Socio-economic inequalities in stage at diagnosis, and in time intervals on the lung cancer pathway from first symptom to treatment: systematic review and meta-analysis

Socio-demographic inequalities in stage at diagnosis of lung cancer: A French population-based study

BACKGROUND

Diagnosing patients at a non-advanced stage has become a mainstay of lung cancer prevention and control strategies. Understanding socio-demographic inequalities in stage at diagnosis may improve the targeting of interventions on patients at higher risk. This study aimed to identify these socio-demographic determinants in a large-scale French population-based cancer registry.

METHODS

All incident lung cancers diagnosed between 2008 and 2019 identified from the Poitou-Charentes Cancer Registry (south-west France) were included. Stage at diagnosis was categorised as advanced/non-advanced (TNM III/IV vs I/II) according to the 8th TNM edition, the objective being to ensure a consistent level of prognosis over time. Socio-demographic variables included age, sex, the French European Deprivation Index (EDI) and patient's place of residence. Their impact on stage at diagnosis was quantified by multivariate logistic regression models with subgroup analyses by histological subtype.

RESULTS

Out of the 15,487 included patients, 75% were diagnosed at an advanced stage (66% to 95% depending on the histological subtype), 17% at a non-advanced stage and 10% at a non-specified stage. Multivariate analysis showed different patterns according to histological subtypes. In patients with adenocarcinoma, a higher risk of advanced stage was found for younger and older patients (u-shape), those most deprived, and those living in rural areas. The same effect of age was reported for squamous cell carcinomas, while no association was found for small-cell lung carcinomas.

CONCLUSIONS

This study highlighted substantial socio-demographic inequalities in stage at diagnosis, specifically for adenocarcinoma patients. Diagnosis strategies could be refined and strengthened in the non-smoker population, in which adenocarcinomas are mainly reported.

Smoking, Lung Cancer Stage, and Prognostic Factors-Findings from the National Lung Screening Trial

BACKGROUND

Low-dose computed tomography (LDCT) increases the early detection of lung cancer. Identifying modifiable behaviors that may affect tumor progression in LDCT-detected patients increases the likelihood of long-term survival and a good quality of life.

METHODS

We examined cigarette smoking behaviors on lung cancer stage, progression, and survival in 299 ever-smoking patients with low-dose CT-detected tumors from the National Lung Screening Trial. Univariate and multivariate Cox models were used to estimate the hazard ratio (HR) for smoking variables on survival time.

RESULTS

Current vs. former smokers and early morning smokers (≤5 min after waking, i.e., time to first cigarette (TTFC) ≤ 5 min) had more advanced-stage lung cancer. The adjusted HR for current vs. former smokers was 1.3 (95% confidence interval [CI] 0.911-1.98, p = 0.136) for overall survival (OS) and 1.3 (0.893-1.87, p = 0.1736) for progression-free survival (PFS). The univariate hazard ratios for TTFC ≤ 5 min vs. >5 min were 1.56 (1.1-2.2, p = 0.013) for OS and 1.53 (1.1-2.12, p = 0.01) for PFS. Among current smokers, the corresponding HRs for early TTFC were 1.78 (1.16-2.74, p = 0.0088) and 1.95 (1.29-2.95, p = 0.0016) for OS and PFS, respectively. In causal mediation analysis, the TTFC effect on survival time was mediated entirely through lung cancer stage.

CONCLUSION

The current findings indicate smoking behaviors at diagnosis may affect lung cancer stage and prognosis.

