A geographic information system-based method for estimating cancer rates in non-census defined geographical areas.

PURPOSE: To address locally relevant cancer-related health issues, health departments frequently need data beyond that contained in standard census area-based statistics. We describe a geographic information system-based method for calculating age-standardized cancer incidence rates in non-census defined geographical areas using publically available data. METHODS: Aggregated records of cancer cases diagnosed from 2009 through 2013 in each of Chicago's 77 census-defined community areas were obtained from the Illinois State Cancer Registry. Areal interpolation through dasymetric mapping of census blocks was used to redistribute populations and case counts from community areas to Chicago's 50 politically defined aldermanic wards, and ward-level age-standardized 5-year cumulative incidence rates were calculated. RESULTS: Potential errors in redistributing populations between geographies were limited to <1.5% of the total population, and agreement between our ward population estimates and those from a frequently cited reference set of estimates was high (Pearson correlation r = 0.99, mean difference = -4 persons). A map overlay of safety-net primary care clinic locations and ward-level incidence rates for advanced-staged cancers revealed potential pathways for prevention. CONCLUSIONS: Areal interpolation through dasymetric mapping can estimate cancer rates in non-census defined geographies. This can address gaps in local cancer-related health data, inform health resource advocacy, and guide community-centered cancer prevention and control.

Safety of Blood Pool Contrast Agent Administration in Children and Young Adults.

OBJECTIVE: The objective of our study was to determine the adverse reaction rate associated with the administration of blood pool contrast material in children and young adults. MATERIALS AND METHODS: A review of the MRI and pharmacy databases identified all patients who received gadofosveset trisodium from October 1, 2011, to June 30, 2014. Patients were classified as having been anesthetized or not anesthetized for the MRI examinations. A review of the electronic medical records identified adverse reactions recorded within 24 hours of contrast administration. The adverse reactions were graded as mild, moderate, or severe. Risk ratios were calculated between the adverse reaction rate experienced by anesthetized patients and that experience by nonanesthetized patients. RESULTS: During the study period, 626 patients (mean age, 11.7 years) received 711 doses of gadofosveset trisodium; 137 adverse reactions were recorded, which yields a 19.3% (137/711) adverse reaction rate. There were 115 adverse reactions experienced by 367 anesthetized patients (31.3%): 93.0% (107/115) were mild and 7.0% (8/115) were moderate. The remaining 22 adverse reactions were experienced by 344 (6.4%) nonanesthetized patients, and 90.9% (20/22) were mild. Three nonanesthetized patients had allergiclike reactions; of these allergiclike reactions, one was mild and two were severe for a severe allergiclike reaction rate of 0.28% (2/711). Severe allergiclike reactions were treated without any adverse outcomes. Anesthetized patients were 5.7 times more likely to experience an adverse event than nonanesthetized patients; most reactions in anesthetized patients were seen after the administration of anesthesia alone. CONCLUSION: Most reactions after gadofosveset trisodium administration in children and young adults are mild; however, severe allergiclike reactions occur, so policies must be in place to treat patients with adverse reactions when using this contrast agent. These data may be useful to centers considering administering gadofosveset trisodium to pediatric patients.

Analysis of an automated background correction method for cardiovascular MR phase contrast imaging in children and young adults.

