We also coded

I of TNM stage as 0, II as 1 and III as 2. As shown in Table 2, the 16278 and 16399 alleles were identified as independent predictors for ESCC outcome. Selleck XAV939 The length of survival for patients with the rare allele 16278T genotype was significantly shorter than that for patients with the frequent allele 16278C (relative risk, 3.001; 95% CI, 1.029 – 8.756; p = 0.044) at the 16278 site. The same was seen for the rare allele 16399G genotype when compared with matched alleles 16399A at the 16399 site in ESCC patients (relative risk, 3.483; 95% CI, 1.068 – 11.359; p = 0.039) (Table 2). These data demonstrated the strong prediction power of 16278C/T and 16399A/G on outcome for ESCC patients. Figure 1 Survival curve according to the nucleotide at position (A)

16274, (B) 16278 and (C) 16399 in D-loop of ESCC patients. Table 2 Multivariate analysis of prognostic factors associated with post-operational survival in ESCC patients with Cox proportional hazards model Factors Relative risk 95% C.I. p see more value Stage of tumor 1.328 0.955-1.848 0.092 16274(G/A) 0 0 0.975 16278(C/T) 3.001 1.029-8.756 0.044 16399((A/G) 3.483 1.068-11.359 0.039 Discussion Selected SNPs in the D-loop region have been examined for the ability to predict cancer risk in other types of tumour [11–14]. The present study has extended those much analyses to determine the cancer risk and the post-operational survival-associated germline SNPs in a continuous sequence of mtDNA between nucleotides 16190 and 583 in ESCC

patients. Three SNPs, 16274G/A, 16278C/T and 16399A/G, were identified for their association with post-operational survival at statistically significant levels by the log-rank test. Multivariate survival analysis identified 16278C/T and 16399A/G to be independent prediction markers for ESCC outcome. We suggest for the first time that SNPs in the D-loop is a prognostic factor in ESCC patients. The relative risk (RR) of death in patients was significantly higher (16278C versus 16278T, RR, 3.001; 95% CI, 1.029 – 8.756; p = 0.044. 16399A versus 16399G, RR, 3.483; 95% CI, 1.068 – 11.359; p = 0.039). Nucleotides 16278 and 16399 are located in hypervariable segment 1 (HV1), which is associated with high rates of mutation [16], but the functional significance of these SNPs in HV1 is not known. Minor alleles of 16278T and 16399G are associated with dramatically shorter period of postoperative survival; the survival curve decreased rapidly in patients carrying these alleles (Figure 1). We compared the distribution frequency of these two SNPs between ESCC patients and normal controls; among 60 age-matched controls, only one carried the 16278T allele and none carried the 16399G allele.