The National Cancer Database Conforms to the Standardized Framework for Registry and Data Quality.

BACKGROUND: Standardization of procedures for data abstraction by cancer registries is fundamental for cancer surveillance, clinical and policy decision-making, hospital benchmarking, and research efforts. The objective of the current study was to evaluate adherence to the four components (completeness, comparability, timeliness, and validity) defined by Bray and Parkin that determine registries' ability to carry out these activities to the hospital-based National Cancer Database (NCDB). METHODS: Tbis study used data from U.S. Cancer Statistics, the official federal cancer statistics and joint effort between the Centers for Disease Control and Prevention (CDC) and the National Cancer Institute (NCI), which includes data from National Program of Cancer Registries (NPCR) and Surveillance, Epidemiology, and End Results (SEER) to evaluate NCDB completeness between 2016 and 2020. The study evaluated comparability of case identification and coding procedures. It used Commission on Cancer (CoC) standards from 2022 to assess timeliness and validity. RESULTS: Completeness was demonstrated with a total of 6,828,507 cases identified within the NCDB, representing 73.7% of all cancer cases nationwide. Comparability was followed using standardized and international guidelines on coding and classification procedures. For timeliness, hospital compliance with timely data submission was 92.7%. Validity criteria for re-abstracting, recording, and reliability procedures across hospitals demonstrated 94.2% compliance. Additionally, data validity was shown by a 99.1% compliance with histologic verification standards, a 93.6% assessment of pathologic synoptic reporting, and a 99.1% internal consistency of staff credentials. CONCLUSION: The NCDB is characterized by a high level of case completeness and comparability with uniform standards for data collection, and by hospitals with high compliance, timely data submission, and high rates of compliance with validity standards for registry and data quality evaluation.

Survival Among Patients With High-Risk Gastrointestinal Cancers During the COVID-19 Pandemic.

Importance: Prior reports demonstrated that patients with cancer experienced worse outcomes from pandemic-related stressors and COVID-19 infection. Patients with certain malignant neoplasms, such as high-risk gastrointestinal (HRGI) cancers, may have been particularly affected. Objective: To evaluate disruptions in care and outcomes among patients with HRGI cancers during the COVID-19 pandemic, assessing for signs of long-term changes in populations and survival. Design, Setting, and Participants: This retrospective cohort study used data from the National Cancer Database to identify patients with HRGI cancer (esophageal, gastric, primary liver, or pancreatic) diagnosed between January 1, 2018, and December 31, 2020. Data were analyzed between August 23 and September 4, 2023. Main Outcome and Measures: Trends in monthly new cases and proportions by stage in 2020 were compared with the prior 2 years. Kaplan-Meier curves and Cox regression were used to assess 1-year mortality in 2020 compared with 2018 to 2019. Proportional monthly trends and multivariable logistic regression were used to evaluate 30-day and 90-day mortality in 2020 compared with prior years. Results: Of the 156 937 patients included in this study, 54 994 (35.0%) were aged 60 to 69 years and 100 050 (63.8%) were men. There was a substantial decrease in newly diagnosed HRGI cancers in March to May 2020, which returned to prepandemic levels by July 2020. For stage, there was a proportional decrease in the diagnosis of stage I (-3.9%) and stage II (-2.3%) disease, with an increase in stage IV disease (7.1%) during the early months of the pandemic. Despite a slight decrease in 1-year survival rates in 2020 (50.7% in 2018 and 2019 vs 47.4% in 2020), survival curves remained unchanged between years (all P > .05). After adjusting for confounders, diagnosis in 2020 was not associated with increased 1-year mortality compared with 2018 to 2019 (hazard ratio, 0.99; 95% CI, 0.97-1.01). The rates of 30-day (2.1% in 2018, 2.0% in 2019, and 2.1% in 2020) and 90-day (4.3% in 2018, 4.4% in 2019, and 4.6% in 2020) operative mortality also remained similar. Conclusions and Relevance: In this retrospective cohort study, a period of underdiagnosis and increase in stage IV disease was observed for HRGI cancers during the pandemic; however, there was no change in 1-year survival or operative mortality. These results demonstrate the risks associated with gaps in care and the tremendous efforts of the cancer community to ensure quality care delivery during the pandemic. Future research should investigate long-term survival changes among all cancer types as additional follow-up data are accrued.

Data-driven optimization of version 9 American Joint Committee on Cancer staging system for anal cancer.

