Citations

Purpose Biomarkers can add substantial value to current medical practice by providing an integrated approach to prediction using the genetic makeup of the tumor and the genotype of the patient to guide patient-specific treatment selection. We discuss and evaluate various clinical trial designs for the validation of biomarker-guided therapy. Methods Designs for predictive marker validation are broadly classified as retrospective (ie, using data from previously well-conducted randomized controlled trials [RCTs]) versus prospective (enrichment, unselected, hybrid, or adaptive analysis). We discuss the salient features of each design in the context of real trials. Results Well-designed retrospective analysis from well-conducted prospective RCTs can bring forward effective treatments to marker-defined subgroups of patients in a timely manner (eg, KRAS and colorectal cancer). Enrichment designs are appropriate when preliminary evidence suggest that patients with or without that marker profile do not benefit from the treatments in question; however, this may sometimes leave questions unanswered (eg, trastuzumab and breast cancer). An unselected design is optimal where preliminary evidence regarding treatment benefit and assay reproducibility is uncertain (eg, epidermal growth factor receptor and lung cancer). Hybrid designs are appropriate when preliminary evidence demonstrate the efficacy of certain treatments for a marker-defined subgroup, making it unethical to randomly assign patients with that marker status to other treatments (eg, multigene assay and breast cancer). Adaptive analysis designs allow for prespecified marker-defined subgroup analyses of data from an RCT. Conclusion The implementation of these design strategies will lead to a more rapid clinical validation of biomarker-guided therapy.

Purpose Intensive postoperative surveillance is associated with improved survival and recommended for patients with late stage (stage IIB and III) colon cancer. We hypothesized that stage I and IIA colon cancer patients would experience similar benefits. Patients and Methods Secondary analysis of data from the Clinical Outcomes of Surgical Therapy trial was performed by analyzing results according to TNM stage; early (stage I and IIA, 537 patients) and late (stage IIB and III, 254 patients) stage disease. Five-year recurrence rates were higher in patients with late (35.7%) versus early stage disease (9.5%). Early and late stage salvage rates, recurrence patterns and methods of first detection were compared by χ2 test. Results Salvage rates for early- and late-stage disease patients with recurrence were the same (35.9% v 37%; P = .9, respectively). Median survival after second surgery after recurrence was 51.2 and 35.8 months for early- and late-stage patients, respectively. Single sites of first recurrence did not significantly differ between early and late stage, but multiple sites of recurrence occurred less often in early-stage patients (3.6% v 28.6%, for early v late, respectively; P < .001). Methods of first detection of recurrence were not significantly different: carcinoembryonic antigen (29.1% v 37.4%), computed tomography scan (23.6% v 26.4%), chest x-ray (7.3% v 12.1%), and colonoscopy (12.7% v 8.8%), for early versus late stage disease, respectively. Conclusion Patients with early-stage colon cancer have similar sites of recurrence, and receive similar benefit from postrecurrence therapy as late-stage patients; implementation of surveillance guidelines for early-stage patients is appropriate.

Abstract Background: Gene amplification leading to overexpression is a common event in breast tumors that is linked to tumor development and progression. The 17q23 region is amplified in &gt;40% of breast tumors and contains several candidate oncogenes. Because common genetic variation in several oncogenes has been associated with cancer risk, we assessed the relevance of common variants in the 17q23 candidate oncogenes to breast cancer. Methods: We investigated 60 polymorphisms in the TUBD1, SEPT4, PRKCA, TBX2, TBX4, TEX14, TLK2, YPEL2, and PPM1E genes from this amplicon for association with breast cancer risk among 798 Caucasian breast cancer cases and 843 unaffected Caucasian controls from the Mayo Clinic. Results: Eight polymorphisms in PRKCA, TBX4, TLK2, and YPEL2 displayed significant dose-response associations with breast cancer risk (Ptrend &lt; 0.05). Of these, PRKCA rs7342847 and TLK2 rs2245092 and rs733025 were also associated with hormone receptor–positive breast cancer: PRKCA rs7342847 (odds ratio, 0.7; 95% confidence interval, 0.6-0.9; Ptrend = 0.002) and TLK2 rs733025 and rs2245092 (both: odds ratio, 0.8; 95% confidence interval, 0.7-1.0; Ptrend = 0.03). Interactions between SEPT4 rs758377 and TEX14 rs302864 (Pinteraction = 0.0003) and between TLK2 rs733025 and YPEL2 rs16943468 (Pinteraction = 0.05) for risk of breast cancer were also observed. Conclusion: These findings suggest that single polymorphisms and combinations of polymorphisms within candidate oncogenes from the 17q23 amplicon may influence risk of breast cancer overall and possibly specific molecular subtypes of breast tumors. The findings are discussed within the context of the results from two independent data sets. (Cancer Epidemiol Biomarkers Prev 2009;18(6):1864–8)