Machine Learning Techniques to Predict Timeliness of Care among Lung Cancer Patients

Delays in the assessment, management, and treatment of lung cancer patients may adversely impact prognosis and survival. This study is the first to use machine learning techniques to predict the quality and timeliness of care among lung cancer patients, utilising data from the Victorian Lung Cancer Registry (VLCR) between 2011 and 2022, in Victoria, Australia. Predictor variables included demographic, clinical, hospital, and geographical socio-economic indices. Machine learning methods such as random forests, k-nearest neighbour, neural networks, and support vector machines were implemented and evaluated using 20% out-of-sample cross validations via the area under the curve (AUC). Optimal model parameters were selected based on 10-fold cross validation. There were 11,602 patients included in the analysis. Evaluated quality indicators included, primarily, overall proportion achieving "time from referral date to diagnosis date ≤ 28 days" and proportion achieving "time from diagnosis date to first treatment date (any intent) ≤ 14 days". Results showed that the support vector machine learning methods performed well, followed by nearest neighbour, based on out-of-sample AUCs of 0.89 (in-sample = 0.99) and 0.85 (in-sample = 0.99) for the first indicator, respectively. These models can be implemented in the registry databases to help healthcare workers identify patients who may not meet these indicators prospectively and enable timely interventions.

Factors associated with late-stage diagnosis and overall survival for lung cancer: An analysis of patients treated in a Brazilian hospital and a US-hospital from 2009 to 2019

BACKGROUND

Lung cancer is a major public health problem due to its high incidence and mortality rates worldwide. Histology, socioeconomic conditions, access, quality of healthcare, and regional aspects are associated with lung cancer stages at diagnosis and survival outcomes. This paper aims to examine and contrast the factors associated with late-stage diagnosis of lung cancer and overall survival rates in two different settings: a Brazilian hospital and a US hospital, spanning from 2009 to 2019.

METHODS

This is a retrospective cohort study of the incidence of lung cancer cases at the institution's cancer registry from a Brazilian and a US-based cohort. Descriptive analyses are presented using either the mean and standard deviation or the median and interquartile interval. Frequency is used to present categorical variables. Factors associated with late-stage lung cancer diagnosis were identified through bivariate and multivariable forward stepwise logistic regression. One-year overall survival and its associated factors were identified by Kaplan-Meier curves and Cox's proportional hazards model.

RESULTS

Between January 2009 and December 2019, a total of 5286 individuals were diagnosed with LC in the Brazilian cohort, and out of these cases, 85.6% were diagnosed with late-stage disease. The US-cohort consisted of 3594 individuals, of whom 60.3% were diagnosed with late-stage disease in lung cancer. The one-year overall survival was 8.6 months for the US cohort and 6.4 months for the Brazilian cohort. In both cohorts, late-stage diagnosis emerged as the most significant factor influencing overall survival. However, the factors associated with late-stage diagnosis differed between the US and Brazilian cohorts. In the Brazilian cohort, being male and belonging to black or brown ethnic groups, along with having a lower education level, were linked to late-stage diagnosis. On the other hand, in the US-based cohort, the factors related to late-stage diagnosis were being male, having been diagnosed before 2015, and possessing private insurance coverage.

CONCLUSION

Late-stage diagnosis was associated with the worst survival in both the US and Brazilian cohorts. This study provides valuable information on inequities and barriers to access for lung patients with cancer from upper-middle-income and high-income countries.

Regional disparities in cancer survival in Iran: Insight from a National Surveillance of Cancer Survival in Iran (IRANCANSURV)

BACKGROUND AND OBJECTIVES

We aimed to investigate geographical disparity in cancer survival in 9 provincial population-based cancer registries in Iran from 2015 to 2016.

MATERIAL AND METHOD

In the current study, data from 90,862 adult patients (aged >15 years) diagnosed with cancer were retrieved from 9 population-based cancer registries across Iran. Five-year survival rates were estimated by applying relative survival approaches. We also applied the international cancer survival standard weights for age standardization. Finally, we calculated the excess hazard ratio (EHR) for each province adjusted for age, sex, and cancer sites to estimate the excess hazard ratio of mortality compared to the capital province (Tehran).