INTRODUCTION: The American Joint Committee on Cancer (AJCC) staging system undergoes periodic revisions to maintain contemporary survival outcomes related to stage. Recently, the AJCC has developed a novel, systematic approach incorporating survival data to refine stage groupings. The objective of this study was to demonstrate data-driven optimization of the version 9 AJCC staging system for anal cancer assessed through a defined validation approach. METHODS: The National Cancer Database was queried for patients diagnosed with anal cancer in 2012 through 2017. Kaplan-Meier methods analyzed 5-year survival by individual clinical T category, N category, M category, and overall stage. Cox proportional hazards models validated overall survival of the revised TNM stage groupings. RESULTS: Overall, 24,328 cases of anal cancer were included. Evaluation of the 8th edition AJCC stage groups demonstrated a lack of hierarchical prognostic order. Survival at 5 years for stage I was 84.4%, 77.4% for stage IIA, and 63.7% for stage IIB; however, stage IIIA disease demonstrated a 73.0% survival, followed by 58.4% for stage IIIB, 59.9% for stage IIIC, and 22.5% for stage IV (p <.001). Thus, stage IIB was redefined as T1-2N1M0, whereas Stage IIIA was redefined as T3N0-1M0. Reevaluation of 5-year survival based on data-informed stage groupings now demonstrates hierarchical prognostic order and validated via Cox proportional hazards models. CONCLUSION: The 8th edition AJCC survival data demonstrated a lack of hierarchical prognostic order and informed revised stage groupings in the version 9 AJCC staging system for anal cancer. Thus, a validated data-driven optimization approach can be implemented for staging revisions across all disease sites moving forward.

Alterations in Cancer Treatment During the First Year of the COVID-19 Pandemic in the US.

Importance: The COVID-19 pandemic created challenges to the evaluation and treatment of cancer, and abrupt resource diversion toward patients with COVID-19 put cancer treatment on hold for many patients. Previous reports have shown substantial declines in cancer screening and diagnoses in 2020; however, the extent to which the delivery of cancer care was altered remains unclear. Objective: To assess alterations in cancer treatment in the US during the first year of the COVID-19 pandemic. Design, Setting, and Participants: This retrospective cohort study used data from the National Cancer Database (NCDB) on patients older than 18 years with newly diagnosed cancer from January 1, 2018, to December 31, 2020. Main Outcomes and Measures: The main outcomes were accessibility (time to treatment, travel distance, and multi-institutional care), availability (proportional changes in cancer treatment between years), and utilization (reductions by treatment modality, hospital type) of cancer treatment in 2020 compared with 2018 to 2019. Autoregressive models forecasted expected findings for 2020 based on observations from prior years. Results: Of 1 229 654 patients identified in the NCDB in 2020, 1 074 225 were treated for cancer, representing a 16.8% reduction from what was expected. Patients were predominately female (53.8%), with a median age of 66 years (IQR, 57-74 years), similar to demographics in 2018 and 2019. Median time between diagnosis and treatment was 26 days (IQR, 0-36 days) in 2020, and median travel distance for care was 11.1 miles (IQR, 5.0-25.3 miles), similar to 2018 and 2019. In 2020, fewer patients traveled longer distances (20.2% reduction of patients traveling >35 miles). The proportions of patients treated with chemotherapy (32.0%), radiation (29.5%), and surgery (57.1%) were similar to those in 2018 and 2019. Overall, 146 805 fewer patients than expected underwent surgery, 80 480 fewer received radiation, and 68 014 fewer received chemotherapy. Academic hospitals experienced the greatest reduction in cancer surgery and treatment, with a decrease of approximately 484 patients (-19.0%) per hospital compared with 99 patients (-12.6%) at community hospitals and 110 patients (-12.8%) at integrated networks. Conclusions and Relevance: This study found that among patients diagnosed with cancer in 2020, access and availability of treatment remained intact; however, reductions in treated patients varied across treatment modalities and were greater at academic hospitals than at community hospitals and integrated networks compared with expected values. These results suggest the resilience of cancer service lines and frame the economic losses from reductions in cancer treatment during the pandemic.

Reporting of Circumferential Resection Margin in Rectal Cancer Surgery.

