ESR1 and p53 interactome alteration defines mechanisms of tamoxifen response in luminal breast cancer.

The canonical mechanism behind tamoxifen's therapeutic effect on estrogen receptor α/ESR1+ breast cancers is inhibition of ESR1-dependent estrogen signaling. Although ESR1+ tumors expressing wild-type p53 were reported to be more responsive to tamoxifen (Tam) therapy, p53 has not been factored into choice of this therapy and the mechanism underlying the role of p53 in Tam response remains unclear. In a window-of-opportunity trial on patients with newly diagnosed stage I-III ESR1+/HER2/wild-type p53 breast cancer who were randomized to arms with or without Tam prior to surgery, we reveal that the ESR1-p53 interaction in tumors was inhibited by Tam. This resulted in functional reactivation of p53 leading to transcriptional reprogramming that favors tumor-suppressive signaling, as well as downregulation of oncogenic pathways. These findings illustrating the convergence of ESR1 and p53 signaling during Tam therapy enrich mechanistic understanding of the impact of p53 on the response to Tam therapy.

Genetic Predictors of Chemotherapy-Induced Peripheral Neuropathy from Paclitaxel, Carboplatin and Oxaliplatin: NCCTG/Alliance N08C1, N08CA and N08CB Study.

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.

Genetic Variations and Health-Related Quality of Life (HRQOL): A Genome-Wide Study Approach.

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.

A randomized, double-blind, placebo-controlled trial of testosterone for treatment of postmenopausal women with aromatase inhibitor-induced arthralgias: Alliance study A221102.

PURPOSE: To evaluate the efficacy of testosterone supplementation for improving aromatase inhibitor musculoskeletal symptoms (AIMSS). METHODS: Postmenopausal women experiencing moderate-to-severe arthralgias while taking adjuvant aromatase inhibitors for breast cancer were enrolled in this trial. Initially, patients were randomly allocated to receive either a subcutaneous testosterone pellet versus a placebo pellet. Due to slow accrual, the protocol was modified such that additional participants were randomized to receive either a topical testosterone gel or a placebo gel. Changes in patient-reported joint pain were compared between patients receiving testosterone and those receiving placebo using a two-sample t test. Changes in hot flashes and other vasomotor symptoms were also analyzed. Further analyses were conducted to evaluate whether 27 single nucleotide polymorphisms (SNPs) in 14 genes previously associated with AIMSS were associated with testosterone supplementation benefit. RESULTS: While 64% of patients reported an improvement in joint pain at 3 months, there were no significant differences in average pain or joint stiffness at 3 or 6 months between testosterone and placebo arms. Patients receiving testosterone did report improvements in strength, lack of energy, urinary frequency, and stress incontinence (p < 0.05). The subset of patients receiving subcutaneous testosterone also experienced improvements in hot flashes and mood swings. An inherited variant (rs7984870 CC genotype) in TNFSF11 was more likely to be associated with improvements in hot flashes in patients receiving testosterone. CONCLUSION: The doses of testosterone supplementation used in this study did not significantly improve AIMSS. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01573442.

Pralatrexate in Combination with Oxaliplatin in Advanced Esophagogastric Cancer: A Phase II Trial with Predictive Molecular Correlates.

