Hui Tang

Efficacy of pazopanib in progressive, radioiodine-refractory, metastatic differentiated thyroid cancers: results of a phase 2 consortium study

BACKGROUND Chemotherapy has historically proven ineffective in advanced differentiated thyroid cancers, but the realisation that various tyrosine kinases are activated in the disease suggested a potential therapeutic role for tyrosine-kinase inhibitors. We investigated the safety and efficacy of pazopanib. METHODS This phase 2 trial was done from Feb 22, 2008, to Jan 31, 2009, in patients with metastatic, rapidly progressive, radioiodine-refractory differentiated thyroid cancers. Each patient received 800 mg continuous pazopanib daily in 4-week cycles until disease progression, drug intolerance, or both occurred. Up to two previous therapies were allowed, and measurable disease with radiographic progression in the 6-month period before enrolment was a requirement for inclusion. The primary endpoint was any tumour response, according to the Response Evaluation Criteria in Solid Tumors 1.0. This study is registered with ClinicalTrials.gov, number NCT00625846. FINDINGS 39 patients were enrolled. One patient had received no previous radioiodine therapy and another withdrew consent before treatment. Clinical outcomes could, therefore, be assessed in 37 patients (19 [51%] men, median age 63 years). The study is closed to accrual of new patients, but several enrolled patients are still being treated. Patients received a median of 12 cycles (range 1 to >23, total >383). Confirmed partial responses were recorded in 18 patients (response rate 49%, 95% CI 35-68), with likelihood of response lasting longer than 1 year calculated to be 66%. Maximum concentration of pazopanib in plasma during cycle one was significantly correlated with radiographic response (r=-0·40, p=0·021). 16 (43%) patients required dose reductions owing to adverse events, the most frequent of which (any grade) were fatigue (29 patients), skin and hair hypopigmentation (28), diarrhoea (27), and nausea (27). Two patients who died during treatment had pre-existing contributory disorders. INTERPRETATION Pazopanib seems to represent a promising therapeutic option for patients with advanced differentiated thyroid cancers. The correlation of the patients response and pazopanib concentration during the first cycle might indicate that treatment can be individualised to achieve optimum outcomes. Assessment of pazopanib in an expanded cohort of patients with differentiated thyroid cancer, as well as in cohorts of patients with medullary and anaplastic thyroid cancers, is presently being done. FUNDING National Cancer Institute, supported in part by NCI CA15083 and CM62205.

Correlation of IHC and FISH for ALK Gene Rearrangement in Non-small Cell Lung Carcinoma: IHC Score Algorithm for FISH

Introduction: Accurate, cost-effective methods for testing anaplastic lymphoma kinase gene rearrangement (ALK+) are needed to select patients with non-small cell lung carcinoma for ALK-inhibitor therapy. Fluorescent in situ hybridization (FISH) is used to detect ALK+, but it is expensive and not routinely available. We explored the potential of an immunohistochemistry (IHC) scoring system as an affordable, accessible approach. Methods: One hundred one samples were obtained from an enriched cohort of never-smokers with adenocarcinoma from the Mayo Clinic Lung Cancer Cohort. IHC was performed using the ALK1 monoclonal antibody with ADVANCE detection system (Dako) and FISH with dual-color, break-apart probe (Abbott Molecular) on formalin-fixed, paraffin-embedded tissue. Results: Cases were assessed as IHC score 0 (no staining; n = 69), 1+ (faint cytoplasmic staining, n = 21), 2+ (moderate, smooth cytoplasmic staining; n = 3), or 3+ (intense, granular cytoplasmic staining in ≥10% of tumor cells; n = 8). All IHC 3+ cases were FISH+, whereas 1 of 3 IHC 2+ and 1 of 21 IHC 1+ cases were FISH+. All 69 IHC 0 cases were FISH−. Considering FISH a gold-standard reference in this study, sensitivity and specificity of IHC were 90 and 97.8%, respectively, when 2+ and 3+ were regarded as IHC positive and 0 and 1+ as IHC negative. Conclusions: IHC scoring correlates with FISH and may be a useful algorithm in testing ALK+ by FISH in non-small cell lung carcinoma, similar to human epidermal growth factor-2 testing in breast cancer. Further study is needed to validate this approach.

Genetic variants and risk of lung cancer in never smokers: a genome-wide association study.