Abstract Experimental autoimmune encephalomyelitis (EAE) is a T cell-mediated autoimmune disease of the CNS. Metformin is the most widely used drug for diabetes and mediates its action via activating AMP-activated protein kinase (AMPK). We provide evidence that metformin attenuates the induction of EAE by restricting the infiltration of mononuclear cells into the CNS, down-regulating the expression of proinflammatory cytokines (IFN-γ, TNF-α, IL-6, IL-17, and inducible NO synthase (iNOS)), cell adhesion molecules, matrix metalloproteinase 9, and chemokine (RANTES). Furthermore, the AMPK activity and lipids alterations (total phospholipids and in free fatty acids) were restored by metformin treatment in the CNS of treated EAE animals, suggesting the possible involvement of AMPK. Metformin activated AMPK in macrophages and thereby inhibited biosynthesis of phospholipids as well as neutral lipids and also down-regulated the expression of endotoxin (LPS)-induced proinflammatory cytokines and their mediators (iNOS and cyclooxygenase 2). It also attenuated IFN-γ and IL-17-induced iNOS and cyclooxygenase 2 expression in RAW267.4 cells, further supporting its anti-inflammatory property. Metformin inhibited T cell-mediated immune responses including Ag-specific recall responses and production of Th1 or Th17 cytokines, while it induced the generation of IL-10 in spleen cells of treated EAE animals. Altogether these findings reveal that metformin may have a possible therapeutic value for the treatment of multiple sclerosis and other inflammatory diseases.

Purpose Fluorouracil/leucovorin as the sole therapy for metastatic colorectal cancer (CRC) provides an overall survival of 8 to 12 months. With an increase in surgical resections of metastatic disease and development of new chemotherapies, indirect evidence suggests that outcomes for patients are improving in the general population, although the incremental gain has not yet been quantified. Methods We performed a retrospective review of patients newly diagnosed with metastatic CRC treated at two academic centers from 1990 through 2006. Landmark analysis evaluated the association of diagnosis year and liver resection with overall survival. Additional survival analysis of the Surveillance Epidemiology and End Results (SEER) database evaluated a similar population from 1990 through 2005. Results Two thousand four hundred seventy patients with metastatic CRC at diagnosis received their primary treatment at the two institutions during this time period. Median overall survival for those patients diagnosed from 1990 to 1997 was 14.2 months, which increased to 18.0, 18.6, and 29.3 months for patients diagnosed in 1998 to 2000, 2001 to 2003, and 2004 to 2006, respectively. Likewise, 5-year overall survival increased from 9.1% in the earliest time period to 19.2% in 2001 to 2003. Improved outcomes from 1998 to 2004 were a result of an increase in hepatic resection, which was performed in 20% of the patients. Improvements from 2004 to 2006 were temporally associated with increased utilization of new chemotherapeutics. In the SEER registry, overall survival for the 49,459 identified patients also increased in the most recent time period. Conclusion Profound improvements in outcome in metastatic CRC seem to be associated with the sequential increase in the use of hepatic resection in selected patients (1998 to 2006) and advancements in medical therapy (2004 to 2006).

In this study, 65% (132/195) of level B/C obstetric recommendations are amenable to randomized clinical trials (RCTs) and seven were identified as most needed. The purpose of the survey was to evaluate levels B and C recommendations in obstetric practice bulletins (PBs) regarding the feasibility of performing RCT to elevate each subject to level A evidence. Eleven geographically dispersed physicians with experience in research reviewed levels B and C recommendations for the ethical and logistical feasibility of performing an RCT. In the 35 obstetric PBs, 195 level B/C recommendations were reviewed. The majority considered 47 (24%) topics unethical for an RCT and thought 16 (11%) did not need an RCT, thus leaving 132 (67%) levels B and C recommendations available for an RCT. Two-thirds of levels B and C recommendations in obstetric PB are amenable to RCTs and potentially becoming level A evidence.

