The association of cancer survival with four socioeconomic indicators: a longitudinal study of the older population of England and Wales 1981-2000

Contrasting socio-economic influences on colorectal cancer incidence and survival in England and Wales

Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the world and second most common cause of cancer death. The relationship between socio-economic deprivation and CRC incidence is unclear and previous findings have been inconsistent. There is stronger evidence of an association between area-level deprivation and CRC survival; however, few studies have investigated the association between individual-level socio-economic status (SES) and CRC survival. Data from the Office for National Statistics Longitudinal Study (LS) in England and Wales was used. LS members aged 50+ were stratified by individual-level educational attainment, social class, housing tenure and area deprivation quintile, measured at the 2001 Census. Time-to-event analysis examined associations between indicators of SES and CRC incidence and survival (all-cause and CRC death), over a 15-year follow-up period. Among 178116 LS members, incidence of CRC was lower among those with a degree, compared to those with no degree and higher among those employed in manual occupations compared to non-manual occupations. No clear relationship was observed between CRC incidence and the area-based measure of deprivation. Disparities were greater for survival. Among 5016 patients diagnosed with CRC aged 50+, probability of death from all-causes was lower among those with a degree, compared to no degree and higher among those employed in manual occupations, compared to non-manual occupations and among those living in social-rented housing, compared to owner-occupiers. Individual indicators of SES were also associated with probability of death from CRC. Those living in the most deprived areas had a higher probability of death (from all-causes and CRC) compared to those in the least deprived areas. Both individual and area-based indicators of SES were associated with CRC survival, and the relationships were stronger than those observed for CRC incidence. These findings could help inform more effective targeting of public health interventions for CRC.

Systematic review of the association between socioeconomic status and bladder cancer survival with hospital type, comorbidities, and treatment delay as mediators

Objectives

Materials and methods

Results

Conclusions

Assessment of the concordance between individual-level and area-level measures of socio-economic deprivation in a cancer patient cohort in England and Wales

OBJECTIVES

Most research on health inequalities uses aggregated deprivation scores assigned to the small area where the patient lives; however, the concordance between aggregate area-level deprivation measures and personal deprivation experienced by individuals living in the area is poorly understood. Our objective was to examine the agreement between individual and ecological deprivation. We tested the concordance between metrics of income, occupation and education at individual and area levels, and assessed the reliability of area-based deprivation measures to predict individual deprivation circumstances.

SETTING

England and Wales.

PARTICIPANTS

A cancer patient cohort of 9547 individuals extracted from the Office for National Statistics Longitudinal Study.

OUTCOMES

We quantified the concordance between measures of income, occupation and education at individual and area level. In addition, we used ROC (receiver operating characteristic) curves and the area under the curve (AUC) to assess the reliability of area-based deprivation measures to predict individual deprivation circumstances.

RESULTS

We found low concordance between individual-level and area-level indicators of deprivation (Cramer's V statistics range between 0.07 and 0.20). The most commonly used indicator in health inequalities research, area-based income deprivation, was a poor predictor of individual income status (AUC between 0.56 and 0.59), whereas education and occupation were slightly better predictors (AUC between 0.62 and 0.65). The results were consistent across sexes and across six major cancer types.

CONCLUSIONS

Our results indicate that ecological deprivation measures capture only part of the relationship between deprivation and health outcomes, especially with respect to income measurement. This has important implications for our understanding of the relationship between deprivation and health, and, as a consequence, healthcare policy. The results have a wide-reaching impact for the way in which we measure and monitor inequalities, and in turn, fund and organise current UK healthcare policy aimed at reducing them.

Geographical Variations in Prostate Cancer Outcomes: A Systematic Review of International Evidence

Background: Previous reviews of geographical disparities in the prostate cancer continuum from diagnosis to mortality have identified a consistent pattern of poorer outcomes with increasing residential disadvantage and for rural residents. However, there are no contemporary, systematic reviews summarizing the latest available evidence. Our objective was to systematically review the published international evidence for geographical variations in prostate cancer indicators by residential rurality and disadvantage.

Methods: Systematic searches of peer-reviewed articles in English published from 1/1/1998 to 30/06/2018 using PubMed, EMBASE, CINAHL, and Informit databases. Inclusion criteria were: population was adult prostate cancer patients; outcome measure was PSA testing, prostate cancer incidence, stage at diagnosis, access to and use of services, survival, and prostate cancer mortality with quantitative results by residential rurality and/or disadvantage. Studies were critically appraised using a modified Newcastle-Ottawa Scale.