RESULTS

The largest gap in survival was observed in more curable cancer types, including melanoma (41.4%), ovary (32.3%), cervix (35.0%), prostate (26.7%), and rectum (21.4%), while the observed geographical disparity in lethal cancers such as lung, brain, stomach, and pancreas was less than 15%. Compared to Tehran, we found the highest excess hazard of death in Western Azerbaijan (EHR=1.60, 95% CI 1.51, 1.65), Kermanshah (EHR=1.52, 95% CI=1.44, 1.61), and Kerman (EHR=1.46, 95% CI=1.38, 1.53). The hazard ratio of death was almost identical in Isfahan (EHR=1.04, 95% CI=1.03, 1.06) and Tehran provinces.

CONCLUSION

Provinces with higher HDI had better survival rates. IRANCANSURV study showed regional disparities in cancer survival in Iran. Cancer patients in provinces with a higher Human Development Index (HDI) had a higher survival rate and lived longer compared to the patients in provinces with medium and low HDI regions.

Beyond glyco-proteomics-Understanding the role of genetics in cancer biomarkers

The development of robust cancer biomarkers is the most effective way to improve overall survival, as early detection and treatment leads to significantly better clinical outcomes. Many of the cancer biomarkers that have been identified and are clinically utilized are glycoproteins, oftentimes a specific glycoform. Aberrant glycosylation is a common theme in cancer, with dysregulated glycosylation driving tumor initiation and metastasis, and abnormal glycosylation can be detection both on the tissue surface and in serum. However, most cancer types are heterogeneous in regard to tumor genomics, and this heterogeneity extends to cancer glycomics. This limits the sensitivity of standalone glycan-based biomarkers, which has slowed their implementation clinically. However, if targeted biomarker development can take into account genomic tumor information, the development of complementary biomarkers that target unique cancer subgroups can be accomplished. This idea suggests the need for algorithm-based cancer biomarkers, which can utilize multiple biomarkers along with relevant demographic information. This concept has already been established in the detection of hepatocellular carcinoma with the GALAD score, and an algorithm-based approach would likely be effective in improving biomarker sensitivity for additional cancer types. In order to increase cancer diagnostic biomarker sensitivity, there must be more targeted biomarker development that considers tumor genomic, proteomic, metabolomic, and clinical data while identifying tumor biomarkers.

Association between socioeconomic status and net survival after primary lung cancer surgery: a tertiary university hospital retrospective observational study in Japan

BACKGROUND

Inequalities in opportunities for primary lung cancer surgery due to socioeconomic status exist. We investigated whether socioeconomic inequalities exist in net survival after curative intent surgery at a tertiary university hospital, in Japan.

METHODS

Data from the hospital-based cancer registry on primary lung cancer patients who received lung resection between 2010 and 2018 were linked to the surgical dataset. An area deprivation index, calculated from small area statistics and ranked into tertiles based on Japan-wide distribution, was linked with the patient's address as a proxy measure for individual socioeconomic status. We estimated net survival of up to 5 years by deprivation tertiles. Socioeconomic inequalities in cancer survival were analyzed using an excess hazard model.

RESULTS

Of the 1039 patient-sample, advanced stage (Stage IIIA+) was more prevalent in the most deprived group (28.1%) than the least deprived group (18.0%). The 5-year net survival rates (95% confidence interval) from the least to the most deprived tertiles were 82.1% (76.2-86.6), 77.6% (70.8-83.0) and 71.4% (62.7-78.4), respectively. The sex- and age-adjusted excess hazard ratio of 5-year death was significantly higher in the most deprived group than the least deprived (excess hazard ratio = 1.64, 95% confidence interval: 1.09-2.47). The hazard ratio reduced toward null after additionally accounting for disease stage, suggesting that the advanced stage may explain the poor prognosis among the deprived group.

CONCLUSION

There was socioeconomic inequality in the net survival of patients who received curative intent surgery for primary lung cancer. The lower socioeconomic status group might be less likely to receive early curative surgery.

Effects of Demographic and Socio-Economic Factors on Investigation Time of Lung Cancer Patients in Denmark: A Retrospective Cohort Study

Background

Lung cancer is one of the most common cancer types worldwide. The significance of the individual socio-economic position on the delay in lung cancer diagnosis has not been properly investigated. The purpose of this nationwide population-based study is to examine the association between position and the length of the primary investigation for lung cancer.

