Adjei, Araba A.

Chemotherapy-induced peripheral neuropathy (CIPN) is a common and potentially permanent adverse effect of chemotherapeutic agents including taxanes such as paclitaxel and platinum-based compounds such as oxaliplatin and carboplatin. Previous studies have suggested that genetics may impact the risk of CIPN. We conducted genome-wide association studies (GWASs) for CIPN in two independent populations who had completed European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ)-CIPN20 assessments (a CIPN-specific 20-item questionnaire which includes three scales that evaluate sensory, autonomic, and motor symptoms). The study population N08Cx included 692 participants from three clinical trials (North Central Cancer Treatment Group (NCCTG) N08C1, N08CA, and N08CB) who had been treated with paclitaxel, paclitaxel plus carboplatin, or oxaliplatin. The primary endpoint for the GWAS was the change from pre-chemotherapy CIPN20 sensory score to the worse score over the following 18 weeks. Study population The Mayo Clinic Breast Disease Registry (MCBDR) consisted of 381 Mayo Clinic Breast Disease Registry enrollees who had been treated with taxane or platinum-based chemotherapy. The primary endpoint for the GWAS assessed was the earliest CIPN20 sensory score available after the completion of chemotherapy. In multivariate model analyses, chemotherapy regimen (p = 3.0 × 10−8) and genetic ancestry (p = 0.007) were significantly associated with CIPN in the N08Cx population. Only age (p = 0.0004) was significantly associated with CIPN in the MCBDR population. The SNP most associated with CIPN was rs56360211 near PDE6C (p =7.92 × 10−8) in N08Cx and rs113807868 near TMEM150C in the MCBDR (p = 1.27 × 10−8). Due to a lack of replication, we cannot conclude that we identified any genetic predictors of CIPN.

Health-related quality of life (HRQOL) is an important prognostic patient-reported outcome in oncology. Because prior studies suggest that HRQOL is, in part, heritable, we performed a GWAS to elucidate genetic factors associated with HRQOL in breast cancer survivors. Physical and mental HRQOL were measured via paper surveys that included the PROMIS-10 physical and mental health domain scales in 1442 breast cancer survivors participating in the Mayo Clinic Breast Disease Registry (MCBDR). In multivariable regression analyses, age and financial concerns were significantly associated with global physical health (age: p = 1.6 × 10−23; financial concerns: p = 4.8 × 10−40) and mental health (age: p = 3.5 × 10−7; financial concerns: p = 2.0 × 10−69). Chemotherapy was associated with worse global mental health (p = 0.01). In the GWAS, none of the SNPs reached the genome-wide association significance threshold of 5 × 10−8 for associations with either global physical or global mental health, however, a cluster of SNPs in SCN10A, particularly rs112718371, appeared to be linked to worse global physical health (p = 5.21 × 10−8). Additionally, SNPs in LMX1B, SGCD, PARP12 and SEMA5A were also moderately associated with worse physical and mental health (p < 10−6). These biologically plausible candidate SNPs warrant further study as possible predictors of HRQOL.

7555 Background: In a retrospective exploratory analysis of E4599, patients (pts) > 70 yo had a higher frequency of and more severe toxicities without apparent survival benefit from the addition of B to C+paclitaxel. We hypothesized that in this pt population, B will have better safety and efficacy profile when used in combination with C+P. Methods: Pts >/= 70 yo with previously untreated stage IIIB/IV (TNM 6th ed) nonsquamous NSCLC, ECOG PS 0-1, measurable disease and adequate organ function were eligible. C at AUC 6, P at 500 mg/m2 and B at 15 mg/kg were administered on day 1 of each 21-day cycle for up to 6 cycles followed by maintenance P+B in patients with CR, PR or SD. The primary endpoint was 6-month progression-free survival (PFS) rate. The treatment would be considered promising based on a single arm one-stage binomial design if 34 or more successes out of 55 patients were observed. This design had an exact significance level of 0.05 at 93% power to detect a true success rate of at least 70%. Polymorphisms in VEGFA, FPGS, GGH, SLC19A1 and TYMS in germline DNA were correlated with treatment outcome. Results: 58 eligible pts were enrolled; 29 males/29 females. Median age was 75. Median treatment cycles received was 6. Grade 3 or higher adverse events (AE) were reported in 49 (85%) pts. There were no treatment-related deaths. The most common grade 3/4 AEs(regardless of attribution) were hypertension (10%), fatigue (28%), dehydration (9%), neutropenia (43%) and thrombocytopenia (21%). There were 3 (5%) grade 3/4 hemorrhagic events. 8 (14%) had grade 4 neutropenia and 3 (5%) had grade 4 thrombocytopenia. Grade 3/4 ischemic/thromboembolic events occurred in 6 pts (10%). Thirty-four out of the first 54 (63%, 95% CI: 48.7-75.7%) evaluable pts met the primary endpoint (4 pts were lost to follow-up prior to 6 months). The confirmed ORR was 37.9% (95% CI: 25.5-51.6%). Median time to treatment failure was 4.8 months (95% CI: 3.9-6.4). Median PFS was 7.1 months (95% CI: 5.9-11.7), median OS was 13.7 months (95% CI: 9.4-15.7). Results of SNP analysis will be presented. Conclusions: C+P+B followed by maintenance P+B is an active and tolerable first-line regimen for elderly patients with good PS.

