Cancer patient survival in Sweden : theory and application

Cancer patient survival in Sweden is generally increasing, and Sweden compares well in an international perspective. Despite these achievements, there are nevertheless socio-economic and regional differences in survival that need to be addressed to meet the intensions of the Swedish Health and Medical Service Act. The Act emphasises good health and access to care for the entire population where priority shall be given to those in the greatest need of care. The new organisational structure for oncological care that is now being implemented, with Regional Cancer Centres as central nodes in a network in their respective health care region, will hopefully be able to address these inequalities and take the past achievements in cancer patient survival even further. The quality and completeness of the Swedish Cancer Register is high. There are nevertheless areas regarding procedures for reporting incident cases to the regional registries and registration that need to be reviewed as a certain degree of under-report- ing does exist. The under-reporting appears to be systematic rather than random as it is site-specific, increases with age, and non-reported tumours are often without histopa- thological verification. For most uses in epidemiology, the degree of under-reporting will be without significant consequences, but to a varying degree, it will have implica- tions for specific research questions. The accuracy of the cancer register should be monitored on a continuous basis rather than in the ad-hoc fashion that has been done so far. This is also the method recommended by the International Agency for Research on Cancer and in guidelines from the Council for Official Statistics at Statistics Sweden. Two studies in this thesis evaluate period-based and cohort-based analyses ability to predict long-term survival for recently diagnosed cancer patients. Both studies show that period analysis gives better prediction of the future true survival, particularly when not all of the available information is used for the cohort analysis. The first of these two studies was the first systematic evaluation of period analysis that was independent of the researchers who proposed the method. Previous evaluations had mainly been per- formed using data from the Finnish Cancer Registry. This study had a significant role in demonstrating the utility of period analysis, which has since become an established method in population-based survival analysis. The second study is the first prospective evaluation of the ability of period analysis to predict future survival. Relative survival is defined as the observed survival of the cancer patients divided by the expected survival of a comparable group from the general population, free from the specific cancer under study. However, as expected survival is usually calculated from general population life tables these estimates are biased. This bias is generally ignored since mortality among individuals with a specific cancer is regarded as a small negligible part of the total mortality of the general population. To estimate the size of this bias the Swedish computerised population registers were used to calculate expected survival both including and excluding individuals with cancer. A simple method to correct for this bias using cause of death statistics was also evaluated. The results show that the bias is often sufficiently small to be ignored for most applications, especially for cancers with high or low mortality and for younger age groups. However, for older age groups and for common cancers the bias can be greater than one percent unit, and even larger for all cancer sites combined. The proposed method to correct for this bias seems to work well, and it may often be sufficient to use cause of death statistics for one recent year to gain a satisfactory correction to the bias

Improved survival in both men and women with diabetes between 1980 and 2004 – a cohort study in Sweden

<p>Abstract</p> <p>Background</p> <p>In Sweden, diabetes prevalence is increasing in spite of unchanged incidence, indicating improved survival. In recent US studies mortality in diabetic subjects has decreased over three decades, but only in men. Our aim was to study mortality over time in diabetic subjects.</p> <p>Methods</p> <p>The annual Swedish Living Conditions Survey from 1980 to 2004 has been record-linked to the Cause of Death Register in order to study trends in mortality risk for those reporting diabetes as a chronic illness. Survival and the relative mortality risk within 5 years of follow-up have been calculated for a random sample of men and women aged 40–84 years with (n = 3,589) and without diabetes (n = 85,685) for the period 1980 to 2004. Poisson regression models were used.</p> <p>Results</p> <p>The age-adjusted mortality risk relative to non-diabetics within 5 years of follow-up for men was doubled during all periods. The relative risk for women was initially about 2.5, with a substantial drop in mortality in 1995–1999 to 1.45 although it increased to 1.90 in the last period. Using models that took into consideration the presence of heart disease, hypertension, daily smoking, and socio-economic status at the initial interview did not change the relative mortality risk. The age-adjusted 10-year observed survival rate for men with diabetes increased from 41.4% 1980–1984 to 51.5% in 1995–1999. The observed survival for women increased from 43.7% to 61.0%.</p> <p>Conclusion</p> <p>Survival rates have improved in subjects with diabetes since the early 1980s, more so in women than in men, thereby decreasing the gap to non-diabetic women.</p

Number of siblings and survival from childhood leukaemia : a national register-based cohort study from Sweden