Materials and Methods

This register study was based on all lung cancer patients in Denmark who were diagnosed in 2012 to 2017, in total 28,431 patients. We used a multivariate logistic regression model and multivariate zero-inflated negative binomial model to estimate the effect of education level, family income, difficulty of transport, and cohabitation status on the length of the primary investigation.

Results

We found that the patients' income, difficulty of transport, and cohabitation status were associated with the length of the primary investigation. The chance of carrying out the investigation process within 24 days is higher for patients with a high income (adjusted OR = 0.86 with 95% CI (0.81; 0.91)), lower for patients with troublesome transport (adjusted OR = 0.67 with 95% CI (0.61; 0.72)), and lower for patients living alone (adjusted OR = 0.93 with 95% CI (0.88; 0.99)).

Conclusion

Several socio-economic factors are associated with the length of the primary lung cancer investigation. To ensure that all patients receive the most appropriate health care and to avoid extra investigation time, clinicians may pay extra attention to patients who are less fortunate due to low income, troublesome transport to the hospital, or living alone.

A population-based study on social inequality and barriers to healthcare-seeking with lung cancer symptoms

Healthcare-seeking with lung cancer symptoms is a prerequisite for improving timely diagnosis of lung cancer. In this study we aimed to explore barriers towards contacting the general practitioner (GP) with lung cancer symptoms, and to analyse the impact of social inequality. The study is based on a nationwide survey with 69,060 individuals aged ≥40 years, randomly selected from the Danish population. The survey included information on lung cancer symptoms, GP contacts, barriers to healthcare-seeking and smoking status. Information about socioeconomics was obtained by linkage to Danish Registers. Descriptive statistics and multivariate logistic regression model were used to analyse the data. “Being too busy” and “Being worried about wasting the doctor’s time” were the most frequent barriers to healthcare-seeking with lung cancer symptoms. Individuals out of workforce and individuals who smoked more often reported “Being worried about what the doctor might find” and “Being too embarrassed” about the symptoms. The social inequality in barriers to healthcare-seeking with lung cancer symptoms is noticeable, which emphasises the necessity of focus on vulnerable groups at risk of postponing relevant healthcare-seeking.

Work-Related Factors and Lung Cancer Survival: A Population-Based Study in Switzerland (1990-2014)

While previous Swiss studies have demonstrated differences in lung cancer mortality between occupational groups, no estimates are available on the association of occupation-related factors with lung cancer survival. This study aimed at determining whether occupation or work-related factors after diagnosis affect lung cancer survival. We used cancer registry records to identify lung cancer patients diagnosed between 1990 and 2014 in western Switzerland (n = 5773) matched with the Swiss National Cohort. The effect of occupation, the skill level required for the occupation, and the socio-professional category on 5-year lung cancer survival was assessed using non-parametric and parametric methods, controlling for histological type and tumour stage. We found that the net survival varied across skill levels and that the lowest skill level was associated with worse survival in both men and women. In the parametric models with minimal adjustment, we identified several occupational groups at higher risk of mortality compared to the reference category, particularly among men. After adjustment for histological type of lung cancer and tumour stage at diagnosis, most hazard ratios remained higher than 1, though non-statistically significant. Compared to top managers and self-employed workers, workers in paid employment without specific information on occupation were identified as the most at-risk socio-professional category in nearly all models. As this study was conducted using a relatively small sample and limited set of covariates, further studies are required, taking into account smoking habits and administrated cancer treatments. Information on return to work and working conditions before and after lung cancer diagnosis will also be highly valuable for analysing their effect on net lung cancer survival in large nationwide or international studies. Such studies are essential for informing health and social protection systems, which should guarantee appropriate work conditions for cancer survivors, beneficial for their quality of life and survival.

Association of area-level socioeconomic status and non-small cell lung cancer stage by race/ethnicity and health care-level factors: Analysis of the National Cancer Database

BACKGROUND

This study examined whether the association of socioeconomic status (SES) and non-small cell lung cancer (NSCLC) stage varied by race/ethnicity and health care access measures.