Purpose To evaluate the efficacy and toxicity of pemetrexed combined with bevacizumab as second-line therapy for patients with advanced non–small-cell lung cancer (NSCLC) and to correlate allelic variants in pemetrexed-metabolizing genes with clinical outcome. Patients and Methods Patients with previously treated NSCLC received pemetrexed (500 mg/m2 intravenous) combined with bevacizumab (15 mg/kg intravenous) every 3 weeks. The primary end point, evaluated using a one-stage Fleming design for detecting a true success rate of at least 70%, was the proportion of patients who were progression free and on treatment at 3 months. Polymorphisms in genes responsible for pemetrexed transport (reduced folate carrier [SLC19A1]) and metabolism (folylpolyglutamate synthase [FPGS] and gamma-glutamyl hydrolase [GGH]) evaluated in germline DNA (blood) were correlated with treatment outcome. Results Forty-eight evaluable patients (14 females and 34 males) received a median of four cycles (range, one to 20 cycles). The most common grade 3 or 4 nonhematologic adverse events (AEs) were fatigue (13%), dyspnea (10%), and thrombosis (10%). Grade 3 or 4 hematologic AEs were neutropenia (19%) and lymphopenia (13%). Twenty-four (57%; 95% CI, 41% to 72%) of the first 42 patients met the success criteria. Median overall survival (OS) and progression-free survival (PFS) times were 8.6 and 4.0 months, respectively. The exon 6 (2522)C→T polymorphism in SLC19A1 correlated with 3-month progression-free status (P = .01) and with PFS (P = .05). The IVS1(1307)C→T polymorphism in GGH correlated with OS (P = .04). Conclusion The study did not meet its primary end point. However, the median PFS time of 4 months is promising. Pharmacogenetic studies in larger cohorts are needed to definitively identify polymorphisms that predict for survival and toxicity of pemetrexed.

Abstract Folylpolyglutamate synthase (FPGS) catalyzes the polyglutamation of folic acid, methotrexate, and pemetrexed to produce highly active metabolites. To characterize genetic variation in the FPGS gene, FPGS, have resequenced the gene in four different ethnic populations. Thirty-four single nucleotide polymorphisms were identified including five nonsynonymous coding single nucleotide polymorphisms that altered the FPGS protein sequence: F13L and V22I polymorphisms in the mitochondrial isoform of FPGS, and R466/424C, A489/447V, and S499/457F polymorphisms, which exist in both the mitochondrial and cytosolic isoforms. When expressed in AuxB1 cells, the A447V cytosolic variant was functionally similar to the wild-type cytosolic (WT Cyt) allozyme, whereas the R424C and S457F cytosolic variants were reduced by ∼2-fold in protein expression compared with WT Cyt (P &lt; 0.01). The intrinsic clearance of glutamate was reduced by 12.3-fold (R424C, P &lt; 0.01) and 6.2-fold (S457F, P &lt; 0.01), whereas the intrinsic clearance of methotrexate was reduced by 4.2-fold (R424C, P &lt; 0.05) and 5.4-fold (S457F, P &lt; 0.05) in these two cytosolic variants when compared with the WT Cyt isoform. Additionally, the in vitro enzyme velocity at saturating pemetrexed concentrations was reduced by 1.6-fold (R424C, P &lt; 0.05) and 2.6-fold (S457F, P &lt; 0.01) compared with WT Cyt. AuxB1 cells harboring these same cytosolic variant allozymes displayed significant increases in the EC50 for folic acid and in the IC50 values for both methotrexate and pemetrexed relative to the WT Cyt form of FPGS. These observations suggest that genetic variations in FPGS may alter the efficacy of antifolate therapy in cancer patients. [Cancer Res 2007;67(18):8772–82]