Importance: Circumferential resection margin (CRM) in rectal cancer surgery is a major prognostic indicator associated with local recurrence and overall survival. Facility rates of CRM positivity have recently been established as a new quality measure by the Commission on Cancer (CoC); however, the completeness of CRM status reporting is not well characterized. Objective: To describe the changes in CRM reporting and factors associated with low rates of reporting. Design, Setting, and Participants: A retrospective cohort study was conducted using data from the National Cancer Database between January 2010 and December 2019. Data were analyzed between October 1, 2021, and February 1, 2022. Data from the National Cancer Database included patients diagnosed with nonmetastatic rectal adenocarcinoma receiving surgical treatment at CoC-accredited facilities throughout the US. Exposures: Patient, tumor, and facility-level factors. Facilities were divided by surgical volume, safety-net status, and CoC facility type. Main Outcomes and Measures: Circumferential resection margin missingness rates. Results: A total of 110 571 patients (59.3% men) with rectal adenocarcinoma who underwent curative-intent surgery at 1307 CoC-accredited hospitals were included for analysis. Reporting of CRM improved over the study period, with a mean (SE) missing 12.0% (0.32%) decreased from 16.3% (0.36%). Academic facilities had a higher missingness than other facility types (14.3% vs 10.5%-12.7%; P < .001). Mean (SE) rates of missingness were similar between hospitals of varying volume (lowest quartile: 12.2% [0.93%] vs highest quartile: 12.4% [0.53%]; P = .96). Cases in which fewer than 12 lymph nodes were removed had higher rates of missingness (18.1% vs 11.4%; P < .001). Increased odds of CRM missingness were noted with T category (odds ratio [OR], 1.50; 95% CI, 1.35-1.65) and N category (OR, 2.00; 95% CI, 1.82-2.20). Black race was associated with missingness (OR, 1.13; 95% CI, 1.06-1.14). Conclusion and Relevance: Although CRM positivity reporting has improved over the last decade, the findings of this study suggest there is substantial room for improvement as it becomes a quality standard. Missingness appears to be associated with poor performance on other quality metrics and facility type. This measure appears to be ideal for targeted institution-level feedback to improve quality of care nationally.

Disruption of National Cancer Database Data Models in the First Year of the COVID-19 Pandemic.

Importance: Each year, the National Cancer Database (NCDB) collects and analyzes data used in reports to support research, quality measures, and Commission on Cancer program accreditation. Because data models used to generate these reports have been historically stable, year-to-year variances have been attributed to changes within the cancer program rather than data modeling. Cancer submissions in 2020 were anticipated to be significantly different from prior years because of the COVID-19 pandemic. This study involved a validation analysis of the variances in observed to expected 2020 NCDB cancer data in comparison with 2019 and 2018. Observations: The NCDB captured a total of 1 223 221 overall cancer cases in 2020, a decrease of 14.4% (Δ = -206 099) compared with 2019. The early months of the COVID-19 pandemic (March-May 2020) coincided with a nadir of cancer cases in April 2020 that did not recover to overall prepandemic levels through the remainder of 2020. In the early months of the COVID-19 pandemic, the proportion of early-stage disease decreased sharply overall, while the proportion of late-stage disease increased. However, differences in observed to expected stage distribution in 2020 varied by primary disease site. Statistically significant differences in the overall observed to expected proportions of race and ethnicity, sex, insurance type, geographic location, education, and income were identified, but consistent patterns were not evident. Conclusions and Relevance: Historically stable NCDB data models used for research, administrative, and quality improvement purposes were disrupted during the first year of the COVID-19 pandemic. NCDB data users will need to carefully interpret disease- and program-specific findings for years to come to account for pandemic year aberrations when running models that include 2020.

Evaluation of the Impact of the COVID-19 Pandemic on Reliability of Cancer Surveillance Data in the National Cancer Database.

PURPOSE: This study evaluated the reliability of cancer cases reported to the National Cancer Database (NCDB) during 2020, the first year of the COVID-19 pandemic. METHODS: Total number of cancer cases reported to the NCDB between January 2018 and December 2020 were calculated for all cancers and 21 selected cancer sites. The additive outlier method was used to identify structural breaks in trends compared with previous years. The difference between expected (estimated using the vector autoregressive method) and observed number of cases diagnosed in 2020 was estimated using generalized estimating equation under assumptions of the Poisson distribution for count data. Interrupted time series analysis was used to compare changes in the number of records processed by registrars each month of 2020. All models accounted for seasonality, regional variation, and random error. RESULTS: There was a statistically significant decrease (structural break) in the number of cases diagnosed in April 2020, with no recovery in number of cases during subsequent months, leading to a 12.4% deficit in the number of cases diagnosed during the first year of the pandemic. While the number of cancer records initiated by cancer registrars also decreased, the number of records marked completed increased during the first months of the pandemic. CONCLUSION: There was a significant deficit in the number of cancer diagnoses in 2020 that was not due to cancer registrars' inability to extract data during the pandemic. Future studies can use NCDB data to evaluate the impact of the pandemic on cancer care and outcomes.