The purpose of our study was to evaluate the efficacy of a combination of pralatrexate plus oxaliplatin in advanced esophagogastric cancer (EGC), analyze the impact of polymorphisms in folate metabolism pathway genes on toxicity and efficacy of pralatrexate, and to evaluate microRNA profile of tumor epithelium as a predictive biomarker. This was a two-stage trial with a safety lead in cohort and a primary endpoint of overall response rate (ORR). Patients received biweekly intravenous oxaliplatin (85 mg/m2) and pralatrexate (Dose level 1 [D1], 120 mg/m2; dose level-1 [D-1] 100 mg/m2). Single-nucleotide polymorphisms (SNP) in genes encoding proteins involved in pralatrexate metabolism were evaluated in germline DNA. microRNA profiling of the tumor epithelium was performed. ORR was 26%. Dose-limiting toxicities were observed in 2 of 4 patients at D1 and none at D-1. The T>C polymorphism in DHFR rs11951910 was significantly associated with lower progression-free survival (PFS; P ≤ 0.01), whereas the presence of the SLC19A1 rs2838957 G>A polymorphism was associated with improved PFS (P = 0.02). Presence of the GGH rs3780130 A>T and SLC19A1 rs1051266 G>A polymorphisms were significantly associated with better overall survival (OS; P = 0.01), whereas GGH rs7010484 T>C polymorphism was associated significantly with reduced OS (P = 0.04). There was no correlation between epithelial microRNA expression profile with disease progression or response. We conclude that the combination of oxaliplatin and pralatrexate is safe, is well tolerated, and has modest efficacy in advanced EGC. Pharmacogenomic analysis may be relevant to the use of pralatrexate in combination with platinum agents.

Woodchuck VEGF (wVEGF) characteristics: Model for angiogenesis and human hepatocellular carcinoma directed therapies.

Vascular endothelial growth factor (VEGF) stimulates angiogenesis. Human hepatocellular carcinoma (HCC) is a VEGF-driven tumor often associated with chronic hepatitis B or C virus infection. The woodchuck is a well-characterized model of hepatitis B virus related HCC and a valuable tool for translational studies of novel VEGF targeted agents. We cloned the cDNA encoding woodchuck VEGF (wVEGF), transiently expressed it in COS cells and functionally characterized the recombinant protein. The open reading frame of wVEGF contained 645 nucleotides encoding a protein of 214 amino acids. Two protein bands (17 and 25 kDa) were detected in conditioned media of wVEGF expressing COS-1 cells and a single band of 25 kDa was identified in cell lysates. Addition of recombinant wVEGF to COS cells enhanced cell proliferation and stimulated VEGFR2, Akt, ERK1/2, and FAK phosphorylation. Sunitinib, a tyrosine kinase inhibitor, inhibited wVEGF- induced VEGFR2 phosphorylation in a dose-dependent manner. Finally, development of HCC in woodchucks was accompanied by increased laminin and PECAM1 expressing vessels, VEGFR2 expression, increased ligation of VEGF to VEGFR2, and a decrease in collagen IV-positive blood vessels. Our results suggest that woodchuck model can be used further to study angiogenesis and the effect of VEGF directed therapies in human HCC.

NCCTG N0821 (Alliance): a phase II first-line study of pemetrexed, carboplatin, and bevacizumab in elderly patients with advanced nonsquamous non-small-cell lung cancer with good performance status.

BACKGROUND: We hypothesized that the combination of bevacizumab, carboplatin, and pemetrexed will be an effective first-line regimen in fit, elderly patients with nonsquamous non-small-cell lung cancer. METHODS: Treatment-naïve, stage IIIB/IV nonsquamous non-small-cell lung cancer patients more than 70 years old with good performance status (Eastern Cooperative Oncology Group performance status 0-1) and adequate organ function were eligible. Carboplatin area under the curve 6, pemetrexed 500 mg/m, and bevacizumab 15 mg/kg were administered on day 1 of each 21-day cycle (up to six cycles) followed by maintenance pemetrexed and bevacizumab. The primary end point of 6-month progression-free survival rate of at least 70% was assessed using a one-stage binomial design. Quality of life (QOL) questionnaires were administered. Polymorphisms in genes encoding relevant proteins (drug targets, transport, and metabolism proteins) were correlated with treatment outcome. RESULTS: Fifty-seven eligible patients were enrolled. Median age was 74.5 years. Median treatment cycles received was 6. The most common grade 3 or higher non-hematologic adverse events were fatigue (26%) and hypertension (11%); 16% had grade 4 neutropenia and 6.5% had grade 4 thrombocytopenia. Three patients experienced grade 3/4 hemorrhagic events (one pulmonary, two gastrointestinal). Primary end point of PFS6 was 60% (95% confidence interval [CI]: 45.9-73%). Median PFS was 7.0 months (95% CI: 5.9-10.1), median overall survival was 13.7 months (95% CI: 9.4-16.8). Polymorphic KDR and VEGFA variants correlated with survival and toxicity, respectively. There was no significant change in overall QOL scores over time. CONCLUSION: This regimen is feasible and did not decrease the QOL in this study population. However, it did not meet the primary efficacy end point.