Abstract Recent experimental evidence has shown that catechol estrogens can be activated through metabolism to form depurinating DNA adducts and thereby initiate cancer. Limited data are available regarding this pathway in epithelial ovarian cancer. We conducted a case-control study of 503 incident epithelial ovarian cancer cases at the Mayo Clinic in Rochester, MN, and Jacksonville, FL, and a 48-county region in North Carolina. Six hundred nine cancer-free controls were frequency matched to the cases on age, race, and residence. After an interview to obtain data on risk factors, a sample of blood was collected for DNA isolation. Subjects were genotyped for seven common single nucleotide polymorphisms in four genes involved in catechol estrogen formation (CYP1A1 and CYP1B1) or conjugation (COMT and SULT1A1). Data were analyzed using logistic regression, stratified by race, and with adjustment for design factors and potential confounders. None of the individual genotypes were significantly associated with ovarian cancer risk. However, an oligogenic model that considered the joint effects of the four candidate genes provided evidence for an association between combinations of these genes and ovarian cancer status (P = 0.015). Although preliminary, this study provides some support for the hypothesis that low-penetrance susceptibility alleles may influence risk of epithelial ovarian cancer.

Abstract Aromatase [cytochrome P450 19 (CYP19)] is a critical enzyme for estrogen biosynthesis, and aromatase inhibitors are of increasing importance in the treatment of breast cancer. We set out to identify and characterize genetic polymorphisms in the aromatase gene, CYP19, as a step toward pharmacogenomic studies of aromatase inhibitors. Specifically, we “resequenced” all coding exons, all upstream untranslated exons plus their presumed core promoter regions, all exon-intron splice junctions, and a portion of the 3′-untranslated region of CYP19 using 240 DNA samples from four ethnic groups. Eighty-eight polymorphisms were identified, resulting in 44 haplotypes. Functional genomic studies were done with the four nonsynonymous coding single nucleotide polymorphisms (cSNP) that we observed, two of which were novel. Those cSNPs altered the following amino acids: Trp39Arg, Thr201Met, Arg264Cys, and Met364Thr. The Cys264, Thr364, and double variant Arg39Cys264 allozymes showed significant decreases in levels of activity and immunoreactive protein when compared with the wild-type (WT) enzyme after transient expression in COS-1 cells. A slight decrease in protein level was also observed for the Arg39 allozyme, whereas Met201 displayed no significant changes in either activity or protein level when compared with the WT enzyme. There was also a 4-fold increase in apparent Km value for Thr364 with androstenedione as substrate. Of the recombinant allozymes, only the double mutant (Arg39Cys264) displayed a significant change from the WT enzyme in inhibitor constant for the aromatase inhibitors exemestane and letrozole. These observations indicate that genetic variation in CYP19 might contribute to variation in the pathophysiology of estrogen-dependent disease.

Purpose We determined the maximum-tolerated dose (MTD) and the dose-limiting toxicities (DLT) of 17-allylamino-17-demethoxygeldanamycin (17-AAG) when infused on days 1, 8, and 15 of a 28-day cycle in advanced solid tumor patients. We also characterized the pharmacokinetics of 17-AAG, its effect on chaperone and client proteins, and whether cytochrome P450 (CYP) 3A5 and NAD(P)H:quinone oxidoreductase 1 (NQO1) polymorphisms affected 17-AAG disposition or toxicity. Patients and Methods An accelerated titration design was used. Biomarkers were measured in peripheral-blood mononuclear cells (PBMCs) at baseline and on days 1 and 15, and pharmacokinetic analysis was performed on day 1 of cycle 1. CYP3A5*3 and NQO1*2 genotypes were determined and correlated with pharmacokinetics and toxicity. Results Twenty-one patients received 52 courses at 11 dose levels. DLTs at 431 mg/m2 were grade 3 bilirubin (n = 1), AST (n = 1), anemia (n = 1), nausea (n = 1), vomiting (n = 1), and myalgias (n = 1). No tumor responses were seen. 17-AAG consistently increased heat shock protein (Hsp) 70 levels in PBMCs. At the MTD, the clearance and half-life (t1/2) of 17-AAG were 11.6 L/h/m2 and 4.15 hours, respectively; whereas the active metabolite 17-aminogeldanamycin had a t1/2 of 7.63 hours. The CYP3A5*3 and NQO1*2 polymorphisms were not associated with 17-AAG toxicity. The CYP3A5*3 polymorphism was associated with higher 17-AAG clearance. Conclusion The MTD of weekly 17-AAG is 308 mg/m2. 17-AAG induced Hsp70 in PBMCs, indicating that Hsp90 has been affected. Further evaluation of 17-AAG is ongoing using a twice-weekly regimen, and this schedule of 17-AAG is being tested in combination with chemotherapy.