METHODS

This study used data from the 2004-2016 National Cancer Database for patients aged 18-89 years who had been diagnosed with Stage 0-IV NSCLC. Adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were calculated for the associations of area-level SES with an advanced stage at diagnosis via multilevel, multivariable logistic regression. The stage at diagnosis was dichotomized into early (0-II) and advanced (III-IV) stages, and area-level SES was categorized on the basis of the patient's zip code level: (1) the proportion of adults aged ≥25 years without a high school degree and (2) the median household income. The models were stratified by race/ethnicity (non-Hispanic [NH] White, NH Black, Hispanic, Asian, American Indian/Alaskan Native, and Native Hawaiian/Pacific Islander), insurance status (none, government, and private), and health care facility type (community, comprehensive community, academic/research, and integrated network).

RESULTS

The study population included 1,329,972 patients. Although only 17% of the NH White patients were in the lowest income quartile, 50% of the NH Black patients were in this group. Lower area-level education and income were associated with higher odds of an advanced-stage diagnosis (aOR for education, 1.12; 95% CI, 1.10-1.13; aOR for income, 1.13; 95% CI, 1.11-1.14). These associations persisted among NH White, NH Black, Hispanic, and Asian patients; among those with government and private insurance (but not the uninsured); and among those treated at each facility type.

CONCLUSIONS

Area-level income and education are strongly associated with an advanced NSCLC diagnosis regardless of the facility type and among those with government and private insurance.

Prevalence of Cardiovascular Disease in Patients With Potentially Curable Malignancies

Background

Although a common challenge for patients and clinicians, there is little population-level evidence on the prevalence of cardiovascular disease (CVD) in individuals diagnosed with potentially curable cancer.

Objectives

We investigated CVD rates in patients with common potentially curable malignancies and evaluated the associations between patient and disease characteristics and CVD prevalence.

Methods

The study included cancer registry patients diagnosed in England with stage I to III breast cancer, stage I to III colon or rectal cancer, stage I to III prostate cancer, stage I to IIIA non-small-cell lung cancer, stage I to IV diffuse large B-cell lymphoma, and stage I to IV Hodgkin lymphoma from 2013 to 2018. Linked hospital records and national CVD databases were used to identify CVD. The rates of CVD were investigated according to tumor type, and associations between patient and disease characteristics and CVD prevalence were determined.

Results

Among the 634,240 patients included, 102,834 (16.2%) had prior CVD. Men, older patients, and those living in deprived areas had higher CVD rates. Prevalence was highest for non-small-cell lung cancer (36.1%) and lowest for breast cancer (7.7%). After adjustment for age, sex, the income domain of the Index of Multiple Deprivation, and Charlson comorbidity index, CVD remained higher in other tumor types compared to breast cancer patients.

Conclusions

There is a significant overlap between cancer and CVD burden. It is essential to consider CVD when evaluating national and international treatment patterns and cancer outcomes.

Spatial assessment of advanced-stage diagnosis and lung cancer mortality in Brazil

