Shaogui Wan

Genetic Polymorphisms in Pre-microRNA Genes as Prognostic Markers of Colorectal Cancer

Background: Cumulative data have shown that microRNAs (miRNA) are involved in the etiology and prognosis of colorectal cancer (CRC). Genetic polymorphisms in pre-miRNA genes may influence the biogenesis and functions of their host miRNAs. However, whether these polymorphisms are associated with CRC prognosis remains unknown. Methods: We analyzed the effects of seven single-nucleotide polymorphisms (SNP) in pre-miRNA genes on the prognosis of a Chinese population with 408 CRC patients with surgically-resected adenocarcinoma. Results: Two SNPs were identified to be significantly associated with recurrence-free survival and overall survival of the patients. The most significant SNP was rs6505162 in pre-miR-423. Compared with the homozygous wild-type genotype, the variant-containing genotypes of this SNP were significantly associated with both the overall survival (HR = 2.12, 95% CI = 1.34–3.34, P = 0.001) and the recurrence-free survival (HR = 1.59, 95% CI = 1.08–2.36, P = 0.019). Another SNP, rs4919510 in pre-miR-608, was also associated with altered recurrence-free survival (HR = 0.61, 95% CI = 0.41–0.92, P = 0.017). These effects were evident only in patients receiving chemotherapy but not in those without chemotherapy. In addition, the combined analysis of the two SNPs conferred a 2.84-fold (95% CI = 1.50–5.37, P = 0.001) increased risk of recurrence and/or death. Similarly, this effect was only prominent in those receiving chemotherapy (P < 0.001) but not in those without chemotherapy (P = 0.999). Conclusions: Our data suggest that genetic polymorphisms in pre-miRNA genes may impact CRC prognosis especially in patients receiving chemotherapy, a finding that warrants further independent validation. Impact: This is one of the first studies showing a prognostic role of pre-miRNA gene SNPs in CRC. Cancer Epidemiol Biomarkers Prev; 21(1); 217–27. ©2011 AACR.

Comprehensive analysis of common serum liver enzymes as prospective predictors of hepatocellular carcinoma in HBV patients.

Background Serum liver enzymes are frequently tested in clinics to aid disease diagnosis. Large observational studies indicated that these enzymes might predict cancer risk and mortality. However, no prospective study has reported on their relationships with the risk of HBV-related hepatocellular carcinoma (HCC). Methodology/Principal Findings We evaluated the predictive values of four routinely tested liver enzymes (alanine aminotransferase [ALT], aspartate aminotransferase [AST], alkaline phosphatase [ALP], and gamma-glutamyltransferase [GGT]) in HCC risk in a prospectively enrolled clinical cohort of 588 Korean American HBV patients. For all four enzymes, the baseline level as well as the average and maximum levels during the first 1 or 2 years of follow-up were analyzed using multivariate Cox proportional hazards model. Patients were categorized into a normal or an elevated group based on the clinical cut-off of each enzyme. During a median follow-up of 7.5 years, 52 patients (incidence rate, 8.8%) developed HCC. The incidence rates were higher in the elevated groups for all four enzymes. The most significant finding was for GGT, with the highest incidence rate of 16.4% in the elevated group compared to 4.6% in the normal group (P<0.001). Compared to patients with normal baseline GGT, those with elevated GGT exhibited a significantly increased HCC risk with a hazards ratio (HR) of 2.60 (95% confidence interval [CI], 1.41–4.77, P = 0.002). Further analyses revealed a cumulative effect between baseline GGT and ALP (HR = 3.41, 95% CI 1.54–7.56, P = 0.003). Conclusions Significance Serum GGT might predict HCC risk in HBV patients individually or jointly with other enzymes.

Relative telomere length: a novel non-invasive biomarker for the risk of non-cirrhotic hepatocellular carcinoma in patients with chronic hepatitis B infection