Evaluating information loss in the National Cancer Database from cases lost to follow-up.

BACKGROUND AND OBJECTIVES: Cancer registries must focus on data capture which returns value while reducing resource burden with minimal loss of data. Identifying the optimum length of follow-up data collection for patients with cancer achieves this goal. METHODS: A two-step analysis using entropy calculations to assess information gain for each follow-up year, and second-order differences to compare survival outcomes between the defined follow-up periods and lifetime follow-up. A total of 391 567 adult cases, deidentified in the National Cancer Database and diagnosed in 1989. Comparisons examined a subset of 61 908 lung cancer cases, 48 387 colon and rectal cancer cases, and 64 134 breast cancer cases in adults. A total of 4133 pediatric cases were diagnosed in 1989 examining 1065 leukemia cases and 494 lymphoma cases. RESULTS: Annual increases in information gain fell below 1% after 16 years of follow-up for adult cases and 9 years for pediatric cases. Comparison of second-order differences showed 62% of the comparisons were similar between 15 years and lifetime follow-up when examining restricted mean survival time. In addition, 90% of the comparisons were statistically similar when comparing hazard ratios. CONCLUSIONS: Survival analysis using 15 years postdiagnosis follow-up showed minimal differences in information gain compared to lifetime follow-up.

Twenty-Five Years of Cancer Follow-Up; Is the Data Worth the Effort?

BACKGROUND: Substantial resources are dedicated to long-term follow-up within cancer registries; however, the completeness of these data is poorly characterized. Our objectives were to quantify long-term cancer follow-up data completeness and the effort required to collect these data using the National Cancer Database (NCDB). METHODS: To quantify data completeness, patients diagnosed with cancer in 1989 were identified in the NCDB and loss to follow-up rates were assessed for 25 years after diagnosis. To quantify data collection effort, patients diagnosed from 1989 to 2014 who were alive and eligible for follow-up in 2014 were identified and the effort to perform patient follow-up was obtained via a survey of tumor registrars. The effort to perform follow-up beyond various intervals after diagnosis was calculated. RESULTS: In total, 484,201 patients at 958 hospitals were diagnosed with cancer in 1989. After 5 years, 6.5% of patients were lost to follow-up (13.1% of living patients), 50.3% were deceased, and 43.2% had ongoing follow-up. After 15 years, 22.9% were lost to follow-up (68.7% of living patients), 66.7% were deceased, and 10.5% had ongoing follow-up. By 25 years, loss to follow-up increased to 28.6% (93.7% of living patients), 69.5% were deceased, and 1.9% had ongoing follow-up. In 2014, 522,838 h were spent performing follow-up for 2,091,353 patients at 1456 hospitals who were >15 years from their initial cancer diagnosis. CONCLUSIONS: While 5-year follow-up is excellent in the NCDB, loss to follow-up increases over time. The impact of curtailing data collection is under investigation and follow-up duration requirements will be re-evaluated.

Trends in Patient Volume by Hospital Type and the Association of These Trends With Time to Cancer Treatment Initiation.