The high incidence and mortality rates make lung cancer a global public health issue. Socioeconomic conditions and the provision of health services may be associated with this reality. This study investigates the spatial distribution of advanced-stage diagnosis and mortality due to lung cancer and its association with the healthcare services supply and demographic and socioeconomic indicators in Brazil. This is an ecological study with 161 Intermediate Regions of Urban Articulation. Mortality data were extracted from the Mortality Information System, and the cases of lung cancer were obtained from the Integrator of Hospital-Based Cancer Registries from 2011 to 2015. Analyses employed Moran’s I, local indicators of spatial association, and the multivariable model. The proportion of advanced-stage diagnosis was 85.28% (95% CI 83.31–87.10) and was positively associated with the aging rate (Moran’s I 0.11; p = 0.02), per capita income (Moran’s I 0.05; p = 0.01) and negatively associated with Gini Index (Moran’s I -0.16; p = 0.01). The mean age-adjusted mortality rates was 12.82 deaths/100,000 inhabitants (SD 5.12). The age-adjusted mortality rates for lung cancer presented a positive and statistically significant spatial association with all demographic, socioeconomic and healthcare services supply indicators, except for the "density of family health teams" (Moran’s I -0.02 p = 0.28). The multivariable model for the mortality rates was constituted by the variables “Density of facilities licensed in oncology”, “Per capita income”, and “Health plan coverage”. The per capita income presented positive association and health plan coverage negative association with age-adjusted mortality rates. Both associations were statistically significant. The variable density of facilities licensed in oncology showed no significant association with age-adjusted mortality rates. There is a high proportion of advanced-stage diagnosis across the Brazilian territory and inequalities in lung cancer mortality, which are correlated with the most developed areas of the country.

Diagnosing pancreatic cancer in general practice: a cross-sectional study on associations between suspicion of cancer, urgent referral and time to diagnosis

OBJECTIVE

This study aimed to investigate the first point of contact in patients diagnosed with pancreatic cancer, and to study factors associated with the GP's suspicion of cancer, Cancer Patient Pathway (CPP) referral and long diagnostic interval.

DESIGN

Cross-sectional study combining register and survey data.

PATIENTS

Patients with incident pancreatic cancer recorded in the Danish National Patient Register (n = 303).

MAIN OUTCOME MEASURES

The patient's first point of symptoms presentation, GP's cancer suspicion, CPP referral and diagnostic interval.

RESULTS

General practice was the first point of contact for 85.5% of the population. At the first consultation, cancer was suspected in 32.7% and 22.9% were referred to a CPP. The GPs were more likely to suspect cancer or serious illness in patients aged >70 years (prevalence rate ratio (PRR) 1.34, 95% CI 1.09-1.66) and among patients with high comorbidity (PRR 1.23, 95% CI 1.04-1.47). A CPP referral was less likely among patients with low education. The median diagnostic interval was 39 days (interquartile range: 15-72). When the GP initially did not suspect cancer, the likelihood of longer diagnostic interval increased.

CONCLUSION

The majority of patients with pancreatic cancer began their diagnostic route in general practice. Diagnosing pancreatic cancer swiftly in general practice was challenging; the GP did often not initially suspect cancer or refer to a CPP and several of the patient characteristics were associated with the GPs initial suspicion of cancer or CPP referral. Thus, there may be room for improvements in the diagnostics of pancreatic cancer in general practice.Key pointsPatients with pancreatic cancer have a poor prognosis, as pancreatic cancer is often diagnosed in late stage.The majority of patients with pancreatic cancer began their diagnostic process in general practice.General practitioners (GPs) suspected cancer at the first consultation in one out of three patients with pancreatic cancer; more often in older and comorbid patients.The GPs suspicion of cancer was associated with urgent referral and shorter time to diagnosis.

Socio-Economic Inequalities in Lung Cancer Outcomes: An Overview of Systematic Reviews

In the past decade, evidence has accumulated about socio-economic inequalities in very diverse lung cancer outcomes. To better understand the global effects of socio-economic factors in lung cancer, we conducted an overview of systematic reviews. Four databases were searched for systematic reviews reporting on the relationship between measures of socio-economic status (SES) (individual or area-based) and diverse lung cancer outcomes, including epidemiological indicators and diagnosis- and treatment-related variables. AMSTAR-2 was used to assess the quality of the selected systematic reviews. Eight systematic reviews based on 220 original studies and 8 different indicators were identified. Compared to people with a high SES, people with a lower SES appear to be more likely to develop and die from lung cancer. People with lower SES also have lower cancer survival, most likely due to the lower likelihood of receiving both traditional and next-generation treatments, higher rates of comorbidities, and the higher likelihood of being admitted as emergency. People with a lower SES are generally not diagnosed at later stages, but this may change after broader implementation of lung cancer screening, as early evidence suggests that there may be socio-economic inequalities in its use.