Background: Previous studies suggest worse leukaemia survival for children with siblings, but the evidence is sparse, inconsistent and does not consider clinical factors. We explored the associations between number of siblings in the household, birth order, and survival from childhood acute lymphoid leukaemia (ALL) and acute myeloid leukaemia (AML). Methods: In this nationwide register-based study we included all children aged 1-14, diagnosed with ALL and AML between 1991-mid 2015 in Sweden (n=1692). Using Cox regression models, we estimated hazard ratios (HRs) and 95% confidence intervals (CIs) according to number of siblings and birth order, adjusting for known prognostic and sociodemographic factors. Results: A tendency towards better ALL survival among children with one, or ≥2, siblings was observed, adjHRs (95% CI): 0.73 (0.49-1.10) and 0.63 (0.40-1.00), respectively. However, this was mainly limited to children with low risk profiles. An indication of better AML survival among children with siblings was seen, adjHRs (95% CI) 0.68 (0.36-1.29) and 0.71 (0.34-1.48) but diminished after adjusting for birth order. Conclusion: Our results do not support previous findings that a larger number of siblings is associated with poorer survival. Inconsistencies might be explained by underlying mechanisms that differ between settings, but chance cannot be ruled out.The Swedish Research Council for Health, Working Life and Welfare (contract no. 2013-1072)Accepte

Cohort Profile : The Socioeconomic Consequences in Adult Life After Childhood Cancer in Scandinavia (SALiCCS) Research Programme

Publisher Copyright: Copyright © 2021 Erdmann, Frederiksen, Mogensen, Pedersen, Mader, Talbäck, Bautz, Hirvonen, Kyrönlahti, Korhonen, Hasle, Malila, Madanat-Harjuoja, Feychting and Winther.Introduction: The growing number of survivors of childhood cancer, with many years of life ahead, demonstrates the increasing clinical and public health relevance of investigating the risks of social and socioeconomic impairment after a childhood cancer diagnosis and the life-saving treatment. To enrich understanding of the mental, social and socioeconomic difficulties that childhood cancer survivors may face during their life-course, identify particularly vulnerable survivors and overcome the limitations of previous research, we initiated the Socioeconomic Consequences in Adult Life after Childhood Cancer in Scandinavia (SALiCCS) research programme. Methods: This Nordic cross-border research programme is a collaboration between the Danish Cancer Society, the Finnish Cancer Registry and Karolinska Institutet to investigate a broad range of mental, social and socioeconomic conditions in long-term childhood cancer survivors in Denmark, Finland and Sweden. SALiCCS is based on a registry-based matched cohort design, comprising five-year survivors of cancer diagnosed at ages 0–19 years (1971–2008 in Denmark, 1971–2009 in Finland, 1971–2011 in Sweden), age-, sex- and country-matched population comparisons and sibling comparisons who were followed over time. Outcomes of interest included mental disorders, educational achievements, employment and profession, family life and the need of social security benefits. Individual-level data linkage among various national registries provided the data for the research programme. Results: The SALiCCS core population comprises 21,292 five-year survivors, 103,303 population comparisons and 29,644 siblings as a second comparison group. The most common diagnoses in survivors were central nervous system tumours, leukaemias and lymphomas. Discussion: SALiCCS is the largest, most comprehensive population-based research initiative in this field, based on high-quality registry data with minimal risk of bias. The findings will be informative for evidence-based survivorship care targeting not only somatic late effects but also psychosocial impairments.Peer reviewe

Income disparities between adult childhood cancer survivors and their peers-A register-based cohort study from the SALiCCS research programme.

BACKGROUND Childhood cancer survivors face various adverse consequences. This Nordic register-based cohort study aimed to assess whether survivors of childhood cancer are more likely to have low income than their peers. METHODS We identified 17,392 childhood cancer survivors diagnosed at ages 0 to 19 between 1971 and 2009 with 83,221 age-, sex-, and country-matched population comparisons. Annual disposable income at ages 20 to 50 years was retrieved from statistical offices (for 1990-2017) and categorized into low income and middle/high income. The number of transitions between income categories were assessed using binomial regression analyses. RESULTS The prevalence of annual low income among childhood cancer survivors was 18.1% and 15.6% among population comparisons (risk ratio [RR] 1.17; 95% confidence interval [CI] 1.16-1.18). Compared to population comparisons, childhood cancer survivors were 10% (95% CI 8%-11%) less likely to transition from low to middle/high income and 12% (10%-15%) more likely to transition from middle/high to low income during follow-up. Among those initially in the low income category, survivors were 7% (95% CI 3%-11%) more likely to remain in the low income category. If the initial category was middle/high income, childhood cancer survivors were 10% (95% CI 8%-11%) less likely to remain in the middle/high income and 45% (37%-53%) more likely to transition to the low income category permanently. CONCLUSIONS Childhood cancer survivors are at higher risk for low income in adulthood than their peers. These disparities might be reduced by continued career counseling along with support in managing within the social security system