SSBP2 Variants Are Associated with Survival in Glioblastoma Patients
CLINICAL CANCER RESEARCH
Authors: Xiao, Yuanyuan; Decker, Paul A.; Rice, Terri; McCoy, Lucie S.; Smirnov, Ivan; Patoka, Joseph S.; Hansen, Helen M.; Wiemels, Joe L.; Tihan, Tarik; Prados, Michael D.; Chang, Susan M.; Berger, Mitchel S.; Kosel, Matthew L.; Fridley, Brooke L.; Lachance, Daniel H.; O'Neill, Brian Patrick; Buckner, Jan C.; Thompson, Reid C.; Nabors, Louis Burt; Olson, Jeffrey J.; Brem, Steve; Madden, Melissa H.; Browning, James E.; Wiencke, John K.; Egan, Kathleen M.; Jenkins, Robert B.; Wrensch, Margaret R.
Abstract
Purpose: Glioblastoma is a devastating, incurable disease with few known prognostic factors. Here, we present the first genome-wide survival and validation study for glioblastoma. Experimental Design: Cox regressions for survival with 314,635 inherited autosomal single-nucleotide polymorphisms (SNP) among 315 San Francisco Adult Glioma Study patients for discovery and three independent validation data sets [87 Mayo Clinic, 232 glioma patients recruited from several medical centers in Southeastern United States (GliomaSE), and 115 The Cancer Genome Atlas patients] were used to identify SNPs associated with overall survival for Caucasian glioblastoma patients treated with the current standard of care, resection, radiation, and temozolomide (total n = 749). Tumor expression of the gene that contained the identified prognostic SNP was examined in three separate data sets (total n 619). Genotype imputation was used to estimate hazard ratios (HR) for SNPs that had not been directly genotyped. Results: From the discovery and validation analyses, we identified a variant in single-stranded DNA-binding protein 2 (SSBP2) on 5q14.1 associated with overall survival in combined analyses (HR, 1.64; P = 1.3 x 10(-6)). Expression of SSBP2 in tumors from three independent data sets also was significantly related to patient survival (P = 5.3 x 10(-4)). Using genotype imputation, the SSBP2 SNP rs17296479 had the strongest statistically significant genome-wide association with poorer overall patient survival (HR, 1.79; 95% CI, 1.45-2.22; P = 1.0 x 10(-7)). Conclusion: The minor allele of SSBP2 SNP rs17296479 and the increased tumor expression of SSBP2 were statistically significantly associated with poorer overall survival among glioblastoma patients. With further confirmation, previously unrecognized inherited variations influencing survival may warrant inclusion in clinical trials to improve randomization. Unaccounted for genetic influence on survival could produce unwanted bias in such studies. Clin Cancer Res; 18(11); 3154-62. (C) 2012 AACR.
GSTP1 Promoter Methylation is Associated with Recurrence in Early Stage Prostate Cancer
JOURNAL OF UROLOGY
Authors: Maldonado, Leonel; Brait, Mariana; Loyo, Myriam; Sullenberger, Lauren; Wang, Kevin; Peskoe, Sarah B.; Rosenbaum, Eli; Howard, Roslyn; Toubaji, Antoun; Albadine, Roula; Netto, George J.; Hoque, Mohammad O.; Platz, Elizabeth A.; Sidransky, David
Abstract
Purpose: Recurrent prostate cancer remains a major problem. Staging, grading and prostate specific antigen level at surgery are helpful but still imperfect predictors of recurrence. For this reason there is an imperative need for additional biomarkers that add to the prediction of currently used prognostic factors. Materials and Methods: We evaluated the extent of promoter methylation of genes previously reported as aberrantly methylated in prostate cancer (AIM1, APC, CCND2, GPX3, GSTP1, MCAM, RAR beta 2, SSBP2 and TIMP3) by quantitative fluorogenic methylation-specific polymerase chain reaction. We used cancer tissue from a nested case-control study of 452 patients surgically treated for prostate cancer. Recurrence cases and controls were compared and the association between methylation extent and recurrence risk was estimated by logistic regression adjusting for patient age at prostatectomy, prostatectomy year, stage, grade, surgical margins and preprostatectomy prostate specific antigen. All statistical tests were 2-sided with p <= 0.05 considered statistically significant. Results: The extent of GSTP1 methylation was higher in patients with recurrence than in controls (p = 0.01), especially patients with early disease, ie organ confined or limited extraprostatic extension (p = 0.001). After multivariate adjustment GSTP1 promoter methylation at or above the median was associated with an increased risk of recurrence, including in men with early disease (each p = 0.05). Conclusions: Greater GSTP1 promoter methylation in cancer tissue was independently associated with the risk of recurrence in patients with early prostate cancer. This suggests that GSTP1 promoter methylation may be a potential tissue based recurrence marker.