BACKGROUND AND AIMS Telomere length has emerged as a promising risk predictor of various cancers including hepatocellular carcinoma (HCC). However, the majority of studies in this area measured telomere length in hepatocytes and one in lymphocytes with conflicting results. Moreover, no studies have been reported on using circulating DNA telomere length as a non-invasive HCC biomarker. METHODS We conducted a nested case-control study to determine the relative telomere length (RTL) in serum DNA from 140 hepatitis B virus (HBV)-related HCC cases and 280 frequency-matched cancer-free HBV controls. RESULTS Cases had a significantly longer RTL (median, 0.31; range, 0.02-2.31) than controls (median, 0.20; range, 0.01-1.60) (P = 0.003). Consistently, longer RTLs conferred a significantly increased HCC risk compared to short RTLs in a univariate logistic regression analysis (odds ratio [OR] = 1.55, 95% confidence interval [CI] = 1.02-2.33, P = 0.038). This association attenuated after multivariate adjustment (OR = 1.40, 95% CI = 0.90-2.19, P = 0.132). In a quartile analysis, a significant dose-response relationship was noted in univariate analysis (P(trend) = 0.017) which was again attenuated in multivariate analysis (P(trend) = 0.079). Further analyses revealed that the significant association between serum RTL and HCC risk was evident in non-cirrhotic (OR = 3.54, 95% CI 1.58-7.93 P = 0.002), but not cirrhotic (OR = 0.95, 95% CI 0.55-1.64, P = 0.860) HBV patients. Moreover, the significantly increased HCC risk conferred by cirrhosis was modulated by RTL with a significant interaction effect (P(interaction) = 0.013). CONCLUSIONS RTL in circulating cell-free serum DNA could potentially be used as a novel non-invasive biomarker for non-cirrhotic HCC. Prospective cohort studies are warranted to validate this finding and assess its clinical significance in HCC prevention.

GWAS-identified colorectal cancer susceptibility locus associates with disease prognosis

PURPOSE Extensive evidence has suggested that risk factors of cancer development may also modulate cancer clinical outcome. Recent genome-wide association (GWA) studies identified several single nucleotide polymorphisms (SNPs) predisposing to colorectal cancer (CRC). Given the pivotal importance of these variants in CRC, we sought to evaluate their associations with clinical outcomes of the disease. EXPERIMENTAL DESIGN In a well-characterised cohort including 380 Chinese CRC patients, we genotyped seven SNPs identified in previous multi-stage GWA studies and analysed their associations with patient recurrence and survival. RESULTS One SNP on chromosome 15q13, rs4779584 was associated with reduced risk of death with a hazard ratio (HR) of 0.33 (95% confidence interval [CI] 0.15-0.72, P = 0.007). Another SNP in a gene-desert region on chromosome 10p14, rs10795668, was associated with a reduced risk of recurrence with an HR of 0.55 (95% CI 0.30-1.00, P = 0.05). In a stratified analysis, this association was only evident in patients receiving chemotherapy (HR = 0.32, 95% CI 0.14-0.78, P = 0.01, log rank P = 0.004), but not in those without chemotherapy (HR = 1.08, 95% CI 0.43-2.73, P = 0.87, log rank P = 0.66). Moreover, we found that the effects of chemotherapy on CRC recurrence was only evident in patients with the variant-containing genotypes (HR = 0.35, 95% CI 0.13-0.94, P = 0.04) but not in those with the wild-type genotype of rs10795668. Further analyses indicated a borderline significant interaction effect (P interaction = 0.05) between rs10795668 and chemotherapy on patient recurrence. CONCLUSIONS Our data suggested that rs10795668, a CRC susceptibility variant identified by GWA studies, might be used as a biomarker to identify CRC patients with high risk of recurrence after chemotherapy.

Short leukocyte telomere length predicts poor prognosis and indicates altered immune functions in colorectal cancer patients