BACKGROUND: Phase contrast magnetic resonance imaging (MRI) is a powerful tool for evaluating vessel blood flow. Inherent errors in acquisition, such as phase offset, eddy currents and gradient field effects, can cause significant inaccuracies in flow parameters. These errors can be rectified with the use of background correction software. OBJECTIVE: To evaluate the performance of an automated phase contrast MRI background phase correction method in children and young adults undergoing cardiac MR imaging. MATERIALS AND METHODS: We conducted a retrospective review of patients undergoing routine clinical cardiac MRI including phase contrast MRI for flow quantification in the aorta (Ao) and main pulmonary artery (MPA). When phase contrast MRI of the right and left pulmonary arteries was also performed, these data were included. We excluded patients with known shunts and metallic implants causing visible MRI artifact and those with more than mild to moderate aortic or pulmonary stenosis. Phase contrast MRI of the Ao, mid MPA, proximal right pulmonary artery (RPA) and left pulmonary artery (LPA) using 2-D gradient echo Fast Low Angle SHot (FLASH) imaging was acquired during normal respiration with retrospective cardiac gating. Standard phase image reconstruction and the automatic spatially dependent background-phase-corrected reconstruction were performed on each phase contrast MRI dataset. Non-background-corrected and background-phase-corrected net flow, forward flow, regurgitant volume, regurgitant fraction, and vessel cardiac output were recorded for each vessel. We compared standard non-background-corrected and background-phase-corrected mean flow values for the Ao and MPA. The ratio of pulmonary to systemic blood flow (Qp:Qs) was calculated for the standard non-background and background-phase-corrected data and these values were compared to each other and for proximity to 1. In a subset of patients who also underwent phase contrast MRI of the MPA, RPA, and LPA a comparison was made between standard non-background-corrected and background-phase-corrected mean combined flow in the branch pulmonary arteries and MPA flow. All comparisons were performed using the Wilcoxon sign rank test (α = 0.05). RESULTS: Eighty-five children and young adults (mean age 14 years; range 10 days to 32 years) met the criteria for inclusion. Background-phase-corrected mean flow values for the Ao and MPA were significantly lower than those for non-background-corrected standard Ao (P = 0.0004) and MPA flow values (P < 0.0001), respectively. However, no significant difference was seen between the standard non-background (P = 0.295) or background-phase-corrected (P = 0.0653) mean Ao and MPA flow values. Neither the mean standard non-background-corrected (P = 0.408) nor the background-phase-corrected (P = 0.0684) Qp:Qs was significantly different from 1. However in the 27 patients with standard non-background-corrected data, the difference between the Ao and MPA flow values was greater than 10%. There were 19 patients with background-phase-corrected data in which the difference between the Ao and MPA flow values was greater than 10%. In the subset of 43 patients who underwent MPA and branch pulmonary artery phase contrast MRI, the sum of the standard non-background-corrected mean RPA and LPA flow values was significantly different from the standard non-background-corrected mean MPA flow (P = 0.0337). The sum of the background-phase-corrected mean RPA and LPA flow values was not significantly different from the background-phase-corrected mean MPA flow value (P = 0.1328), suggesting improvement in pulmonary artery flow calculations using background-phase-correction. CONCLUSION: Our data suggest that background phase correction of phase contrast MRI data does not significantly change Qp:Qs quantification, and there are residual errors in expected Qp:Qs quantification despite background phase correction. However the use of background phase correction does improve quantification of MPA flow relative to combined RPA and LPA flow. Further work is needed to validate these findings in other patient populations, using other MRI units, and across vendors.

Sources of selection and information biases when using commercial database-derived residential histories for cancer research.

PURPOSE: This study examined potential sources of selection and information biases when using residence history information from a commercial database to construct residential histories for cancer research. METHODS: We searched the LexisNexis database for residence data on 3473 adults diagnosed with cancers of the prostate, colon/rectum, and female breast in a single health-care system between 2005 and 2016 using the name and address at diagnosis and the birth date. Residential histories were generated from the results using open-source statistical programs from the National Cancer Institute. Multivariable regression models analyzed the associations of the search results with demographic characteristics and all-cause mortality. RESULTS: Racial/ethnic minorities were less likely to match to vendor residence data compared with non-Hispanic whites (odd ratios [95% confidence intervals (CIs)] for non-Hispanic blacks, Hispanics, and Asian/Pacific Islander were 1.66 [1.30, 2.12], 2.92 [2.18, 3.90], and 4.53 [2.72, 7.55], respectively). Being non-Hispanic black was negatively associated with years of residential history (vs. non-Hispanic whites, ß coefficient [95% CI] = -2.57 [-3.40, -1.73]). Not matching to residence data was associated with an increased 5-year odds of death from any cause (vs. matched subjects, odd ratios [95% CI] = 5.92 [4.29, 8.50]). CONCLUSIONS: Differential ascertainment of residence history by race/ethnicity and association of ascertainment with prognosis are potential sources of selection and information biases when using residence data from a commercial database.

Spatial access to primary care providers and colorectal cancer-specific survival in Cook County, Illinois.

BACKGROUND: Spatial access to primary care has been associated with late-stage and fatal breast cancer, but less is known about its relation to outcomes of other screening-preventable cancers such as colorectal cancer. This population-based retrospective cohort study examined whether spatial access to primary care providers associates with colorectal cancer-specific survival. METHODS: Approximately 26 600 incident colorectal cancers diagnosed between 2000 and 2008 in adults residing in Cook County, Illinois were identified through the state cancer registry and georeferenced to the census tract of residence at diagnosis. An enhanced two-step floating catchment area method measured tract-level access to primary care physicians (PCPs) in the year of diagnosis using practice locations obtained from the American Medical Association. Vital status and underlying cause of death were determined using the National Death Index. Fine-Gray proportional subdistribution hazard models analyzed the association between tract-level PCP access scores and colorectal cancer-specific survival after accounting for tract-level socioeconomic status, case demographics, tumor characteristics, and other factors. RESULTS: Increased tract-level access to PCPs was associated with a lower risk of death from colorectal cancer (hazard ratio [HR], 95% confidence interval [CI]) = 0.87 [0.79, 0.96], P = .008, highest vs lowest quintile), especially among persons diagnosed with regional-stage tumors (HR, 95% CI = 0.80 [0.69, 0.93], P = .004, highest vs lowest quintile). CONCLUSIONS: Spatial access to primary care providers is a predictor of colorectal cancer-specific survival in Cook County, Illinois. Future research is needed to determine which areas within the cancer care continuum are most affected by spatial accessibility to primary care such as referral for screening, accessibility of screening and diagnostic testing, referral for treatment, and access to appropriate survivorship-related care.