The validity of cancer information on death certificates in Norway and the impact of death certificate initiated cases on cancer incidence and survival.

BACKGROUND: Death certificates are an important source of information for cancer registries. The aim of this study was to validate the cancer information on death certificates, and to investigate the effect of including death certificate initiated (DCI) cases in the Cancer Registry of Norway when estimating cancer incidence and survival. METHODS: All deaths in Norway in the period 2011-2015 with cancer mentioned on the death certificates were linked to the cancer registry. Notifications not registered from other sources were labelled death certificate notifications (DCNs), and considered as either cancer or not, based on available information in the registry or from trace-back to another source. RESULTS: From the total of 65 091 cancers mentioned on death certificates in the period 2011-2015, 58,425 (89.8%) were already in the registry. Of the remaining 6 666 notifications, 2 636 (2 129 with cancer as underlying cause) were not regarded to be new cancers, which constitutes 4.0% of all cancers mentioned on death certificates and 39.5% of the DCNs. Inclusion of the DCI cases increased the incidence of all cancers combined by 2.6%, with largest differences for cancers with poorer prognosis and for older age groups. Without validation, including the 2 129 disregarded death certificates would over-estimate the incidence by 1.3%. Including DCI cases decreased the five-year relative survival estimate for all cancer sites combined with 0.5% points. CONCLUSION: In this study, almost 40% of the DCNs were regarded not to be a new cancer case, indicating unreliability of death certificate information for cancers that are not already registered from other sources. The majority of the DCNs where, however, registered as new cases that would have been missed without death certificates. Both including and excluding the DCI cases will potentially bias the survival estimates, but in different directions. This biases were shown to be small in the Cancer Registry of Norway.

A simplified frailty score predicts survival and can aid treatment-intensity decisions in older patients with DLBCL.

Patients with diffuse large B-cell lymphoma (DLBCL) have a median age of 70 years. Yet, empirical knowledge about the treatment of older patients is limited because they are frequently excluded from clinical trials. We aimed to construct a simplified frailty score and examine survival and treatment-related mortality (TRM) according to frailty status and treatment intensity in an older real-world population with DLBCL. All patients aged ≥70 years diagnosed with DLBCL between 2006 and 2016 in southeastern Norway (N = 784) were included retrospectively and divided into training (n = 522) and validation (n = 262) cohorts. We constructed and validated a frailty score based on geriatric assessment variables and examined survival and TRM according to frailty status and treatment. The frailty score identified 3 frailty groups with distinct survival and TRM, independent of established prognostic factors (2-year overall survival [OS]: fit, 82%; unfit, 47%; frail, 14%; P < .001). For fit patients, full-dose R-CHOP (initial dosage >80%) was associated with better survival than attenuated R-CHOP ([R-miniCHOP]; 2-year OS: 86% vs 70%; P = .012), also in adjusted analyses. For unfit and frail patients, full-dose R-CHOP was not superior to R-miniCHOP, whereas an anthracycline-free regimen was associated with poorer survival in adjusted analyses. A simplified frailty score identified unfit and frail patients with a higher risk for death and TRM, which can aid treatment-intensity decisions in older patients with DLBCL. In this study, fit patients benefited from full-dose R-CHOP, whereas unfit and frail patients had no benefit from full-dose R-CHOP over R-miniCHOP. An online calculator for assessment of the frailty score is available at https://wide.shinyapps.io/app-frailty/.

Can different definitions of date of cancer incidence explain observed international variation in cancer survival? An ICBP SURVMARK-2 study.

BACKGROUND: Differences in registration practices across population-based cancer registries may contribute to international variation in survival estimates. In particular, there are variations in recorded date of incidence (DOI) as cancer registries have access to different sources of information and use different rules to determine an official DOI. This study investigates the impact of different DOI rules on cancer survival estimates. MATERIALS AND METHODS: Detailed data on dates of pathological confirmation and hospital admittance were collected from three registries participating in the ICBP SURVMARK-2 project (England, Northern Ireland and Norway). Multiple dates of incidence were determined for each cancer patient diagnosed during 2010-2014 by applying three sets of rules that prioritize either: a) histological date, b) hospital admittance date or c) the earliest date recorded. For each set of rules and registry, 1- and 5-year net survival were estimated for eight cancer sites (oesophagus, stomach, colon, rectum, liver, pancreas, lung and ovary). RESULTS: The mean difference between different DOIs within a country and cancer site ranged from 0.1-23 days. The variation in 1- and 5-year net survival using different DOIs were generally small for all registries and cancer sites. Only for liver and pancreatic cancer in Norway and ovarian cancer in England, were larger 1-year survival differences, of 2-3 % found. CONCLUSION: In the ongoing discussion of the comparability of survival estimates across registry populations, the use of different DOI definitions can be considered to have a very limited impact.