BACKGROUND Numerous studies indicate that the leukocyte telomere length is associated with the risk of cancers, including colorectal cancer (CRC). However, the prognostic value of leukocyte telomere length in CRC patients has not been investigated. PATIENTS AND METHODS Relative telomere length (RTL) of peripheral blood leukocytes (PBLs) from 571 CRC patients receiving surgical resection was measured using a polymerase chain reaction-based method. The Cox proportional hazards ratio model and the Kaplan-Meier curve were used to estimate the association between RTL and the clinical outcome of CRC patients in the training set (90 patients) and the testing set (86 patients). Finally, an independent cohort of 395 patients was used as an external validation set. The immunophenotype of PBLs and the plasma concentration of several immune-related cytokines were determined by flow cytometry and enzyme-linked immunosorbent assay, respectively. RESULTS Patients with shorter RTL had significantly poorer overall survival and relapse-free survival than those with longer RTL in the training, testing and validation sets. Furthermore, leukocyte RTL and Tumor-Node-Metastasis (TNM) stage exhibited a significant joint effect in the prognosis prediction of combined CRC patients, indicating that patients with both short RTL and advanced stages had the worst prognosis, when compared with other subgroups. In addition, patients with short RTL showed the higher percentage of CD4+ T cell and the lower percentage of B cell in peripheral blood mononuclear cells, as well as the lower concentration of plasma transforming growth factor-β1, suggesting a possibility that the immune functions changed with RTL alteration. CONCLUSIONS Our study for the first time demonstrates that leukocyte RTL is an independent prognostic marker complementing TNM stage and associated with the immune functions in CRC patients.BACKGROUND Numerous studies indicate that the leukocyte telomere length is associated with the risk of cancers, including colorectal cancer (CRC). However, the prognostic value of leukocyte telomere length in CRC patients has not been investigated. PATIENTS AND METHODS Relative telomere length (RTL) of peripheral blood leukocytes (PBLs) from 571 CRC patients receiving surgical resection was measured using a polymerase chain reaction-based method. The Cox proportional hazards ratio model and the Kaplan-Meier curve were used to estimate the association between RTL and the clinical outcome of CRC patients in the training set (90 patients) and the testing set (86 patients). Finally, an independent cohort of 395 patients was used as an external validation set. The immunophenotype of PBLs and the plasma concentration of several immune-related cytokines were determined by flow cytometry and enzyme-linked immunosorbent assay, respectively. RESULTS Patients with shorter RTL had significantly poorer overall survival and relapse-free survival than those with longer RTL in the training, testing and validation sets. Furthermore, leukocyte RTL and Tumor-Node-Metastasis (TNM) stage exhibited a significant joint effect in the prognosis prediction of combined CRC patients, indicating that patients with both short RTL and advanced stages had the worst prognosis, when compared with other subgroups. In addition, patients with short RTL showed the higher percentage of CD4(+) T cell and the lower percentage of B cell in peripheral blood mononuclear cells, as well as the lower concentration of plasma transforming growth factor-β1, suggesting a possibility that the immune functions changed with RTL alteration. CONCLUSIONS Our study for the first time demonstrates that leukocyte RTL is an independent prognostic marker complementing TNM stage and associated with the immune functions in CRC patients.

Potentially functional genetic variants in KDR gene as prognostic markers in patients with resected colorectal cancer.

Angiogenesis plays a key role in the development and treatment response of various tumors. The signaling transductions mediated by the binding of vascular endothelial growth factor (VEGF) to its receptor KDR (kinase insert domain receptor) is the most important pathway in tumor angiogenesis. Single nucleotide polymorphisms (SNPs) in VEGF have been extensively implicated in the etiology and treatment outcome of colorectal cancer (CRC). However, no study has been reported evaluating the role of KDR SNPs in CRC prognosis. We herein assessed the association between four potentially functional KDR SNPs and tumor recurrence in a Chinese population with 408 surgically resected CRC patients. The most significant SNP was for rs10013228 located in the KDR gene promoter. Compared with the homozygous wild‐type genotype, the variant‐containing genotypes of this SNP were significantly associated with a reduced recurrence risk with a hazard ratio (HR) of 0.53 (95% confidence interval [CI] 0.30–0.95, P = 0.032). Moreover, a borderline significant association was noted for another promoter SNP, rs2071559, with an HR of 0.67 (95% CI 0.42–1.07, P = 0.092). In stratified analysis, the associations of both SNPs were more prominent in patients receiving chemotherapy (HR = 0.47, 95% CI 0.23–0.94, P = 0.033 for rs10013228 and HR = 0.55, 95% CI 0.32–0.95, P = 0.032 for rs2071559). Further analysis revealed a protective effect on patient recurrence by chemotherapy (HR = 0.56, 95% CI 0.32–1.01, P = 0.046), which was more evident in patients with the variant‐containing genotypes of each of the two SNPs (HR = 0.09, 95% CI 0.02–0.55, P = 0.009 for rs10013228 and HR = 0.39, 95% CI 0.18–0.86, P = 0.020 for rs2071559). Collectively, our findings suggest SNPs in the KDR gene modulate CRC recurrence, especially in those receiving chemotherapy. (Cancer Sci 2012; 103: 561–568)

Association between leukocyte telomere length and glioma risk: a case-control study

