Assessment of Cancer Screening : A Primer

Cancer screening is a prominent strategy in cancer control in the United States, yet the ability to correctly interpret cancer screening data eludes many researchers, clinicians, and policy makers. This open access primer rectifies that situation by teaching readers, in simple language and with straightforward examples, why and how the population-level cancer burden changes when screening is implemented, and how we assess whether that change is of benefit. This book provides an in-depth look at the many aspects of cancer screening and its assessment, including screening phenomena, performance measures, population-level outcomes, research designs, and other important and timely topics. Concise, accessible, and focused, Assessment of Cancer Screening: A Primer is best suited to those with education or experience in clinical research or public health in the United States - no previous knowledge of cancer screening assessment is necessary. This is the first text dedicated to cancer screening theory and methodology to be published in 20 years. Foreword Preface Acknowledgments Contents Contents Contents 1: Foundations 1.1 Cancer 1.2 Cancer Statistics 1.3 Cancer Screening 1.4 Population-Based Cancer Screening 1.5 Choosing the Cancers for Which We Screen 1.6 Choosing Who to Screen 1.7 The Cancer Screening Process 1.8 Cancer Screening Tests 1.9 Organized Screening Programs Versus Opportunistic Screening 1.10 Benefit Versus Harm 1.11 Efficacy and Effectiveness of Cancer Screening 1.12 Cancer Screening: Turning Healthy People Into Cancer Patients References 2: Behind the Scenes 2.1 A Simple Model of the Natural History of Cancer 2.2 Three Important Phenomena in Screen Detection of Cancer 2.2.1 Lead Time 2.2.2 Length-Weighted Sampling 2.2.3 Overdiagnosis 3: Performance Measures 3.1 The Building Blocks of Performance Measures 3.1.1 Cancer Screening Test Result 3.1.2 Cancer: Present or Not? 3.2 Calculating Cancer Screening Performance Measures 3.2.1 The Formulas 3.2.2 The Relationship Between PPV, NPV, and Prevalence 3.2.3 The Implications of Low PPV 3.2.4 Can PPV Be Improved? 3.3 ROC Curves and AUC 3.3.1 ROC Curves 3.3.2 Calculating AUC 3.4 Performance Measures: Evidence or Not? References 4: Population Measures: Definitions 4.1 Intermediate Outcomes 4.1.1 Cancer Incidence 4.1.2 Calculating a Cancer Incidence Rate: A Fictional Example 4.1.3 Stage Distribution 4.1.4 Case Survival 4.2 Definitive Outcomes 4.2.1 Cause-Specific and all-Cause Mortality 4.2.2 Calculating Mortality Rates: A Fictional Example References 5: Population Measures: Cancer Screening’s Impact 5.1 Cancer Screening’s Impact on Intermediate Outcomes 5.1.1 Cancer Incidence 5.1.2 Cancer Incidence Example 5.1.3 Stage at Diagnosis 5.1.4 Stage at Diagnosis Example 5.1.5 Case Survival 5.1.6 Case Survival Example 5.2 Cancer Screening’s Impact on Definitive Outcomes 5.2.1 Mortality Rates and the Three Screening Phenomena 5.2.2 Cause-Specific Mortality Rates 5.2.3 Sticking Diagnosis, Slippery Linkage, and Assessment of Cancer Screening 5.2.4 Cause of Death Review 5.2.5 Cause-Specific Mortality Rates: Definitive Enough? 5.2.6 All-Cause Mortality References 6: Experimental Research Designs 6.1 An Overview of Experimental Study Designs 6.2 Individual-Level Randomized Controlled Trials of Screening 6.2.1 Design Features 6.2.2 Analysis Features 6.2.3 Strengths and Weaknesses 6.2.4 Example of an Individual-Level Cancer Screening RCT 6.3 Cluster-Level Randomized Controlled Trials of Cancer Screening 6.3.1 Design Features 6.3.2 Analysis Features 6.3.3 Strengths and Weaknesses 6.3.4 Example of a Cluster-Level Cancer Screening RCT 6.4 Pragmatic Randomized Controlled Trials of Cancer Screening 6.4.1 Examples of Pragmatic Cancer Screening RCTs References 7: Observational Research Designs 7.1 An Overview of Observational Study Designs 7.2 Cohort Studies 7.2.1 Design Features 7.2.2 Analysis Features 7.2.3 Strengths and Weaknesses 7.2.4 Variations 7.2.5 Examples of Cancer Screening Cohort Studies 7.3 Case-Control Studies 7.3.1 Design Features 7.3.2 Analysis Features 7.3.3 Strengths and Weaknesses 7.3.4 Example of Case-Control Studies of Cancer Screening 7.4 Ecologic Studies 7.4.1 Design Features 7.4.2 Analysis Features 7.4.3 Strengths and Weaknesses 7.4.4 Variations 7.4.5 Examples of Ecologic Studies of Cancer Screening 7.5 Single-Arm Studies 7.5.1 Design Features 7.5.2 Analysis Features 7.5.3 Strengths and Weaknesses 7.5.4 Variations 7.5.5 Examples of Cancer Screening Single-Arm Studies 7.6 Two-in-One Single-Arm Studies 7.6.1 Design Features 7.6.2 Analysis Features 7.6.3 Strengths and Weaknesses 7.6.4 Examples of Two-in-One Single-Arm Studies 7.7 All Study Designs: Critical Data Elements References 8: Cancer Prevention Screening 8.1 Chapter 1: Foundations 8.2 Chapter 2: Behind the Scenes 8.3 Chapter 3: Performance Measures 8.4 Chapter 4: Population Measures: Definitions 8.5 Chapter 5: Population Measures: Cancer Screening’s Impact 8.6 Chapter 6: Experimental Research Designs 8.7 Chapter 7: Observational Research Designs 8.7.1 Example of a Case-Control Study of Cancer Screening with an Outcome of Invasive Disease References 9: Additional Considerations 9.1 Topics Regarding Data Interpretation 9.1.1 Number Needed to Screen 9.1.2 Generalizability of Results 9.1.3 Concurrent Changes in Treatment 9.2 Topics Regarding Methodology 9.2.1 Microsimulation Modeling 9.2.2 Magnitude of Overdiagnosis 9.2.3 Incidence and Prevalence Screens 9.2.4 Interval Cancers 9.3 Topics Regarding Policy 9.3.1 Selecting a Cancer Screening Interval 9.3.2 De-implementation 9.3.3 Reduction in Advanced-Stage Cancer 9.3.4 Benefit in the Absence of a Mortality Reduction References 10: Closing Thoughts References