BACKGROUND Lung cancer in individuals who have never smoked tobacco products is an increasing medical and public-health issue. We aimed to unravel the genetic basis of lung cancer in never smokers. METHODS We did a four-stage investigation. First, a genome-wide association study of single nucleotide polymorphisms (SNPs) was done with 754 never smokers (377 matched case-control pairs at Mayo Clinic, Rochester, MN, USA). Second, the top candidate SNPs from the first study were validated in two independent studies among 735 (MD Anderson Cancer Center, Houston, TX, USA) and 253 (Harvard University, Boston, MA, USA) never smokers. Third, further replication of the top SNP was done in 530 never smokers (UCLA, Los Angeles, CA, USA). Fourth, expression quantitative trait loci (eQTL) and gene-expression differences were analysed to further elucidate the causal relation between the validated SNPs and the risk of lung cancer in never smokers. FINDINGS 44 top candidate SNPs were identified that might alter the risk of lung cancer in never smokers. rs2352028 at chromosome 13q31.3 was subsequently replicated with an additive genetic model in the four independent studies, with a combined odds ratio of 1.46 (95% CI 1.26-1.70, p=5.94x10(-6)). A cis eQTL analysis showed there was a strong correlation between genotypes of the replicated SNPs and the transcription level of the gene GPC5 in normal lung tissues (p=1.96x10(-4)), with the high-risk allele linked with lower expression. Additionally, the transcription level of GPC5 in normal lung tissue was twice that detected in matched lung adenocarcinoma tissue (p=6.75x10(-11)). INTERPRETATION Genetic variants at 13q31.3 alter the expression of GPC5, and are associated with susceptibility to lung cancer in never smokers. Downregulation of GPC5 might contribute to the development of lung cancer in never smokers. FUNDING US National Institutes of Health; Mayo Foundation.

Temsirolimus and rituximab in patients with relapsed or refractory mantle cell lymphoma: a phase 2 study

BACKGROUND Temsirolimus is a mammalian target of rapamycin (mTOR) inhibitor with single-agent antitumour activity in patients with mantle cell lymphoma. We therefore tested its efficacy and toxicity in combination with rituximab (an antiCD20 antibody) in patients with relapsed or refractory mantle cell lymphoma. METHODS In a phase 2 study, patients (aged ≥18 years) at 35 centres in the USA were given temsirolimus 25 mg/week, and rituximab 375 mg/m(2) per week for 4 weeks during the first cycle and thereafter a single dose of rituximab every other 28-day cycle. Both drugs were administered intravenously. Responding patients after six cycles could continue treatment for a total of 12 cycles, and were then observed without additional maintenance treatment. The primary endpoint was the proportion of patients with either rituximab-sensitive or rituximab-refractory disease who had at least a partial response. The analyses were done on all patients who were treated. The study was registered with ClinicalTrials.gov, number NCT00109967. FINDINGS 71 patients with mantle cell lymphoma were enrolled and 69 were assessable and were included in the final analysis. The overall response rate (ORR) was 59% (41 of 69 patients)-13 (19%) patients had complete responses and 28 (41%) had partial responses. The ORR was 63% (30 of 48; 95% CI 47-76) for rituximab-sensitive patients, and 52% (11 of 21; 30-74) for rituximab-refractory patients. The most common treatment-related grade 3 or 4 adverse events in rituximab-sensitive and rituximab-refractory patients were thrombocytopenia (eight [17%] and eight [38%], respectively), neutropenia (ten [21%] and five [24%], respectively), fatigue (eight [17%] and two [10%], respectively), leucopenia (six [13%] and three [14%], respectively), pneumonia (five [10%] and two [10%], respectively), lymphopenia (five [10%] and two [10%], respectively), pneumonitis (four [8%] and none, respectively), oedema (four [8%] and none, respectively), dyspnoea (three [6%] and two [10%], respectively), and hypertriglyceridaemia (three [6%] and two [10%], respectively). INTERPRETATION mTOR inhibitors in combination with rituximab could have a role in the treatment of patients with relapsed and refractory mantle cell lymphoma. FUNDING National Institutes of Health and the Predolin Foundation.

