Revisiting the Calculation for a Novel Measure of Average Lifespan Shortened: Real-World Examples From Cervical and Ovarian Cancers in Alberta, Canada, 2000 - 2020.

In this technical note, we primarily demonstrate the computation of confidence limits for a novel measure of average lifespan shortened (ALSS). We identified women who had died from cervical and ovarian cancer between 2000 and 2020 from the Alberta cancer registry. Years of life lost (YLL) was calculated using the national life tables of Canada. We estimated the ALSS as a ratio of YLL in relation to the expected lifespan. We computed the confidence limits of the measure using various approaches, including the normal distribution, gamma distribution, and bootstrap method. The new ALSS measure shows a modest gain in lifespan of women, particularly women with ovarian cancer, over the study period.

The Burden of Rare Cancers in North America.

Background: Rare cancers are difficult to study owing to their infrequent diagnosis. Using aggregate incidence data from population-based cancer registries in Europe, the Surveillance of Rare Cancers in Europe project compiled a list of clinically relevant, topography and morphology defined rare cancers operationally defined as having a crude annual incidence rate of <6 per 100,000 persons. In 2020, this list of rare cancers was updated. The objective of this study was to assess the utility of a rare cancer recode variable for use in the Cancer in North America (CiNA) dataset and to provide a first look at the burden of rare cancers in Canada and the United States. Methods: Data were obtained from 62 registries in Canada and the United States that met North American Association of Central Cancer Registries (NAACCR) high-quality data standards. The list of rare cancers was programmed as a Rare Cancer Classification variable within SEER*Stat. SEER*Stat was used to estimate case counts and crude and age-specific incidence rates per 100,000 for cancers diagnosed 2015-2019 by age at diagnosis, country, and country-specific geographic regions in Canada and the United States, and by race/ethnicity in the United States. Results: In Canada and the United States, 21% and 22% of all invasive cancers were classified as rare, respectively. The percentage of rare cancers ranged between 18% to 21% across geographic regions in Canada and the United States. Children (aged 0-14 years) had the highest percentage and lowest incidence rates of rare cancers. The percentage of rare cancers decreased, and incidence increased with increasing age. In the United States, Hispanics had the highest percentage (27%) and non-Hispanic Whites and non-Hispanic Blacks the lowest percentage (21%) of rare cancers. Conclusions: While individual rare cancers are infrequently diagnosed, in aggregate, they account for a substantial percentage of all cancers diagnosed in the population and pose a substantial public health burden. We report variations in percentage of rare cancers by age, and race/ethnicity (United States only). Such variations in the burden of these cancers may suggest possible areas for public health research.

Premature Mortality Due to Malignancies of the Central Nervous System in Canada, 1980-2010.

BACKGROUND: In this study, we investigated whether there has been an improvement in premature mortality due to central nervous system (CNS) cancers among the Canadian population from 1980 through 2010. METHODS: Mortality data for CNS cancers were obtained from World Health Organization mortality database. Years of life lost (YLL) was estimated using Canadian life tables. Average lifespan shortened (ALSS) was calculated and defined as the ratio of YLL relative to the expected lifespan. RESULTS: Over this study period, we observed decreases in age standardized rates to the World Standard Population for mortality due to CNS cancers from 5.3 to 4.1 per 100,000 men, and from 3.6 to 2.9 per 100,000 women. Average YLL decreased from 23.6 to 21.5 years of life among men, and from 27.0 to 23.1 years among women in 1980 and 2010, respectively. The ALSS showed that men with CNS cancers lost 30.1% of their life span and women lost 32.5% in 1980, whereas they lost 25.8 and 26.6% in 2010, respectively. CONCLUSION: Our study shows that -Canadian people with CNS cancers have had their lives prolonged at the end of the study period.

The Impact of Hospital Discharge Linkage on Case Ascertainment of Brain Tumors in the Alberta Cancer Registry, 2010-2015.

BACKGROUND: Concern has been raised regarding the underreporting of nonmalignant central nervous system tumors. This study addressed this issue with 2 objectives: (1) evaluate the impact of linkage with hospital discharges, as recorded in the Discharge Abstract Database (DAD), on supplementing case ascertainment for brain tumors, and (2) identify potential barriers for initial registration of brain tumors in the Alberta Cancer Registry. METHODS: All patients with a brain tumor diagnosed and residing in Alberta from 2010 to 2015 were extracted, after the DAD review, from the Alberta Cancer Registry (ACR). Descriptive statistics were compiled by behavior and type of registration (originally registered or identified through DAD). The total number of expected nonmalignant brain tumors was estimated by applying the Central Brain Tumor Registry of the United States (CBTRUS) incidence rates to the Alberta population and this estimate was compared to observed numbers. Phi coefficients and χ2 tests for the homogeneity of proportions were conducted to examine bivariate relationships of the characteristics of interest. Multiple logistic regression was used to summarize the independent effects on the probability of being identified through DAD. RESULTS: The results show 5% of malignant and 35% of nonmalignant brain tumors were identified through DAD review. When comparing observed to expected number of nonmalignant cases after DAD review, the ACR ultimately captured 76% of those expected. Identification through DAD was statistically significantly (P ≤ .05) associated with patients over 75 years old at diagnosis (odds ratio [OR], 2.5), tumors of benign behavior (OR, 2.6), location at diagnosis in Northern Alberta (OR, 1.5), nonmicroscopically confirmed tumors (OR, 1.3), no visit to a CancerControl Alberta facility (OR, 8.7) and certain histological subtypes, including cranial and spinal nerve tumors (OR, 1.7). CONCLUSION: The use of hospital discharge data significantly improved nonmalignant brain tumor case ascertainment. Therefore, it is recommended that such reviews be instituted annually in provinces while other techniques (such as reminder letters used in Norway or linkages with radiology or other administrative databases) for improving case ascertainment are explored. Those characteristics identified as potential barriers to registration should be investigated to identify possible process improvements in Alberta.

On Capturing Radiological Diagnoses of Brain Tumors to Provide Complete Population Data in Cancer Registries in Canada.

Nonmalignant brain tumors are underreported by an estimated 60% in Canadian cancer registries. One explanation is that radiology facilities or their databases may not be adequately included in the cancer reporting infrastructure. A multidisciplinary stakeholder team met for 1 day, followed by teleconferences, to discuss the evidence for the importance of incorporating radiology diagnoses in brain tumor reports. A role for the neuroradiologist was delineated in brain tumor diagnosis and in ensuring that radiology report information is available to support cancer case ascertainment in the cancer surveillance system. It was noted that brain tumors identified through imaging are clinically managed depending on the diagnosis and prognosis of the disease, and that patient radiology reports become a part of a larger administrative information system. The proportion of nonmalignant brain tumors diagnosed using histology is lower in the United States (49.3%) than in Canada (59%), suggesting that a higher proportion of cases with nonhistologic (likely radiology) diagnosis are captured by the US system (eg, tumors of the sellar region, cranial and spinal tumors, and tumors of the meninges). Finding a way to use existing electronic radiology reports to identify nonmalignant brain tumors needs to be prioritized. This will require access to electronic radiology reports, as manual reporting is impractical. Once access is achieved, an electronic flag to identify new cases through a natural language processing algorithm could be pursued. As radiologists and cancer registrars become more familiar with each other's mandates and workflow demands, innovative and collaborative solutions to improve case ascertainment for brain and other cancers are likely to emerge.