROUND: This study was performed to estimate the genetic effects of HtrA1 polymorphisms rs1049331 and rs11200638 on treatment response in stage III colon cancer patients receiving 5-FU-based chemotherapy.

MATERIAL AND METHODS: A total of 105 stage III colon cancer patients who received postoperative 5-FU based adjuvant chemotherapy were included in our study. Chemotherapy was performed in 3 cycles for the patients. HtrA1 rs1049331 and rs11200638 polymorphisms were genotyped via polymerase chain reaction with sequencing method. The treatment response was estimated according to the RECIST guidelines.

RESULTS: The response rate of the eligible patients was 53.33%. For rs1049331, the presences of TT genotype and T allele indicted reduced chemotherapy sensitivity (adjusted TT: OR=1.736, 95%CI: 1.001-3.011, P=0.049; T: OR=1.801, 95%CI: 1.054-2.932, P=0.039). The rs11200638 polymorphism had no significant association with chemotherapy sensitivity in the study population (P>0.05 for all).

CONCLUSIONS: HtrA1 rs1049331 polymorphism, but not rs11200638 polymorphism, can influence individual sensitivity to 5-FU-based treatment in stage III colon cancer patients.

Keywords: disease resistance, Heat-Shock Proteins, Polymorphism, Genetic, Sigmoid Neoplasms, Antimetabolites, Antineoplastic, Asians, Case-Control Studies, Chemotherapy, Adjuvant, Colectomy, Colon, Colonic Neoplasms, Fluorouracil, High-Temperature Requirement A Serine Peptidase 1, Polymorphism, Single Nucleotide, Response Evaluation Criteria in Solid Tumors