Abstract Esophageal adenocarcinoma risk in Barrett's esophagus (BE) is increased 30- to 125-fold versus the general population. Among all BE patients, however, neoplastic progression occurs only once per 200 patient-years. Molecular biomarkers are therefore needed to risk-stratify patients for more efficient surveillance endoscopy and to improve the early detection of progression. We therefore performed a retrospective, multicenter, double-blinded validation study of eight BE progression prediction methylation biomarkers. Progression or nonprogression were determined at 2 years (tier 1) and 4 years (tier 2). Methylation was assayed in 145 nonprogressors and 50 progressors using real-time quantitative methylation-specific PCR. Progressors were significantly older than nonprogressors (70.6 versus 62.5 years; P &lt; 0.001). We evaluated a linear combination of the eight markers, using coefficients from a multivariate logistic regression analysis. Areas under the ROC curve (AUC) were high in the 2-year, 4-year, and combined data models (0.843, 0.829, and 0.840; P &lt; 0.001, &lt;0.001, and &lt;0.001, respectively). In addition, even after rigorous overfitting correction, the incremental AUCs contributed by panels based on the 8 markers plus age versus age alone were substantial (Δ-AUC = 0.152, 0.114, and 0.118, respectively) in all 3 models. A methylation biomarker–based panel to predict neoplastic progression in BE has potential clinical value in improving both the efficiency of surveillance endoscopy and the early detection of neoplasia. [Cancer Res 2009;69(10):4112–5]

Background . Clinicians often use validated risk models to guide treatment decisions for cardiovascular risk reduction. The most common risk models for predicting cardiovascular risk are the UKPDS, Framingham, and Archimedes models. In this article, the authors propose a model to optimize the selection of patients for statin therapy of hypercholesterolemia, for patients with type 2 diabetes, using each of the risk models. For each model, they evaluate the role of age, gender, and metabolic state on the optimal start time for statins. Method . Using clinical data from the Mayo Clinic electronic medical record, the authors construct a Markov decision process model with health states composed of cardiovascular events and metabolic factors such as total cholesterol and high-density lipoproteins. They use it to evaluate the optimal start time of statin treatment for different combinations of cardiovascular risk models and patient attributes. Results . The authors find that treatment decisions depend on the cardiovascular risk model used and the age, gender, and metabolic state of the patient. Using the UKPDS risk model to estimate the probability of coronary heart disease and stroke events, they find that all white male patients should eventually start statin therapy; however, using Framingham and Archimedes models in place of UKPDS, they find that for male patients at lower risk, it is never optimal to initiate statins. For white female patients, the authors also find some patients for whom it is never optimal to initiate statins. Assuming that age 40 is the earliest possible start time, the authors find that the earliest optimal start times for UKPDS, Framingham, and Archimedes are 50, 46, and 40, respectively, for women. For men, the earliest optimal start times are 40, 40, and 40, respectively. Conclusions . In addition to age, gender, and metabolic state, the choice of cardiovascular risk model influences the apparent optimal time for starting statins in patients with diabetes.

Abstract Previous studies have suggested that minor alleles for ERCC4 rs744154, TNF rs361525, CASP10 rs13010627, PGR rs1042838, and BID rs8190315 may influence breast cancer risk, but the evidence is inconclusive due to their small sample size. These polymorphisms were genotyped in more than 30,000 breast cancer cases and 30,000 controls, primarily of European descent, from 30 studies in the Breast Cancer Association Consortium. We calculated odds ratios (OR) and 95% confidence intervals (95% CI) as a measure of association. We found that the minor alleles for these polymorphisms were not related to invasive breast cancer risk overall in women of European descent: ECCR4 per-allele OR (95% CI) = 0.99 (0.97-1.02), minor allele frequency = 27.5%; TNF 1.00 (0.95-1.06), 5.0%; CASP10 1.02 (0.98-1.07), 6.5%; PGR 1.02 (0.99-1.06), 15.3%; and BID 0.98 (0.86-1.12), 1.7%. However, we observed significant between-study heterogeneity for associations with risk for single-nucleotide polymorphisms (SNP) in CASP10, PGR, and BID. Estimates were imprecise for women of Asian and African descent due to small numbers and lower minor allele frequencies (with the exception of BID SNP). The ORs for each copy of the minor allele were not significantly different by estrogen or progesterone receptor status, nor were any significant interactions found between the polymorphisms and age or family history of breast cancer. In conclusion, our data provide persuasive evidence against an overall association between invasive breast cancer risk and ERCC4 rs744154, TNF rs361525, CASP10 rs13010627, PGR rs1042838, and BID rs8190315 genotypes among women of European descent. (Cancer Epidemiol Biomarkers Prev 2009;18(5):1610–6)