Importance: Increasing demand for cancer care may be outpacing the capacity of hospitals to provide timely treatment, particularly at referral centers such as National Cancer Institute (NCI)-designated and academic centers. Whether the rate of patient volume growth has strained hospital capacity to provide timely treatment is unknown. Objective: To evaluate trends in patient volume by hospital type and the association between a hospital's annual patient volume growth and time to treatment initiation (TTI) for patients with cancer. Design, Setting, and Participants: This retrospective, hospital-level, cross-sectional study used longitudinal data from the National Cancer Database from January 1, 2007, to December 31, 2016. Adult patients older than 40 years who had received a diagnosis of 1 of the 10 most common incident cancers and initiated their treatment at a Commission on Cancer-accredited hospital were included. Data were analyzed between December 19, 2019, and March 27, 2020. Exposures: The mean annual rate of patient volume growth at a hospital. Main Outcomes and Measures: The main outcome was TTI, defined as the number of days between diagnosis and the first cancer treatment. The association between a hospital's mean annual rate of patient volume growth and TTI was assessed using a linear mixed-effects model containing a patient volume × time interaction. The mean annual change in TTI over the study period by hospital type was estimated by including a hospital type × time interaction term. Results: The study sample included 4 218 577 patients (mean [SD] age, 65.0 [11.4] years; 56.6% women) treated at 1351 hospitals. From 2007 to 2016, patient volume increased 40% at NCI centers, 25% at academic centers, and 8% at community hospitals. In 2007, the mean TTI was longer at NCI and academic centers than at community hospitals (NCI: 50 days [95% CI, 48-52 days]; academic: 43 days [95% CI, 42-44 days]; community: 37 days [95% CI, 36-37 days]); however, the mean annual increase in TTI was greater at community hospitals (0.56 days; 95% CI, 0.49-0.62 days) than at NCI centers (-0.73 days; 95% CI, -0.95 to -0.51 days) and academic centers (0.14 days; 95% CI, 0.03-0.26 days). An annual volume growth rate of 100 patients, a level observed at less than 1% of hospitals, was associated with a mean increase in TTI of 0.24 days (95% CI, 0.18-0.29 days). Conclusions and Relevance: In this cross-sectional study, from 2007 to 2016, across the studied cancer types, patients increasingly initiated their cancer treatment at NCI and academic centers. Although increases in patient volume at these centers outpaced that at community hospitals, faster growth was not associated with clinically meaningful treatment delays.

Survival After Cancer Treatment at Top-Ranked US Cancer Hospitals vs Affiliates of Top-Ranked Cancer Hospitals.

Importance: Hospital networks formed around top-ranked cancer hospitals represent an opportunity to optimize complex cancer care in the community. Objective: To compare the short- and long-term survival after complex cancer treatment at top-ranked cancer hospitals and the affiliates of top-ranked hospitals. Design, Setting, and Participants: This cohort study was conducted using data from the unabridged version of the National Cancer Database. Included patients were individuals 18 years or older who underwent surgical treatment for esophageal, gastric, lung, pancreatic, colorectal, or bladder cancer diagnosed between January 1, 2012, and December 31, 2016. Patient outcomes after complex surgical procedures for cancer at top-ranked cancer hospitals (as ranked in top 50 by US News and World Report) were compared with outcomes at affiliates of top-ranked cancer hospitals (affiliation listed in American Hospitals Association survey and confirmed by search of internet presence). Data were analyzed from July through December 2019. Exposures: Undergoing complex cancer treatment at a top-ranked cancer hospital or an affiliated hospital. Main Outcomes and Measures: The association of affiliate status with short-term survival (ie, 90-day mortality) was compared using logistic regression, and the association of affiliate status with long-term survival was compared using time-to-event models, adjusting for patient demographic, payer, clinical, and treatment factors. Results: Among 119 834 patients who underwent surgical treatment for cancer, 79 981 patients (66.7%) were treated at top-ranked cancer hospitals (median [interquartile range] age, 66 [58-74] years; 40 910 [54.9%] men) and 39 853 patients (33.3%) were treated at affiliate hospitals (median [interquartile range] age, 69 [60-77] years; 19 004 [50.0%] men). In a pooled analysis of all cancer types, adjusted perioperative mortality within 90 days of surgical treatment was higher at affiliate hospitals compared with top-ranked hospitals (odds ratio, 1.67 [95% CI, 1.49-1.89]; P < .001). Adjusted long-term survival following cancer treatment at affiliate hospitals was only 77% that of top-ranked hospitals (time ratio, 0.77 [95% CI, 0.72-0.83]; P < .001). The survival advantage was not fully explained by differences in annual surgical volume, with both long- and short-term survival remaining superior at top-ranked hospitals even after models were adjusted for volume. Conclusions and Relevance: These findings suggest that short- and long-term survival after complex cancer treatment were superior at top-ranked hospitals compared with affiliates of top-ranked hospitals. Further study of cancer care within top-ranked cancer networks could reveal collaborative opportunities to improve survival across a broad contingent of the US population.

Evaluating the role of sentinel lymph node biopsy in patients with DCIS treated with breast conserving surgery.