Phase II study of perioperative chemotherapy with cisplatin and pemetrexed in non-small-cell lung cancer.

INTRODUCTION: Pathologic complete response (pCR) with neoadjuvant chemotherapy is associated with improved survival in many solid tumors. We evaluated pCR rate of cisplatin with pemetrexed in non-small-cell lung cancer. METHODS: Patients with stages IB to IIIA non-small-cell lung cancer, Eastern Cooperative Oncology Group performance status 0 to 1 were enrolled in this single-arm phase II trial using two-stage design with 90% power to detect pCR rate of more than or equal to 10%. Pretreatment mediastinal lymph node biopsy was required. Patients received three cycles of cisplatin 75 mg/m with pemetrexed 500 mg/m (day 1 every 21 days) preoperatively and additional two cycles within 60 to 80 days after surgery. The primary end point was pCR. Polymorphisms in FPGS, GGH, SLC19A1, and TYMS genes were correlated with treatment outcomes. RESULTS: Thirty-eight patients were enrolled, with median age of 62.5 years. Preoperatively, 26% had squamous histology, and 34% had biopsy-proven N2 involvement. R0 resection was achieved in 94% of the 34 patients who underwent surgery, and 54% had documented N2 clearance. There was no pCR seen. Median disease-free survival (DFS) and overall survival of these patients have not yet been reached in contrast to median of 13.8 and 24.2 months, respectively, in patients with persistent N2 disease (p = 0.3241 and p = 0.1022, respectively). There was a statistically significant association between DFS and postoperative tumor, node, metastasis stage (p = 0.0429), SLC19A1 rs3788189 TT genotype (p = 0.0821), and viable tumor defined as less than or equal to 10% of resected specimen (p = 0.026). CONCLUSION: The primary end point was not met. Patients with N2 clearance, less than or equal to 10% viable tumor in the resected specimen, and SLC19A1 rs3788189 TT genotype have favorable DFS outcomes.

Low 25(OH) vitamin D3 levels are associated with adverse outcome in newly diagnosed, intensively treated adult acute myeloid leukemia.

BACKGROUND: Several studies have suggested that low 25(OH) vitamin D3 levels may be prognostic in some malignancies, but no studies have evaluated their impact on treatment outcome in patients with acute myeloid leukemia (AML). METHODS: Vitamin D levels were evaluated in 97 consecutive, newly diagnosed, intensively treated patients with AML. MicroRNA expression profiles and single nucleotide polymorphisms (SNPs) in the 25(OH) vitamin D3 pathway genes were evaluated and correlated with 25(OH) vitamin D3 levels and treatment outcome. RESULTS: Thirty-four patients (35%) had normal 25(OH) vitamin D3 levels (32-100 ng/mL), 34 patients (35%) had insufficient levels (20-31.9 ng/mL), and 29 patients (30%) had deficient levels (<20 ng/mL). Insufficient/deficient 25(OH) vitamin D3 levels were associated with worse relapse-free survival (RFS) compared with normal vitamin D3 levels. In multivariate analyses, deficient 25(OH) vitamin D3 , smoking, European Leukemia Network genetic group, and white blood cell count retained their statistical significance for RFS. Several microRNAs and SNPs were associated with 25(OH) vitamin D3 levels, although none remained significant after multiple test corrections; one 25(OH) vitamin D3 receptor SNP, rs10783219, was associated with a lower complete remission rate (P = .0442) and with shorter RFS (P = .0058) and overall survival (P = .0011). CONCLUSIONS: It remains to be determined what role microRNA and SNP profiles play in contributing to low 25(OH) vitamin D3 level and/or outcome and whether supplementation will improve outcomes for patients with AML.