Results: Overall 169 studies met the inclusion criteria. Around 50% were assessed as high quality and 50% moderate. Men from disadvantaged areas had consistently lower prostate-specific antigen (PSA) testing and prostate cancer incidence, poorer survival, more advanced disease and a trend toward higher mortality. Although less consistent, predominant patterns by rurality were lower PSA testing, prostate cancer incidence and survival, but higher stage disease and mortality among rural men. Both geographical measures were associated with variations in access and use of prostate cancer-related services for low to high risk disease.

Conclusions: This review found substantial evidence that prostate cancer indicators varied by residential location across diverse populations and geographies. While wide variations in study design limited comparisons across studies, our review indicated that internationally, men living in disadvantaged areas, and to a lesser extent more rural areas, face a greater prostate cancer burden. This review highlights the need for a better understanding of the complex social, environmental, and behavioral reasons for these variations, recognizing that, while important, geographical access is not the only issue. Implementing research strategies to help identify these processes and to better understand the central role of disadvantage to variations in health outcome are crucial to inform the development of evidence-based targeted interventions.

Socioeconomic Differences and Lung Cancer Survival-Systematic Review and Meta-Analysis

Background: The impact of socioeconomic differences on cancer survival has been investigated for several cancer types showing lower cancer survival in patients from lower socioeconomic groups. However, little is known about the relation between the strength of association and the level of adjustment and level of aggregation of the socioeconomic status measure. Here, we conduct the first systematic review and meta-analysis on the association of individual and area-based measures of socioeconomic status with lung cancer survival.

Methods: In accordance with PRISMA guidelines, we searched for studies on socioeconomic differences in lung cancer survival in four electronic databases. A study was included if it reported a measure of survival in relation to education, income, occupation, or composite measures (indices). If possible, meta-analyses were conducted for studies reporting on individual and area-based socioeconomic measures.

Results: We included 94 studies in the review, of which 23 measured socioeconomic status on an individual level and 71 on an area-based level. Seventeen studies were eligible to be included in the meta-analyses. The meta-analyses revealed a poorer prognosis for patients with low individual income (pooled hazard ratio: 1.13, 95 % confidence interval: 1.08–1.19, reference: high income), but not for individual education. Group comparisons for hazard ratios of area-based studies indicated a poorer prognosis for lower socioeconomic groups, irrespective of the socioeconomic measure. In most studies, reported 1-, 3-, and 5-year survival rates across socioeconomic status groups showed decreasing rates with decreasing socioeconomic status for both individual and area-based measures. We cannot confirm a consistent relationship between level of aggregation and effect size, however, comparability across studies was hampered by heterogeneous reporting of socioeconomic status and survival measures. Only eight studies considered smoking status in the analysis.

Conclusions: Our findings suggest a weak positive association between individual income and lung cancer survival. Studies reporting on socioeconomic differences in lung cancer survival should consider including smoking status of the patients in their analysis and to stratify by relevant prognostic factors to further explore the reasons for socioeconomic differences. A common definition for socioeconomic status measures is desirable to further enhance comparisons between nations and across different levels of aggregation.

Describing the association between socioeconomic inequalities and cancer survival: methodological guidelines and illustration with population-based data

BACKGROUND

Describing the relationship between socioeconomic inequalities and cancer survival is important but methodologically challenging. We propose guidelines for addressing these challenges and illustrate their implementation on French population-based data.

METHODS

We analyzed 17 cancers. Socioeconomic deprivation was measured by an ecological measure, the European Deprivation Index (EDI). The Excess Mortality Hazard (EMH), ie, the mortality hazard among cancer patients after accounting for other causes of death, was modeled using a flexible parametric model, allowing for nonlinear and/or time-dependent association between the EDI and the EMH. The model included a cluster-specific random effect to deal with the hierarchical structure of the data.

RESULTS

We reported the conventional age-standardized net survival (ASNS) and described the changes of the EMH over the time since diagnosis at different levels of deprivation. We illustrated nonlinear and/or time-dependent associations between the EDI and the EMH by plotting the excess hazard ratio according to EDI values at different times after diagnosis. The median excess hazard ratio quantified the general contextual effect. Lip-oral cavity-pharynx cancer in men showed the widest deprivation gap, with 5-year ASNS at 41% and 29% for deprivation quintiles 1 and 5, respectively, and we found a nonlinear association between the EDI and the EMH. The EDI accounted for a substantial part of the general contextual effect on the EMH. The association between the EDI and the EMH was time dependent in stomach and pancreas cancers in men and in cervix cancer.