Health-Related and Behavioral Factors Associated With Lung Cancer Stage at Diagnosis: Observations From Alberta's Tomorrow Project

Background

Lung cancer is the leading cause of cancer death in Canada, with stage at diagnosis among the top predictors of lung cancer survival. Identifying factors associated with stage at diagnosis can help reduce lung cancer morbidity and mortality. This study used data from a prospective cohort study of adults living in Alberta, Canada to examine factors associated with lung cancer stage at diagnosis.

Methods

This cohort study used data from adults aged 35–69 years enrolled in Alberta’s Tomorrow Project. Partial Proportional Odds models were used to examine associations between sociodemographic characteristics and health-related factors and subsequent lung cancer stage at diagnosis.

Results

A total of 221 participants (88 males and 133 females) developed lung cancer over the study period. Nearly half (48.0%) of lung cancers were diagnosed at a late stage (stage IV), whereas 30.8 % and 21.3% were diagnosed at stage I/II and III, respectively. History of sunburn in the past year was protective against late-stage lung cancer diagnosis (odds ratio (OR) .40, P=.005). In males, a higher number of lifetime prostate specific antigen tests was associated with reduced odds of late-stage lung cancer diagnosis (odds ratio .66, P=.02). Total recreational physical activity was associated with increased odds of late-stage lung cancer diagnosis (OR 1.08, P=.01).

Discussion

Lung cancer stage at diagnosis remains a crucial determinant of prognosis. This study identified important factors associated with lung cancer stage at diagnosis. Study findings can inform targeted cancer prevention initiatives towards improving early detection of lung cancer and lung cancer survival.

The impact of social determinants of health on management of stage I non-small cell lung cancer

BACKGROUND

Social Determinants of Health (SDOH) can be important contributors in health care outcomes. We hypothesized that certain SDOH independently impact the management and outcomes of stage I Non-Small Cell Lung Cancer (NSCLC).

STUDY DESIGN

Patients with clinical stage I NSCLC were identified from the National Cancer Database. The impact of SDOH factors on utilization of surgery, perioperative outcomes and overall survival were examined, both in bivariate and multivariable analyses.

RESULTS

A total of 236,140 patients were identified. In multivariate analysis, SDOH marginalization were associated with less frequent use of surgery, lower 5-year survival and, in surgical patients, more frequent use of open surgery and lower 90-day postoperative survival.

CONCLUSION

SDOH disparities have a significant impact in the management and outcomes of stage I NSCLC. We identified SDOH patient groups particularly impacted by such disparities, in which higher utilization of surgery and minimally invasive approaches may lead to improved outcomes.

Socioeconomic Disparities in Non-Small Cell Lung Cancer With Brain Metastases at Presentation: A Population-Based Study

OBJECTIVE/BACKGROUND

The purpose of this study was to characterize the impact of household income disparities in the survival of patients with non-small cell lung cancer (NSCLC) presenting with brain metastasis on a population-based level.

METHODS

This is a population-based cohort study using the Surveillance, Epidemiology, and End Results (SEER) database from 2010-2016 including 15,808 NSCLC patients presenting with brain metastasis.

RESULTS

This study comprises 15,808 adult patients with NSCLC presenting with brain metastases having an age range 64 ± 10 years with 51% male, 76% white, 52% married, 61% insured, and with 85% of lung adenocarcinoma histopathology. The 1-, 2- and 5-year survival rates for living in the lower household income quartile were 21%, 10%, and 3%, respectively, for the second quartile 24%, 10%, and 3%; for the third quartile 28%, 14%, and 4%; and for the top quartile 31%, 17%, and 4%, respectively. Multivariate Cox proportional hazard analysis showed that living in a higher quartile household income county is associated with increased survival (P < 0.0001), hazard ratio 0.87, 95% confidence interval (0.82-0.92).