Preclinical discovery of candidate genes to guide pharmacogenetics during phase I development: the example of the novel anticancer agent ABT-751.

OBJECTIVE: ABT-751, a novel orally available antitubulin agent, is mainly eliminated as inactive glucuronide (ABT-751G) and sulfate (ABT-751S) conjugates. We performed a pharmacogenetic investigation of ABT-751 pharmacokinetics using in-vitro data to guide the selection of genes for genotyping in a phase I trial of ABT-751. METHODS: UDP-glucuronosyltransferase (UGT) and sulfotransferase (SULT) enzymes were screened for ABT-751 metabolite formation in vitro. Forty-seven cancer patients treated with ABT-751 were genotyped for 21 variants in these genes. RESULTS: UGT1A1, UGT1A4, UGT1A8, UGT2B7, and SULT1A1 were found to be involved in the formation of inactive ABT-751 glucuronide (ABT-751G) and sulfate (ABT-751S). SULT1A1 copy number (>2) was associated with an average 34% increase in ABT-751 clearance (P=0.044), an 18% reduction in ABT-751 AUC (P=0.045), and a 50% increase in sulfation metabolic ratios (P=0.025). UGT1A8 rs6431558 was associated with a 28% increase in glucuronidation metabolic ratios (P=0.022), and UGT1A4*2 was associated with a 65% decrease in ABT-751 C trough (P=0.009). CONCLUSION: These results might represent the first example of a clinical pharmacokinetic effect of the SULT1A1 copy number variant on the clearance of a SULT1A1 substrate. A-priori selection of candidate genes guided by in-vitro metabolic screening enhanced our ability to identify genetic determinants of interpatient pharmacokinetic variability.

Serum vitamin D metabolites in colorectal cancer patients receiving cholecalciferol supplementation: correlation with polymorphisms in the vitamin D genes.

Cholecalciferol (D(3)) supplementation results in variable increases in serum 25(OH)D(3) levels, however, the influence of genetic polymorphisms on these variable responses is unclear. We measured serum 25(OH)D(3), 24,25(OH)(2)D(3), 1,25(OH)2D(3) and VDBP levels in 50 colorectal cancer (CRC) patients before and during 2,000 IU daily oral D(3) supplementation for six months and in 263 archived CRC serum samples. Serum PTH levels and PBMC 24-OHase activity were also measured during D(3) supplementation. TagSNPs in CYP2R1, CYP27A1, CYP27B1, CYP24A1, VDR, and GC genes were genotyped in all patients, and the association between these SNPs and serum vitamin D(3) metabolites levels before and after D(3) supplementation was analyzed. The mean baseline serum 25(OH)D(3) level was less than 32 ng/mL in 65 % of the 313 CRC patients. In the 50 patients receiving D(3) supplementation, serum levels of 25(OH)D(3) increased (p = 0.008), PTH decreased (p = 0.036) and 24,25(OH)(2)D(3), 1,25(OH)(2)D(3), VDBP levels and PBMC 24-OHase activity were unchanged. GC SNP rs222016 was associated with high 25(OH)D(3) and 1,25(OH)(2)D(3) levels at baseline while rs4588 and rs2282679 were associated with lower 25(OH)D(3) and 1,25(OH)(2)D(3) levels both before and after D(3) supplementation. CYP2R1 rs12794714 and rs10500804 SNPs were significantly associated with low 25(OH)D(3) levels after supplementation but not with baseline 25(OH)D(3). Our results show that D(3) supplementation increased 25(OH)D(3) levels in all patients. GC rs4588 and rs2283679 SNPs were associated with increased risk of vitamin D(3) insufficiency and suboptimal increase in 25(OH)D(3) levels after D(3) supplementation. Individuals with these genotypes may require higher D(3) supplementation doses to achieve vitamin D(3) sufficiency.