CONCLUSION

The methodological guidelines proved efficient in describing the way socioeconomic inequalities influence cancer survival. Their use would allow comparisons between different health care systems.

The impact of geographic unit of analysis on socioeconomic inequalities in cancer survival and distant summary stage - a population-based study

OBJECTIVE

When using area-level disadvantage measures, size of geographic unit can have major effects on recorded socioeconomic cancer disparities. This study examined the extent of changes in recorded socioeconomic inequalities in cancer survival and distant stage when the measure of socioeconomic disadvantage was based on smaller Census Collection Districts (CDs) instead of Statistical Local Areas (SLAs).

METHODS

Population-based New South Wales Cancer Registry data were used to identify cases diagnosed with primary invasive cancer in 2000-2008 (n=264,236). Logistic regression and competing risk regression modelling were performed to examine socioeconomic differences in odds of distant stage and hazard of cancer death for all sites combined and separately for breast, prostate, colorectal and lung cancers.

RESULTS

For all sites collectively, associations between socioeconomic disadvantage and cancer survival and distant stage were stronger when the CD-based socioeconomic disadvantage measure was used compared with the SLA-based measure. The CD-based measure showed a more consistent socioeconomic gradient with a linear upward trend of risk of cancer death/distant stage with increasing socioeconomic disadvantage. Site-specific analyses provided similar findings for the risk of death but less consistent results for the likelihood of distant stage.

CONCLUSIONS

The use of socioeconomic disadvantage measure based on the smallest available spatial unit should be encouraged in the future. Implications for public health: Disadvantage measures based on small spatial units can more accurately identify socioeconomic cancer disparities to inform priority settings in service planning.

RELATIVE EFFECTIVENESS IN BREAST CANCER TREATMENT: A HEALTH PRODUCTION APPROACH

Background: Pharmaceuticals’ relative effectiveness has come to the fore in the policy arena, reflecting the need to understand how relative efficacy (what can work) translates into added benefit in routine clinical use (what does work). European payers and licensing authorities assess value for money and post-launch benefit–risk profiles, and efforts to standardize assessments of relative effectiveness across the European Union (EU) are under way. However, the ways that relative effectiveness differs across EU healthcare settings are poorly understood.

Methods: To understand which factors influence differences in relative effectiveness, we developed an analytical framework that treats the healthcare system as a health production function. Using evidence on breast cancer from England, Spain, and Sweden as a case study, we investigated the reasons why the relative effectiveness of a new drug might vary across healthcare systems. Evidence was identified from a literature review and national clinical guidance.

Results: The review included thirteen international studies and thirty country-specific studies. Cross-country differences in population age structure, deprivation, and educational attainment were consistently associated with variation in outcomes. Screening intensity appeared to drive differences in survival, although the impact on mortality was unclear.

Conclusions: The way efficacy translates into relative effectiveness across health systems is likely to be influenced by a range of complex and interrelated factors. These factors could inform government and payer policy decisions on ways to optimize relative effectiveness, and help increase understanding of the potential transferability of data on relative effectiveness from one health system to another.

Socioeconomic inequalities in prostate cancer survival: A review of the evidence and explanatory factors

Although survival rates after prostate cancer diagnosis have improved in the past two decades, survival analyses regarding the socioeconomic status (SES) suggest inequalities indicating worse prognosis for lower SES groups. An overview of the current literature is lacking and moreover, there is an ongoing discussion about the underlying causes but evidence is comparatively sparse. Several patient, disease and health care related factors are discussed to have an important impact on disparities in survival. Therefore, a systematic review was conducted to sum up the current evidence of survival inequalities and the contribution of different potential explanatory factors among prostate cancer patients. The PubMed database was screened for relevant articles published between January 2005 and September 2014 revealing 330 potentially eligible publications. After systematic review process, 46 papers met the inclusion criteria and were included in the review. About 75% of the studies indicate a significant association between low SES and worse survival among prostate cancer patients in the fully adjusted model. Overall, hazard ratios (low versus high SES) range from 1.02 to 3.57. A decrease of inequalities over the years was not identified. 8 studies examined the impact of explanatory factors on the association between SES and survival by progressive adjustment indicating mediating effects of comorbidity, stage at diagnosis and treatment modalities. Eventually, an apparent majority of the obtained studies indicates lower survival among patients with lower SES. The few studies that intend to explain inequalities found out instructive results regarding different contributing factors but evidence is still insufficient.