Gene Networks and microRNAs Implicated in Aggressive Prostate Cancer

Prostate cancer, a complex disease, can be relatively harmless or extremely aggressive. To identify candidate genes involved in causal pathways of aggressive prostate cancer, we implemented a systems biology approach by combining differential expression analysis and coexpression network analysis to evaluate transcriptional profiles using lymphoblastoid cell lines from 62 prostate cancer patients with aggressive phenotype (Gleason grade >or= 8) and 63 prostate cancer patients with nonaggressive phenotype (Gleason grade <or= 5). From 13,935 mRNA genes and 273 microRNAs (miRNA) tested, we identified significant differences in 1,100 mRNAs and 7 miRNAs with a false discovery rate (FDR) of <0.01. We also identified a coexpression module demonstrating significant association with the aggressive phenotype of prostate cancer (P = 3.67 x 10(-11)). The module of interest was characterized by overrepresentation of cell cycle-related genes (FDR = 3.50 x 10(-50)). From this module, we further defined 20 hub genes that were highly connected to other genes. Interestingly, 5 of the 7 differentially expressed miRNAs have been implicated in cell cycle regulation and 2 (miR-145 and miR-331-3p) are predicted to target 3 of the 20 hub genes. Ectopic expression of these two miRNAs reduced expression of target hub genes and subsequently resulted in cell growth inhibition and apoptosis. These results suggest that cell cycle is likely to be a molecular pathway causing aggressive phenotype of prostate cancer. Further characterization of cell cycle-related genes (particularly, the hub genes) and miRNAs that regulate these hub genes could facilitate identification of candidate genes responsible for the aggressive phenotype and lead to a better understanding of prostate cancer etiology and progression.

Tumor B7-H1 and B7-H3 expression in squamous cell carcinoma of the lung

BACKGROUND Pulmonary squamous cell carcinoma has a poor prognosis, and new therapeutic targets are needed. The aberrant expression of the immunomodulatory proteins B7-H1 and B7-H3 by malignant cells may contribute to tumoral immune evasion. Data about the expression of these proteins by squamous cell carcinoma of the lung are limited. MATERIALS AND METHODS Immunohistochemistry for B7-H1 and B7-H3 was performed on 214 resected pulmonary squamous cell carcinoma specimens. RESULTS At the last follow-up, 171 of 214 (80%) of patients were deceased (median survival time, 3.76 years). Forty-two (19.6%) of 214 cases showed positivity with B7-H1, with a range of 5% to 60% of cells that stained positively. A total of 189 (88.3%) of 214 cases showed positivity with B7-H3, with a range of 5% to 80% of cells staining positively. By using multivariate analysis, no degree of B7-H1 or B7-H3 positivity was significantly associated with patient outcome. CONCLUSIONS Although B7-H1 and B7-H3 are not of independent prognostic value, they are commonly expressed on a subset of tumor cells in pulmonary squamous cell carcinomas. Known interaction of the B7-H proteins with cytotoxic T-lymphocyte antigen-4 may make them attractive candidate biomarkers for response to immunomodulatory therapeutics, eg, ipilimumab, and warrants further study.

Worse disease-free survival in never-smokers with ALK+ lung adenocarcinoma

Introduction: The EML4–anaplastic lymphoma kinase (ALK) translocation is a recognized oncogenic driver in non-small cell lung cancer. We investigated immunohistochemistry (IHC) screening with fluorescence in situ hybridization (FISH) confirmation for ALK detection and estimated the prevalence of ALK positivity in our patient cohort of never-smokers, together with differences in clinical outcomes and prognostic factors for patients with ALK-positive and ALK-negative tumors. Methods: We designed a three-phase study (training, validation, and testing) in 300 never-smokers with lung adenocarcinoma from the observational Mayo Clinic Lung Cancer Cohort. Tumor samples were tested using IHC and FISH, and concordance between the methods was assessed. Clinical outcomes were assessed via 5-year progression- or recurrence-free survival from diagnosis. Prognostic factors for ALK-positive tumors and metastases were also investigated. Results: ALK-positive patients were significantly (p < 0.05) younger and had higher grade tumors than ALK-negative patients. ALK positivity was 12.2% by IHC and confirmed at 8.2% of tumors by FISH, with complete concordance between IHC 3+/0 and FISH+/− assessments, respectively. Five-year risk of progression or recurrence was doubled for patients with ALK-positive compared with ALK-negative tumors; ALK-positive tumors also appeared to be associated with a higher risk of brain and liver metastases. Conclusions: Our findings suggest that ALK positivity is associated with a significantly poor outcome in nonsmoking-related adenocarcinoma and that ALK-positive tumors may be associated with an increased risk of brain and liver metastases compared with ALK-negative disease. Consequently, an unmet medical need exists in ALK-positive lung cancer patients, and effective ALK-specific therapies are needed.