A randomized phase II study of gemcitabine and carboplatin with or without cediranib as first-line therapy in advanced non-small-cell lung cancer: North Central Cancer Treatment Group Study N0528.

INTRODUCTION: The purpose of this study was to assess the safety and efficacy of gemcitabine and carboplatin with (arm A) or without (arm B) daily oral cediranib as first-line therapy for advanced non-small-cell lung cancer. METHODS: A lead-in phase to determine the tolerability of gemcitabine 1000 mg/m on days 1 and 8, and carboplatin on day 1 at area under curve 5 administered every 21 days with cediranib 45 mg once daily was followed by a 2 (A):1 (B) randomized phase II study. The primary end point was confirmed overall response rate (ORR) with 6-month progression-free survival (PFS6) rate in arm A as secondary end point. Polymorphisms in genes encoding cediranib targets and transport were correlated with treatment outcome. RESULTS: On the basis of the safety assessment, cediranib 30 mg daily was used in the phase II portion. A total of 58 and 29 evaluable patients were accrued to arms A and B. Patients in A experienced more grade 3+ nonhematologic adverse events, 71% versus 45% (p = 0.01). The ORR was 19% (A) versus 20% (B) (p = 1.0). PFS6 in A was 48% (95% confidence interval: 35%-62%), thus meeting the protocol-specified threshold of at least 40%. The median overall survival was 12.0 versus 9.9 months (p = 0.10). FGFR1 rs7012413, FGFR2 rs2912791, and VEGFR3 rs11748431 polymorphisms were significantly associated with decreased overall survival (hazard ratio 2.78-5.01, p = 0.0002-0.0095). CONCLUSIONS: The trial did not meet its primary end point of ORR but met its secondary end point of PFS6. The combination with cediranib 30 mg daily resulted in increased toxicity. Pharmacogenetic analysis revealed an association of FGFR and VEGFR variants with survival.

Genetic sequence variants in vitamin D metabolism pathway genes, serum vitamin D level and outcome in head and neck cancer patients.

Although some studies have reported associations between serum vitamin D level and prognosis in several cancers, others have found associations between genetic sequence variants (GSVs) in the vitamin D metabolism pathway genes and outcomes in various cancers including head and neck cancer (HNC). We comprehensively evaluated the association and interaction of GSVs in vitamin D metabolism pathway genes and their regulatory effects on circulatory serum vitamin D level in HNC outcome. We systemically evaluated the association of 89 tagging and candidate-based GSVs in six major vitamin D metabolism pathway genes (VDR, GC, CYP24A1, CYP27A1, CYP27B1 and CYP2R1) and the circulating serum vitamin D level with overall survival (OS) and second primary cancer (SPC) in 522 Stages I-II radiation-treated patients with HNC. For OS: median follow-up time was 8 years; for SPC, 4.4 years. The most common subsite was the larynx (84%). Three hundred and twelve patients were alive at the end of follow-up for OS. SPCs were diagnosed in 108 patients and were primarily of lung (46%). Serum vitamin D levels were significantly lower in patients carrying the minor alleles of GC:rs4588 and CYP2R1:rs10500804. CYP24A1:rs2296241 was significantly associated with OS and CYP2R1:rs1993116 was with SPC. These two GSVs remained significantly associated after adjusting for serum vitamin D level and important clinical factors. GSVs in the vitamin D metabolism pathway genes were associated with disease outcomes in HNC patients; however, these GSVs are different from those affecting serum vitamin D levels.