Neighborhood-level socioeconomic determinants impact outcomes in nonsmall cell lung cancer patients in the Southeastern United States

BACKGROUND

Studies examining the impact of lower socioeconomic status (SES) on the outcomes of patients with nonsmall cell lung cancer (NSCLC) are inconsistent. The objective of this study was to clearly elucidate the association between SES, education, and clinical outcomes among patients with NSCLC.

METHODS

The study population was derived from a consecutive, retrospective cohort of patients with NSCLC who received treatment within the Duke Health System between 1995 and 2007. SES determinants were based on the individual's census tract and corresponding 2000 Census data. Determinants included the percentage of the population living below poverty, the median household income, and the percentages of residents with at least a high school diploma and at least a bachelor's degree. The SES and educational variables were divided into quartiles. Statistical comparisons were performed using the 25th and 75th percentiles.

RESULTS

Individuals who resided in areas with a low median household income or in which a high percentage of residents were living below the poverty line had a shorter cancer-specific 6-year survival than individuals who resided in converse areas (P = .0167 and P = .0067, respectively). Those living in areas in which a higher percentage of residents achieved a high school diploma had improved disease outcomes compared with those living in areas in which a lower percentage attained a high school diploma (P = .0033). A survival advantage also was observed for inhabitants of areas in which a higher percentage of residents attained a bachelor's degree (P = .0455).

CONCLUSIONS

Low SES was identified as an independent prognostic factor for poor survival in patients with both early and advanced stage NSCLC. Patients who lived in areas with high poverty levels, low median incomes, and low education levels had worse mortality.

Variation in advanced stage at diagnosis of lung and female breast cancer in an English region 2006-2009

Background:

Understanding variation in stage at diagnosis can inform interventions to improve the timeliness of diagnosis for patients with different cancers and characteristics.

Methods:

We analysed population-based data on 17 836 and 13 286 East of England residents diagnosed with (female) breast and lung cancer during 2006–2009, with stage information on 16 460 (92%) and 10 435 (79%) patients, respectively. Odds ratios (ORs) of advanced stage at diagnosis adjusted for patient and tumour characteristics were derived using logistic regression.

Results:

We present adjusted ORs of diagnosis in stages III/IV compared with diagnosis in stages I/II. For breast cancer, the frequency of advanced stage at diagnosis increased stepwise among old women (ORs: 1.21, 1.46, 1.68 and 1.78 for women aged 70–74, 75–79, 80–84 and ⩾85, respectively, compared with those aged 65–69 , P<0.001). In contrast, for lung cancer advanced stage at diagnosis was less frequent in old patients (ORs: 0.82, 0.74, 0.73 and 0.66, P<0.001). Advanced stage at diagnosis was more frequent in more deprived women with breast cancer (OR: 1.23 for most compared with least deprived, P=0.002), and in men with lung cancer (OR: 1.14, P=0.011). The observed patterns were robust to sensitivity analyses approaches for handling missing stage data under different assumptions.

Conclusion:

Interventions to help improve the timeliness of diagnosis of different cancers should be targeted at specific age groups.

Influence of socioeconomic environment on survival in patients diagnosed with esophageal cancer: a population-based study

The influence of social environment on survival in patients with cancer has been demonstrated in many studies, subjects living in the most deprived areas having a poorer prognosis. Geographic remoteness and limited access to specialized care centers are often associated with socioeconomic deprivation. The aim was to assess the influence of social environment and geographic remoteness on the relative survival of patients diagnosed with esophageal cancer between 1997 and 2004 in the department of Calvados in France. The study population, which was provided by the Calvados digestive cancer registry, included 629 patients. Relative survival was used to estimate the influence of social environment and geographic remoteness on patient survival. Five-year survival rates were 14.1%, 15.1%, 11.8%, 8.8%, and 11.4%, respectively, for patients living in the least to the most deprived areas (P= 0.39). The influence of social environment was significant after adjustment for clinical variables, patients living in the most deprived areas having the worst survival. These discrepancies cannot totally be explained by differences in access to care, cancer extension, or morphology at diagnosis. No association was observed between distance to the nearest cancer center and survival. Social environment appears to induce disparities among patients diagnosed with esophageal cancer, with a worse prognosis for patients living in the most deprived areas.

Comparing cancer mortality and GDP health expenditure in England and Wales with other major developed countries from 1979 to 2006

Background:

Cancer and gross-domestic-product on health expenditure (GDPHE) are critical issues for major developed countries (MDC). Each country's economic input, GDPHE 1980–2005 is contrasted with clinical outputs, cancer mortality rates (CMRs), to compare their efficiency and effectiveness in reducing CMR.