Comparison of Error Rates in Single-Arm Versus Randomized Phase II Cancer Clinical Trials

PURPOSE To improve the understanding of the appropriate design of phase II oncology clinical trials, we compared error rates in single-arm, historically controlled and randomized, concurrently controlled designs. PATIENTS AND METHODS We simulated error rates of both designs separately from individual patient data from a large colorectal cancer phase III trials and statistical models, which take into account random and systematic variation in historical control data. RESULTS In single-arm trials, false-positive error rates (type I error) were 2 to 4 times those projected when modest drift or patient selection effects (eg, 5% absolute shift in control response rate) were included in statistical models. The power of single-arm designs simulated using actual data was highly sensitive to the fraction of patients from treatment centers with high versus low patient volumes, the presence of patient selection effects or temporal drift in response rates, and random small-sample variation in historical controls. Increasing sample size did not correct the over optimism of single-arm studies. Randomized two-arm design conformed to planned error rates. CONCLUSION Variability in historical control success rates, outcome drifts in patient populations over time, and/or patient selection effects can result in inaccurate false-positive and false-negative error rates in single-arm designs, but leave performance of the randomized two-arm design largely unaffected at the cost of 2 to 4 times the sample size compared with single-arm designs. Given a large enough patient pool, the randomized phase II designs provide a more accurate decision for screening agents before phase III testing.

Increased miR-708 Expression in NSCLC and Its Association with Poor Survival in Lung Adenocarcinoma from Never Smokers

Purpose: miRNA plays an important role in human disease and cancer. We seek to investigate the expression status, clinical relevance, and functional role of miRNA in non–small cell lung cancer. Experimental Design: We conducted miRNA expression profiling in matched lung adenocarcinoma and uninvolved lung using 56 pairs of fresh-frozen (FF) and 47 pairs of formalin-fixed, paraffin-embedded (FFPE) samples from never smokers. The most differentially expressed miRNA genes were evaluated by Cox analysis and log-rank test. Among the best candidate, miR-708 was further examined for differential expression in two independent cohorts. Functional significance of miR-708 expression in lung cancer was examined by identifying its candidate mRNA target and through manipulating its expression levels in cultured cells. Results: Among the 20 miRNAs most differentially expressed between tested tumor and normal samples, high expression level of miR-708 in the tumors was most strongly associated with an increased risk of death after adjustments for all clinically significant factors including age, sex, and tumor stage (FF cohort: HR, 1.90; 95% CI, 1.08–3.35; P = 0.025 and FFPE cohort: HR, 1.93; 95% CI, 1.02–3.63; P = 0.042). The transcript for TMEM88 gene has a miR-708 binding site in its 3′ UTR and was significantly reduced in tumors high of miR-708. Forced miR-708 expression reduced TMEM88 transcript levels and increased the rate of cell proliferation, invasion, and migration in culture. Conclusions: miRNA-708 acts as an oncogene contributing to tumor growth and disease progression by directly downregulating TMEM88, a negative regulator of the Wnt signaling pathway in lung cancer. Clin Cancer Res; 18(13); 3658–67. ©2012 AACR.

Leukocyte DNA Methylation Signature Differentiates Pancreatic Cancer Patients from Healthy Controls

Pancreatic adenocarcinoma (PaC) is one of most difficult tumors to treat. Much of this is attributed to the late diagnosis. To identify biomarkers for early detection, we examined DNA methylation differences in leukocyte DNA between PaC cases and controls in a two-phase study. In phase I, we measured methylation levels at 1,505 CpG sites in treatment-naïve leukocyte DNA from 132 never-smoker PaC patients and 60 never-smoker healthy controls. We found significant differences in 110 CpG sites (false discovery rate <0.05). In phase II, we tested and validated 88 of 96 phase I selected CpG sites in 240 PaC cases and 240 matched controls (p≤0.05). Using penalized logistic regression, we built a prediction model consisting of five CpG sites (IL10_P348, LCN2_P86, ZAP70_P220, AIM2_P624, TAL1_P817) that discriminated PaC patients from controls (C-statistic = 0.85 in phase I; 0.76 in phase II). Interestingly, one CpG site (LCN2_P86) alone could discriminate resectable patients from controls (C-statistic  = 0.78 in phase I; 0.74 in phase II). We also performed methylation quantitative trait loci (methQTL) analysis and identified three CpG sites (AGXT_P180_F, ALOX12_E85_R, JAK3_P1075_R) where the methylation levels were significantly associated with single nucleotide polymorphisms (SNPs) (false discovery rate <0.05). Our results demonstrate that epigenetic variation in easily obtainable leukocyte DNA, manifested by reproducible methylation differences, may be used to detect PaC patients. The methylation differences at certain CpG sites are partially attributable to genetic variation. This study strongly supports future epigenome-wide association study using leukocyte DNA for biomarker discovery in human diseases.