A phase I/II study of erlotinib in combination with the anti-insulin-like growth factor-1 receptor monoclonal antibody IMC-A12 (cixutumumab) in patients with advanced non-small cell lung cancer.

INTRODUCTION: This phase I/II study evaluated the safety and antitumor effect of the combination of erlotinib with cixutumumab, a recombinant fully humanized anti-insulin-like growth factor-1 receptor IgG1 monoclonal antibody, in advanced non-small cell lung cancer (NSCLC). METHODS: Patients with advanced NSCLC were treated in an initial safety-lead and drop-down cohorts using erlotinib 150 mg/d with cixutumumab 6 or 5 mg/kg on days 1, 8, 15, and 22 in 28-day cycles (cohorts 1 and 2). Emerging pharmacokinetic data led to an additional cohort (3 + 3 design) with cixutumumab at 15 mg/kg on day 1 in 21-day cycles (cohort 3). RESULTS: Eighteen patients entered the study (6 at 6 mg/kg, 8 at 5 mg/kg, and 4 at 15 mg/kg), with median age of 65 years. Four of six patients at 6 mg/kg experienced dose-limiting toxicities (DLTs), whereas at 5 mg/kg, one of eight patients experienced DLT but three of eight patients still required a dose delay during cycle 1. At 15 mg/kg every 21 days, two of four patients experienced DLTs. In all cohorts, DLTs were either G3 rash or fatigue. Five patients had stable disease as best response and 14 patients had progressive disease. The median progression-free survival was 39 days (range 21-432+ days). Biomarkers analyses showed a trend toward better progression-free survival seen with higher free baseline insulin-like growth factor-1 levels as seen with other insulin-like growth factor-1R inhibitors. CONCLUSIONS: The combinations of cixutumumab at 6 mg/kg every 7 days and 15 mg/kg every 21 days and full-dose erlotinib are not tolerable in unselected patients with NSCLC, as measured by DLT. Cixutumumab at 5 mg/kg every 7 days was tolerable per DLT, but dose delays were common. Efficacy in unselected patients with NSCLC seems to be low.

Dietary vitamin D intake and serum 25-hydroxyvitamin D level in relation to disease outcomes in head and neck cancer patients.

Low pretreatment vitamin D status has been associated with worsened disease outcomes in patients with cancer at various sites. Its prognostic significance in head and neck cancer (HNC) patients has not been studied. Patients with HNC who participated in a randomized trial were evaluated for: (i) total intake of vitamin D from diet and supplements using a validated food frequency questionnaire (all trial participants, n = 540) and (ii) pretreatment serum 25-hydroxyvitamin D through a radioimmunoassay (n = 522). The association of dietary/serum measures of vitamin D status with HNC recurrence, second primary cancer (SPC) incidence, and overall mortality was evaluated using multivariate Cox proportional hazard models. There was no significant association between dietary or serum vitamin D measures and the three HNC outcomes. The hazard ratios (HRs) comparing the highest with the lowest quartile of dietary/supplemental vitamin D intake were 1.10 (95% confidence interval (CI): 0.66-1.84) for recurrence, 1.05 (95% CI: 0.63-1.74) for SPC, and 1.27 (95% CI: 0.87-1.84) for overall mortality. HRs comparing the uppermost to the lowest quartile of serum 25-hydroxyvitamin D levels were 1.12 (95% CI: 0.65-1.93) for recurrence, 0.72 (95% CI: 0.40-1.30) for SPC, and 0.85 (95% CI: 0.57-1.28) for overall mortality. There was no effect modification by cancer stage, season of initial treatment, or trial arm. Among patients with HNC, vitamin D status before treatment does not influence disease outcomes. Our results contrast with those from most published studies, which suggest prognostic significance of vitamin D status in cancer patients at least in subgroups.

Correlation between polymorphisms of the reduced folate carrier gene (SLC19A1) and survival after pemetrexed-based therapy in non-small cell lung cancer: a North Central Cancer Treatment Group-based exploratory study.