Methods:

World Health Organization's CMR data for baseline years (1979–1981) are compared with 2004–2006 by sex and age. The χ²-tests are used to determine differences between MDC. Efficiency is analysed by calculating a ratio of average GDPHE to reduced CMR over the period.

Results:

Inputs: All the countries GDPHE grew substantially. For the United Kingdom this reached 9.3%, which is below the MDC average (10%). Outputs: CMR fell substantially (>20%) in six of the ten countries. The male average (15–74 years) CMR in England and Wales had been third highest but by 2004–2006 was sixth, a 31% reduction, which was significantly greater than seven other countries. Initially England and Wales female average CMR was the highest of all countries and is now the second highest. There were significantly greater reductions for the 55–64 and 65–74 years old than in seven and four countries, respectively. GDPHE reduced CMR ratios – the average GDPHE:reduced CMR ratio of England and Wales was 1 : 120, greater than all MDC and double that in four countries.

Conclusion:

Comparing GDPHE input with CMR output showed that relatively the NHS achieved more with proportionately less than other MDC.

Childhood cancer survival in Ireland: temporal, regional and deprivation-related patterns

Survival after childhood cancer varies across Europe, but national or regional studies have so far shown no survival differences related to socio-economic disparity. The relationship of childhood cancer survival to disparity has not been studied in Ireland. We assessed observed survival for Irish children (ages 0-14 years) diagnosed with cancer during the period 1994-2005, overall (for all cancers included in the 3rd edition of the International Classification of Childhood Cancer) and for three main diagnostic groups - leukaemias, lymphomas, and central nervous system tumours. Comparisons were made between two diagnosis periods (1994-1999 and 2000-2005), between four regions of residence, and between five area-based deprivation categories. Regional patterns of treatment were examined to help assess the impact of centralisation of services. There was only limited evidence of improvements in survival over time. No clear evidence was found of deprivation-related influences on childhood cancer survival in Ireland, overall or for the three main diagnostic groups examined, although a weak trend was apparent for lymphoid leukaemias. Regional variation in survival was likewise not clear-cut, with the possible exception of CNS tumours (significantly higher survival amongst patients resident in the Western region). The absence of clear trends or patterns for regional or deprivation-related variation in survival may reflect a high degree of coordination and uniformity of treatment (and perhaps diagnostic) services, and application of standard treatment protocols nationally.

Neighbourhood family income and adverse birth outcomes among singleton deliveries

OBJECTIVE

to assess the association between neighbourhood family income and adverse birth outcomes.

METHODS

we conducted a retrospective cohort study of 334 231 singleton births during 2004 and 2006 based on the Niday Perinatal Database from Ontario. Median neighbourhood family incomes from the 2001 Canadian census were linked with the Niday Perinatal Database by dissemination areas. Generalized estimating equations were applied to estimate the odds ratios of adverse birth outcomes associated with lower neighbourhood income, with adjustment for maternal confounding variables at the individual level.

RESULTS

compared with the highest neighbourhood income quintile, mothers from the lowest quintile were at increased risk of having small for gestational age neonates (OR 1.51; 95% CI 1.46 to 1.57), low birth weight (OR 1.43; 95% CI 1.36 to 1.50), preterm birth (OR 1.17; 95% CI 1.12 to 1.23), low Apgar score (< 7) at five minutes (OR 1.32; 95% CI 1.21 to 1.44), and stillbirth (OR 1.39; 95% CI 1.19 to 1.62). The risks of women from the lowest income quintiles delivering a macrosomic baby (OR 0.81; 95% CI 0.79 to 0.84) or a large for gestational age baby (OR 0.82; 95% CI 0.80 to 0.85) were significantly decreased. No difference in risk of congenital anomaly was found among different income quintiles.

CONCLUSION

a lower level of neighbourhood income is associated with increased risks of small for gestational age babies, low birth weight, preterm birth, low Apgar score at five minutes, and stillbirth.

Socioeconomic status and gastric cancer survival in Japan

BACKGROUND

Few studies have investigated the association between socioeconomic status and the survival of cancer patients in Japan.

METHODS

We examined whether occupation or educational level was associated with the survival of 725 gastric cancer patients who were diagnosed within an ongoing large population-based cohort study.

RESULTS

After adjustment for age at diagnosis, and sex, we found that, compared with professionals or office workers, unemployed subjects (hazard ratio [HR], 2.23; 95% confidence interval [CI], 1.27-3.92) and manual laborers (HR, 1.68; 95% CI, 1.07-2.62) had an increased risk of gastric cancer death. After further adjustment for the clinical extent of disease, the increased risk disappeared. Educational level was not associated with the risk.

