| Objective: Ovarian cancer is the highest mortality rate of gynecologic malignant tumor, the most common histological type is epithelial ovarian cancer(EOC). The principle of treatment is comprehensive treatment, which consists of surgery and chemotherapy or radiotherapy. Because of the lake of typical clinical manifestations, and there is on effective molecular marker, 70% patients are detected in late stages. In the primary treatment only 70% of the patients undergoing chemotherapy are sensitive to platinum[1]. After surgery and chemotherapy, two-thirds recur in 3 years, so the prognosis of ovarian cancer is poor, and the 5-year survival rate is 20%~40%[2]. Searching for new screening molecular marker and therapeutic strategies for EOC has become the focus of the present study. At present a lot of evidence show that ovarian cancer has immunogenicity [3], immune therapy for ovarian cancer received wide attention. PD-1(programmed death 1) is an important immunosuppressive factor, inhibits the activity of T cells with its primary ligand PD-L1[4]. So far there are many studies about the relationship between PD-1 and carcinoma. In this study we investigated the association between polymorphisms of PD-1 and the risk of EOC and its clinical prognosis from the North of China.Methods: 1) Specimen collection: This study consisted of 620 surgically confirmed EOC cases and 620 healthy women. 5ml venous blood was drawn from each subject into vacutainer tubes containing EDTA and stored at 4? refrigeratory. Then recorded the medical history and family information of the volunteers. After sampling, the members extracted the genomic DNA within one week using proteinase-K digestion followed by a salting out procedure. The rs36084323 and rs2227981 polymorphism were genotyped by polymerase chain reaction- ligase detection reaction(PCR-LDR) analysis. 2)Study on the association of two SNPs in PD-1 with the risk of EOC(case-control): 620 EOC patients act as cases and 620 healthy women act as controls. Then analyze the statistical difference of genotype and alleletype frequencies of the PD-1.1?PD-1.5in cases and controls. 3) Study on the association of two SNPs in PD-1 with the prognosis of EOC patients(cohort study): we have 3-year follow-data of 258 patients and 5-year follow data of 163 patients in 620 cases, which contains Progression-Free Survival(PFS), Overall Survival(OS). 4) Statistic methods: SPSS 22.0 software package was used for statistical analysis. Hardy–Weinberg analysis was performed by comparing the expected and observed genotype frequencies. The genotype and alleletype distribution in patients and healthy controls was compared using the Chi-square test. The odds ratio(OR) and 95% confidence interval(CI) were calculated using an unconditional logistic regression model. The haplotype frequencies of PD-1.1 and PD-1.5 in patients and healthy controls were compared using the haplotype analysis. Kaplan-Meier curves were constructed in order to investigate survival difference between the wild-type and variant genotypes. The wild-type alleles as reference, differences were tested for statistical significance using the log-rank test. HRs and 95% CIs were calculated using multivariate Cox proportional hazard models to adjust for appropriate variables, such as age,stage,grade,histology status and tumor residual size. All statistical tests were two-sided, and P-values<0.05 were considered statistically significant.Results: 1 The genotype frequencies of the PD-1.1(rs36084323)A/A,A/G,G/G in EOC patients and healthy controls were respectively 27.3%,48.6%,24.2% and 20.8%,52.1%,27.1%. There was significant difference in genotype of the rs36084323 between cases and controls(P=0.028). Compared with A/A genotype, patients with A/G genotype and G/G genotype significantly decreased the risk of epithelial ovarian cancer. The odds ratio was respectively 0.71(95%CI=0.54-0.94) and 0.68(95%CI=0.50-0.94). In patients and controls, the A and G allele frequency distribution were 51.3%, 48.7% and 46.9%, 53.2%,significant difference was found in allele distributions of the PD-1.1 between above two(P=0.02). Compared with A allele, patients with G allele significantly decreased the risk of epithelial ovarian cancer. The odds ratio was 0.83(95%CI=0.71-0.97); 2 The genotype frequencies of the PD-1.5(rs2227981)C/C,C/T, T/T in EOC patients and healthy controls were respectively 56.6%,37.6%,5.8%and 51.5%,40.3%,8.2%. There was no significant difference in genotype of the rs2227981 between cases and controls(P=0.096). In patients and controls, the C/C genotype and C/T+T/T genotype frequency distribution were 56.6%, 43.4% and 51.5%, 48.5%,no significant difference was found in comparing this two frequencies(P=0.064). In patients and controls, the C and T allele frequency distribution were 75.4%, 24.6% and 71.6%, 28.4%,significant difference was found in allele distributions of the PD-1.5 between above two(P=0.033). Compared with C allele, patients with T allele significantly decreased the risk of EOC. The odds ratio was 0.82(95%CI=0.69-0.98); 3 The heplotype frequencies of the PD-1.1 and PD-1.5 AC?AT?GC?GT were respectively 51.2%,0.3%,24.2%,24.3% in cases and 46%,0.9%,25.6%,27.5% in controls. Significant difference was found in these two groups(P=0.023), compared with AC haplotype, patients with GT haplotype decreased the risk of EOC. The odds ratio was 0.79(95%CI=0.65-0.96); 4 The 3-year progression-free survival(PFS) of the PD-1.1genotype A/A?A/G?G/G in EOC patients were respectively 12?22?13 months, while the overall survival(OS) were respectively 29?36?36 months, 5-year PFS were respectively 13?12?12 months, 5-year OS were respectively 38?33?52 months. Kaplan-Meier estimates demonstrated that no significant difference was found between the genotypes and 3-year?5-year PFS and OS of the EOC cases. No associations between the PD-1.1(rs36084323) A/A,A/G,G/G polymorphism and the clinical prognosis of patients with EOC was found; 5 The 3-year PFS of the PD-1.5genotype C/C?C/T+T/T in EOC patients were respectively 15?16 months, while the OS were respectively 36?36 months, 5-year PFS were respectively12?12 months, 5-year OS were respectively 36?44months. Kaplan-Meier estimates demonstrated that no significant difference was found between the genotypes and PFS?OS of EOC cases. Kaplan-Meier estimates demonstrated that no significant difference was found between the genotypes and 3-year?5-year PFS and OS of the EOC cases. No associations between the PD-1.5(rs2227981) C/C,C/T and T/T polymorphism and the clinical prognosis of patients with EOC was found.Conclusions:1 The results indicated that the PD-1.1(rs36084323) polymorphism may correlate with the risk of EOC in women from the North of China. Women with G allele may decrease the risk of EOC.2 The C allele of PD-1.5(rs2227981) polymorphism may be related to the pathogenesis of EOC.3 The haplotype of PD-1.1 and PD-1.5 may correlate with the risk of EOC.4 There are no association between the PD-1.1(rs36084323) ?PD-1.5(rs2227981) polymorphism and the clinical prognosis of patients with EOC. |
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