PURPOSE: To correlate polymorphisms in genes involved in the transport, activation, and inactivation of pemetrexed with the outcome of patients with advanced non-small cell lung cancer (NSCLC) treated with pemetrexed. EXPERIMENTAL DESIGN: Data from a phase II NSCLC trial evaluating the optimal schedule of gemcitabine and pemetrexed were used. All patients with available DNA were genotyped for polymorphisms in FPGS, GGH, and SLC19A1 genes. Patients with various genotypes were compared for efficacy and adverse events resulting from pemetrexed. RESULTS: Fifty-four patients had genotype results for all polymorphisms studied. Patients with the homozygous variant genotypes for SLC19A1 IVS4(2117) C>T, IVS5(9148) C>A, and wild-type genotype for exon6(2522) C>T had a significantly better overall survival compared with their counterparts (median overall survival in months: 8.9 [CC] versus 14.0 [CT] versus 16.7 [TT]; 9.4 [CC] versus 10.3 [CA] versus 22.7 [AA]; and 22.7 [CC] versus 10.3 [CT] versus 9.4 [TT] respectively; all log rank p = 0.03). Patients with the heterozygous TC genotype for GGH IVS5(1042) T>C had greater rates of confirmed response + stable disease compared with the TT genotype (85% versus 60%; odds ratio = 4.0; p = 0.06). A greater risk for grade 3/4 SGPT (ALT) elevation was observed in patients heterozygous (GA) for the FPGS IVS1 (28) G>A polymorphism compared with the GG genotype (43% versus 13%; odds ratio = 5.0, p = 0.07). All results were largely consistent within patients with nonsquamous (n = 40) histology. CONCLUSION: Polymorphisms in SLC1A91 seem to predict for survival differences in pemetrexed-treated NSCLC. Additionally, polymorphisms in GGH and FPGS have marginal associations with response and adverse event. These results should be validated in larger prospective studies using pemetrexed.

Phase II trial of pemetrexed plus bevacizumab for second-line therapy of patients with advanced non-small-cell lung cancer: NCCTG and SWOG study N0426.

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/m(2) 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.

Structural basis of substrate recognition in thiopurine s-methyltransferase.

Thiopurine S-methyltransferase (TPMT) modulates the cytotoxic effects of thiopurine prodrugs such as 6-mercaptopurine by methylating them in a reaction using S-adenosyl- l-methionine as the donor. Patients with TPMT variant allozymes exhibit diminished levels of protein and/or enzyme activity and are at risk for thiopurine drug-induced toxicity. We have determined two crystal structures of murine TPMT, as a binary complex with the product S-adenosyl- l-homocysteine and as a ternary complex with S-adenosyl- l-homocysteine and the substrate 6-mercaptopurine, to 1.8 and 2.0 A resolution, respectively. Comparison of the structures reveals that an active site loop becomes ordered upon 6-mercaptopurine binding. The positions of the two ligands are consistent with the expected S N2 reaction mechanism. Arg147 and Arg221, the only polar amino acids near 6-mercaptopurine, are highlighted as possible participants in substrate deprotonation. To probe whether these residues are important for catalysis, point mutants were prepared in the human enzyme. Substitution of Arg152 (Arg147 in murine TPMT) with glutamic acid decreases V max and increases K m for 6-mercaptopurine but not K m for S-adenosyl- l-methionine. Substitution at this position with alanine or histidine and similar substitutions of Arg226 (Arg221 in murine TPMT) result in no effect on enzyme activity. The double mutant Arg152Ala/Arg226Ala exhibits a decreased V max and increased K m for 6-mercaptopurine. These observations suggest that either Arg152 or Arg226 may participate in some fashion in the TPMT reaction, with one residue compensating when the other is altered, and that Arg152 may interact with substrate more directly than Arg226, consistent with observations in the murine TPMT crystal structure.