CONCLUSIONS

These findings suggest that a disparity in survival by occupation exists among Japanese gastric cancer patients, largely due to a lower proportion of early disease among the unemployed and manual laborers.

Population based time trends and socioeconomic variation in use of radiotherapy and radical surgery for prostate cancer in a UK region: continuous survey

OBJECTIVE

To examine variation in the management of prostate cancer in patients with different socioeconomic status.

DESIGN

Survey using UK regional cancer registry data.

SETTING

Regional population based cancer registry.

PARTICIPANTS

35 171 patients aged >or=51 with a diagnosis of prostate cancer, 1995-2006.

MAIN OUTCOME MEASURES

Use of radiotherapy and radical surgery. Socioeconomic status according to fifths of small area deprivation index.

RESULTS

Over the nine years of the study, information on stage at diagnosis was available for 15 916 of 27 970 patients (57%). During the study period, the proportion of patients treated with radiotherapy remained at about 25%, while use of radical surgery increased significantly (from 2.9% (212/7201) during 1995-7 to 8.4% (854/10 211) during 2004-6, P<0.001). Both treatments were more commonly used in least deprived compared with most deprived patients (28.5% v 21.0% for radiotherapy and 8.4% v 4.0% for surgery). In multivariable analysis, increasing deprivation remained strongly associated with lower odds of radiotherapy or surgery (odds ratio 0.92 (95% confidence interval 0.90 to 0.94), P<0.001, and 0.91 (0.87 to 0.94), P<0.001, respectively, per incremental deprivation group). There were consistently concordant findings with multilevel models for clustering of observations by hospital of diagnosis, with restriction of the analysis to patients with information on stage, and with sequential restriction of the analysis to different age, stage, diagnosis period, and morphology groups.

CONCLUSIONS

After a diagnosis of prostate cancer, men from lower socioeconomic groups were substantially less likely to be treated with radical surgery or radiotherapy. The causes and impact on survival of such differences remain uncertain.

Do patient characteristics, disease, or treatment explain social inequality in survival from colorectal cancer?

This paper investigates the association between individually measured socioeconomic status (SES) and all-cause survival in colorectal cancer patients, and explores whether factors related to the patient, the disease, or the surgical treatment mediate the observed social gradient. The data were derived from a nationwide clinical database of all adenocarcinomas of the colon or rectum diagnosed in Denmark between 2001 and 2004 (inclusive). These data were linked to those from several central registries providing information on income, education, and housing status, as well as to data on comorbidity from previous hospitalizations and use of medication. Only patients with colorectal cancer as their first primary tumour and those born after 1920 were included. A total of 8763 patients were included in the study. Cox proportional hazard regression models revealed a positive social gradient in survival for increasing levels of education and income, and in owners versus renters of housing. A series of regression analyses were used to test potential mediators of the association between the socioeconomic indicators and survival by stepwise inclusion of lifestyle factors (smoking, alcohol intake, body mass index), comorbidity, stage of disease, mode of admission, type of operation, specialization of the surgeon, and curative versus palliative resection. A causal diagram guided the analyses. Inclusion of comorbidity, and to a lesser extent lifestyle, reduced the variation associated with SES, while no evidence of a mediating effect was found for disease or surgical treatment factors. This indicates that the difference in survival among colorectal cancer patients from different social groups was probably not caused by unintentional differences in treatment factors related to surgery, and suggests that primary prevention of chronic diseases among the socially deprived might be one way to reduce social differences in prognosis.

Do lifestyle or social factors explain ethnic/racial inequalities in breast cancer survival?

Despite numerous studies documenting ethnic inequalities in breast cancer survival between minority and majority ethnic groups worldwide, reasons for these inequalities remain unclear. The authors performed a systematic review of published literature to identify studies that investigated the explanatory power of smoking, alcohol consumption, body mass index (BMI), and socioeconomic position (SEP) on ethnic inequalities in breast cancer survival. Sixteen studies were included in the review. From 5 studies, the authors found that differences in breast cancer survival between ethnic groups may be in part explained by BMI, but there was little evidence to implicate smoking or alcohol consumption as explanatory factors of this inequality. From 12 studies, the authors found that SEP explains part of the ethnic inequality in all-cause survival but that it was not evident for breast-cancer-specific survival. SEP explains more of the disparities among African-American versus white women in the United States compared with other ethnic comparisons. Furthermore, given social patterning of BMI and other lifestyle habits, it is possible that results for SEP and BMI are measuring the same effect. In this review, the authors make suggestions regarding the role of epidemiology in facilitating further research to better inform the development of effective policies to address ethnic differences in survival.