INTRODUCTION: The role of sentinel lymph node biopsy (SLNB) for patients with ductal carcinoma in-situ (DCIS) is limited given the rarity of nodal metastasis in non-invasive disease. Although SLNB is typically a safe procedure, there are potential complications and associated costs. The purpose of this study is to assess national surgical practice patterns and clinical outcomes with respect to the use of SLNB for DCIS in patients undergoing breast conserving surgery (BCS). METHODS: Case-level data from the National Cancer Data Base (NCDB) was assessed to identify adult patients ≥ 18 with DCIS, who underwent BCS and SLNB. Patient demographics and hospital characteristics were grouped for analytic purposes. A multivariate analysis was performed for patient and hospital characteristics. RESULTS: We identified 15,422 patients with DCIS undergoing BCS in 2015, of which 2,698 (18%) underwent SLNB. A multivariate analysis demonstrated a significant association between greater frequency of SLNB in patients age range of 60-69, receipt of care at a community facility, and higher nuclear grade DCIS. Positive sentinel nodes metastasis was identified in 0.9% patients undergoing BCS and SLNB for DCIS. CONCLUSION: The role of SLNB in patients with DCIS undergoing BCS is limited and does not routinely provide meaningful information or benefit to clinical management. Despite this, nearly one in five patients undergoing BCS for DCIS had lymph node sampling performed. Given the potential increased morbidity and financial implications, this finding represents an opportunity for further education and improvement in patient selection for SLNB.

Compliance with Cancer Quality Measures Over Time and Their Association with Survival Outcomes: The Commission on Cancer's Experience with the Quality Measure Requiring at Least 12 Regional Lymph Nodes to be Removed and Analyzed with Colon Cancer Resections.

BACKGROUND: Many quality measures in cancer care are process measures. The rates of compliance for these measures over time have not been well described, and the relationships between measure compliance and survival are not well understood. METHODS: The National Cancer Database, representing cancer registry data from approximately 1500 Commission on Cancer (CoC) cancer programs, was queried to determine the rates of compliance, with the CoC's colon cancer quality measure requiring 12 regional lymph nodes be removed at resection. Data were assessed in 2003, before the measure was reported to programs, through 2015. Measure compliance and risk-adjusted survival were examined by hospital type. RESULTS: From 2003 to 2015, 544,018 cases of colon cancer were analyzed for number of nodes removed. In 2003, compliance was 52.8% and National Cancer Institute (NCI) centers had the highest compliance rate (69.0%), followed by academic cancer centers (61.9%), comprehensive community hospitals (50.9%), and community hospitals (44.0%). Between 2003 and 2015, compliance improved for all hospital types, although differences remained. Risk-adjusted survival in 2009 was better at NCI centers [hazard ratio (HR) 0.76] than at academic cancer centers (HR 0.90), which had better survivals than comprehensive community programs (HR 0.93) when compared with patients treated at community hospitals. CONCLUSION: After introduction of this quality measure, performance at CoC-accredited hospitals improved over the subsequent 13 years, and survival by hospital type paralleled measure compliance by hospital type. This demonstrated measurement may be associated with improvements in performance, and that there are differences in performance and outcome by hospital type.

Incident Cases Captured in the National Cancer Database Compared with Those in U.S. Population Based Central Cancer Registries in 2012-2014.

BACKGROUND: The National Cancer Database (NCDB) is a hospital-based cancer registry that includes diagnostic, staging, treatment, and outcomes data for newly diagnosed cancer patients in the United States. The NCDB data include 31 million records for patients diagnosed between 1985-2015. A Participant User File based on a subset of these data has been available to researchers at facilities accredited by the Commission on Cancer since 2010. This study aimed to compare the number of incident cancer cases in the NCDB with a national population cancer registry. METHODS: Incident cancer cases in the NCDB in 2012-2014 were compared with the number of cancer cases in the United States Cancer Statistics data for the 2012-2014 diagnosis years. Comparisons were made by primary site and other factors. RESULTS: In 2012-2014, the NCDB captured 72% of the cancer cases in the United States, which was slightly higher than the 67% and 69% reported respectively in two prior assessments. Among the top 10 major cancer sites, the highest coverage (80%) was found for breast cancer, and the lowest was found for melanoma of the skin (52%) and prostate (58%). Colon, bladder, and kidney and renal pelvis cancers had relatively high coverage of 71%, 70% and 78%, respectively, whereas lung and bronchus had slightly lower coverage (65%). CONCLUSIONS: The NCDB coverage of U.S. cancer cases has remained relatively high (72%), but differences remain by cancer site and other factors that should be taken into account by users of the NCDB data.