BACKGROUND Compelling epidemiological evidence indicates that alterations of telomere length are associated with risks of many malignancies in a tumor-specific manner, such as lung cancer, breast cancer, and non-Hodgkins lymphoma. However, the association between leukocyte telomere length and glioma risk has not been investigated. METHODS Relative telomere length (RTL) of peripheral blood leukocytes from 467 glioma patients and 467 healthy controls, matched by age and sex, was measured using the real-time PCR-based method in a case-control study. An unconditional multivariate logistic regression model was applied to estimate the association between RTL and glioma risk. RESULTS Glioma patients showed notably longer RTL than controls (median, 0.555 vs 0.444; P > .04). RTL was negatively correlated with age in both cases (ρ = -0.430; P < .001) and controls (ρ = -0.388; P < .001). After adjusting for age, sex, smoking status and family history of cancer, multivariate logistic regression analysis showed that there was a U-shaped association between RTL and glioma risk (P for nonlinearity <.001). Compared with individuals in the second tertile of RTL, the odds ratios (95% CI) for participants in the first and third tertiles were 2.16 (range, 1.52-3.09) and 3.51 (range, 2.45-5.00), respectively. Stratified analysis showed that the association between RTL and glioma risk was not modulated by major host characteristics. CONCLUSIONS Our study demonstrates for the first time that either shorter or longer RTL in peripheral blood leukocytes is associated with increased glioma risk, which warrants further investigation in the future.

Telomere length in circulating serum DNA as a novel non-invasive biomarker for cirrhosis: a nested case-control analysis.

Previous studies have indicated that telomere length is associated with altered risk of various tumours including hepatitis B virus (HBV)‐related hepatocellular carcinoma. However, the association between telomere length and the risk of cirrhosis has not been reported.

Post-diagnosis hemoglobin change associates with overall survival of multiple malignancies – results from a 14-year hospital-based cohort of lung, breast, colorectal, and liver cancers

BackgroundAnemia refers to low hemoglobin (Hb) level and is a risk factor of cancer patient survival. The National Comprehensive Cancer Network recently suggested that post-diagnosis Hb change, regardless of baseline Hb level, indicates the potential presence of anemia. However, there is no epidemiological study evaluating whether Hb change has direct prognostic values for cancer patients at the population level.MethodsWe identified 6675 patients with a diagnosis of primary lung, breast, colorectal, or liver cancer who visited the Kimmel Cancer Center at the Thomas Jefferson University from 1998 to 2011. All patients had at least two Hb measurements within the first six months after diagnosis. We analyzed the main, dose-dependent, and time-dependent effects of Hb changes on patient survival.ResultsCompared to patients with a low Hb change (|∆Hb|≤2.6), those having a |∆Hb|>2.6 exhibited a significantly shorter survival (hazard ratio=1.40, 95% confidence interval 1.31-1.50, P=4.5 × 10-22, Plog rank=1.6 × 10-39). This association remained significant across the four cancer types. Bootstrap resampling validated these findings 100% of the time with P<0.01 in all patients and in patients of individual cancers. The association exhibited an apparent U-shape dose-dependent pattern. Time-dependent modeling demonstrated that the effect of Hb change on the survival of the overall patient population persisted for approximately 4.5 years after diagnosis.ConclusionPost-diagnosis Hb change associates with the survival of multiple cancers and may have clinical values in tailoring anti-anemia treatments. Because Hb level is frequently measured during cancer treatment, Hb changes may be a potentially important variable in building cancer prognosis models.

Cell-free circulating mitochondrial DNA content and risk of hepatocellular carcinoma in patients with chronic HBV infection.

Recent studies have demonstrated a potential link between circulating cell-free mitochondrial DNA (mtDNA) content and cancers. However, there is no study evaluating the association between circulating mtDNA as a non-invasive marker of hepatocellular carcinoma (HCC) risk. We conducted a nested case-control study to determine circulating mtDNA content in serum samples from 116 HBV-related HCC cases and 232 frequency-matched cancer-free HBV controls, and evaluate the retrospective association between mtDNA content and HCC risk using logistic regression and their temporal relationship using a mixed effects model. HCC cases had significantly lower circulating mtDNA content than controls (1.06 versus 2.47, P = 1.7 × 10−5). Compared to HBV patients with higher mtDNA content, those with lower mtDNA content had a significantly increased risk of HCC with an odds ratio (OR) of 2.19 (95% confidence interval [CI] 1.28–3.72, P = 0.004). Quartile analyses revealed a significant dose-dependent effect (Ptrend = 0.001) for this association. In a pilot longitudinal sub-cohort of 14 matched cases-control pairs, we observed a trend of dramatically decreased mtDNA content in cases and slightly decreased mtDNA content in controls, with a significant interaction of case-control status with time (Pinteraction = 0.049). Our findings suggest that circulating mtDNA is a potential novel non-invasive biomarker of HCC risk in HBV patients.