Socioeconomic differences in cancer survival: the Norwegian Women and Cancer Study

Background

Cancer survival has been observed to be poorer in low socioeconomic groups, but the knowledge about the underlying causal factors is limited. The purpose of this study was to examine how cancer survival varies by socioeconomic status (SES) among women in Norway, and to identify factors that explain this variation. SES was measured by years of education and gross household income, respectively.

Methods

We used data from The Norwegian Women and Cancer Study, a prospective cohort study including 91 814 women who responded to an extensive questionnaire between 1996 and 1998. A total of 3 899 incident cancer cases were diagnosed during follow-up, of whom 1 089 women died, 919 of them from cancer. Cox Proportional Hazards Model was used to calculate relative risks (RR) of mortality and 95% confidence intervals.

Results

We observed an overall negative socioeconomic gradient in cancer survival, which was most evident in the site specific analyses for survival of ovarian cancer by years of education. For colorectal cancer, mortality increased with years of education, but not with income. After adjustment for household size, marital status, disease stage, and smoking status the SES variation in cancer survival became non-significant. We found that the unequal socioeconomic distribution of smoking status prior to diagnosis contributed considerably to the poorer survival in low SES groups.

Conclusion

We found an overall negative socioeconomic gradient in cancer survival when SES is measured as years of education or gross household income. Smoking status prior to diagnosis was an important predictive factor for socioeconomic variation in survival.

Socioeconomic inequalities in cancer survival in New Zealand: the role of extent of disease at diagnosis

We examined socioeconomic inequalities in cancer survival in New Zealand among 132,006 people ages 15 to 99 years who had a cancer registered (1994-2003) and were followed up to 2004. Relative survival rates (RSR) were calculated using deprivation-specific life tables. A census-based measure of socioeconomic position (New Zealand deprivation based on the 1996 census) based on residence at the time of cancer registration was used. All RSRs were age-standardized, and further standardization was used to investigate the effect of extent of disease at diagnosis on survival. Weighted linear regression was used to estimate the deprivation gap (slope index of inequality) between the most and least deprived cases. Socioeconomic inequalities in cancer survival were evident for all of the major cancer sites, with the deprivation gap being particularly high for prostate (-0.15), kidney and uterus (both -0.14), bladder (-0.12), colorectum (-0.10), and brain (+0.10). Accounting for extent of disease explained some of the inequalities in survival from breast and colorectal cancer and melanoma and all of the deprivation gaps in survival of cervical cancer; however, it did not affect RSRs for cancers of the kidney, uterus, and brain. No substantial differences between the total compared with the non-Māori population were found, indicating that the findings were not due to confounding by ethnicity. In summary, socioeconomic disparities in survival were consistent for nearly all cancer sites, persisted in ethnic-specific analyses, and were only partially explained by differential extent of disease at diagnosis. Further investigation of reasons for persisting inequalities is required.

Socio-economic status and overall and cause-specific mortality in Sweden

BACKGROUND

Previous studies have reported discrepancies in cause-specific mortality among groups of individuals with different socio-economic status. However, most of the studies were limited by the specificity of the investigated populations and the broad definitions of the causes of death. The aim of the present population-based study was to explore the dependence of disease specific mortalities on the socio-economic status in Sweden, a country with universal health care. Another aim was to investigate possible gender differences.

METHODS

Using the 2006 update of the Swedish Family-Cancer Database, we identified over 2 million individuals with socio-economic data recorded in the 1960 national census. The association between mortality and socio-economic status was investigated by Cox's proportional hazards models taking into account the age, time period and residential area in both men and women, and additionally parity and age at first birth in women.

RESULTS

We observed significant associations between socio-economic status and mortality due to cardiovascular diseases, respiratory diseases, to cancer and to endocrine, nutritional and metabolic diseases. The influence of socio-economic status on female breast cancer was markedly specific: women with a higher socio-economic status showed increased mortality due to breast cancer.

CONCLUSION

Even in Sweden, a country where health care is universally provided, higher socio-economic status is associated with decreased overall and cause-specific mortalities. Comparison of mortality among female and male socio-economic groups may provide valuable insights into the underlying causes of socio-economic inequalities in length of life.

Socio-economic status and the risk of liver cancer mortality: a prospective study in Korean men

OBJECTIVE

To examine the association between socio-economic status (SES) and liver cancer mortality among Korean men.

STUDY DESIGN

Prospective cohort study

METHODS

Data were acquired from a large, prospective cohort study that included 548,530 civil service workers aged 30-59 years who had undergone health examination in 1998 provided by the Korean National Health Insurance System. Information on lifestyle and demographic characteristics was acquired through self-administered questionnaires. The main outcome event was mortality from liver cancer. Cox proportional hazards model was used to estimate relative risks (RRs) and 95% confidence intervals (95% CIs) after adjusting for age, body mass index, fasting serum glucose, alcohol consumption, smoking and hepatitis B surface antigen (HBsAg) status.

RESULTS

Liver cancer mortality differentials relating to SES were statistically significant and consistent in the fully adjusted model. Compared with the highest SES category, excess risk associated with liver cancer mortality was observed with decreasing SES levels: the RRs in the upper middle, lower middle and low SES categories were 1.35 (95% CI 1.13-1.61), 1.54 (95% CI 1.28-1.86) and 1.72 (95% CI 1.45-2.04), respectively. There was no effect modification by HBsAg status on the association between SES and liver cancer mortality.

CONCLUSIONS

This study demonstrated an inverse association between SES and liver cancer mortality, suggesting that SES is an independent predictor of liver cancer mortality. The policies and interventions regarding prevention of liver cancer need to focus on disadvantaged groups in order to reduce health disparities related to liver cancer.

Socio-economic deprivation and survival of non-Hodgkin lymphoma in Scotland

Socio-economic deprivation is known to be associated with poorer survival from non-Hodgkin lymphoma (NHL) but routine data have not been able to determine whether this can be explained by differences in disease severity at presentation. We examined survival in all patients diagnosed with NHL in Scotland between 1979 and 1996 and between 1994 and 1996 used Scotland and Newcastle Lymphoma Group data, which include detailed clinical staging information. Compared with individuals from the most affluent areas, survival is 10% poorer in intermediate, and 19% poorer in patients living in the most deprived areas. Deprivation is associated with more B symptoms and poorer performance status but not with other indicators of more advanced disease, suggesting that the disease may be more aggressive or immunocompetence poorer among more deprived populations. We also noted improvements in relative survival from NHL over time.

Changes in cancer incidence and mortality in England and Wales and a comparison of cancer deaths in the major developed countries by age and sex 1979-2002 in context of GDP expenditure on health

Background:

The successful treatment of cancer is a major health and political issue for England and Wales and the major developed countries (MDCs). All malignancy deaths by age and sex are analysed to determine how successful the MDCs were in reducing cancer mortality between the end points of 1979–81 and 2000–2, and whether there was any association between each nations ‘gross domestic product expenditure on health’ (GDPEH) and the reduction in their cancer deaths.

Method:

Incidence of cancer in England and Wales was examined for 1979–80 to 2003–4 to highlight the extent of the problem. The cancer mortality rates for England and Wales were compared with each MDC by age and sex, using ‘WHO all malignancies mortality rates’ for the periods of 1979–81 and 2000–2, and tests of significance were made. The GDPEH for each MDC was examined for 1980–2002, and Spearman rank-order correlations calculated to explore any association between declining cancer deaths and the GDPEH of each MDC.

Results:

Conclusions:

The rising incidence in cancer-related deaths poses a problem for every MDC, and the poorer women’s results should be a matter of concern for most MDCs. The reduction in cancer deaths reflects well on frontline services, and the significant association between reduced cancer mortality and increased GDPEH is encouraging, but still a challenge for governments, especially if the incidence continues to rise.

Social inequality and incidence of and survival from cancers of the kidney and urinary bladder in a population-based study in Denmark, 1994-2003

We investigated the effects of socioeconomic, demographic and health-related indicators on the incidence of and survival from cancers of the kidney and urinary bladder diagnosed in Denmark during 1994-2003 with follow-up through 2006 using information from nationwide registers. The analyses were based on data on 2941 patients with kidney cancer and 9471 patients with urinary bladder cancer in a cohort of 3.22 million people born between 1925 and 1973 and aged >or=30 years. Our results indicate that lower socioeconomic position is associated with higher incidences of cancers at both sites in both sexes, whether socioeconomic position is measured as educational level, disposable income, affiliation to the work market, housing tenure or size of dwelling. We also found a moderate pattern of better survival from cancers at both sites in the most advantaged groups, most clearly reflected by the level of education, disposable income and affiliation to the work market.