CONCLUSIONS

This population-based study suggests that living in higher median household income counties is associated with increased survival time and reduced risk of mortality for patients with NSCLC who have brain metastases present at diagnosis, independent of other factors. These findings underscore the importance of ensuring adequate and easy access to care for all patients, irrespective of their economic background.

Reducing health inequalities through general practice: protocol for a realist review (EQUALISE)

INTRODUCTION

Healthcare organisations recognise the moral imperative to address inequalities in health outcomes but often lack an understanding of which types of interventions are likely to reduce them. This realist review will examine the existing evidence on the types of interventions or aspects of routine care in general practice that are likely to decrease or increase health inequalities (ie, inequality-generating interventions) across cardiovascular disease, cancer, diabetes and chronic obstructive pulmonary disease.

METHODS AND ANALYSIS

Our realist review will follow Pawson's five iterative stages. We will start by developing an initial programme theory based on existing theories and discussions with stakeholders. To navigate the large volume of literature, we will access the primary studies through the identification of published systematic reviews of interventions delivered in general practice across the four key conditions. We will examine the primary studies included within each systematic review to identify those reporting on inequalities across PROGRESS-Plus categories. We will collect data on a range of clinical outcomes including prevention, diagnosis, follow-up and treatment. The data will be synthesised using a realist logic of analysis. The findings will be a description and explanation of the general practice interventions which are likely to increase or decrease inequalities across the major conditions.

ETHICS AND DISSEMINATION

Ethics approval is not required because this study does not include any primary research. The findings will be integrated into a series of guiding principles and a toolkit for healthcare organisations to reduce health inequalities. Findings will be disseminated through peer-reviewed publications, conference presentations and user-friendly summaries.

PROSPERO REGISTRATION NUMBER

CRD42020217871.

Cancer care reform in South Africa: A case for cancer care coordination: A narrative review

OBJECTIVE

This review provides an overview of the existing literature on the importance of care coordination for lung cancer care and other cancers in general. The review is inclusive of the burden of cancer, with a special reference to lung cancer, as well as challenges and achievements relating to cancer care coordination.

METHOD

We conducted a search of online databases of peer-reviewed studies published in the English language. The analysis for this review has been packaged into themes in order to generate results that can inform researchers and cancer health professionals, on the existing gaps necessary for developing appropriate intervention strategies and policy guidelines.

RESULTS

Cancer is a complex condition that often requires multiple interventions provided by a variety of health professionals within the healthcare continuum. This paper reviewed research studies that explored the supportive care needs of cancer patients. The results are presented in three superordinate themes, namely (a) cancer as a healthcare priority in South Africa (SA), (b) making a case for coordinated cancer care in SA, and (c) care coordination: a poorly defined, yet complex concept. One major need identified was the requirement of informational support. Other essential needs included referral, emotional, and financial support.

SIGNIFICANCE OF RESULTS

The identification of current obstacles has the potential to guide the development of a model to improve quality coordinated cancer health care. It remains that limited research exists around cancer services and cancer care in the South African region. This narrative review identified common elements and barriers to care for lung cancer patients and survivors, and offers recommendations for developing clinical care models.

Socio-demographic variation in stage at diagnosis of breast, bladder, colon, endometrial, lung, melanoma, prostate, rectal, renal and ovarian cancer in England and its population impact

BACKGROUND

Stage at diagnosis strongly predicts cancer survival and understanding related inequalities could guide interventions.

METHODS

We analysed incident cases diagnosed with 10 solid tumours included in the UK government target of 75% of patients diagnosed in TNM stage I/II by 2028. We examined socio-demographic differences in diagnosis at stage III/IV vs. I/II. Multiple imputation was used for missing stage at diagnosis (9% of tumours).

RESULTS

Of the 202,001 cases, 57% were diagnosed in stage I/II (an absolute 18% 'gap' from the 75% target). The likelihood of diagnosis at stage III/IV increased in older age, though variably by cancer site, being strongest for prostate and endometrial cancer. Increasing level of deprivation was associated with advanced stage at diagnosis for all sites except lung and renal cancer. There were, inconsistent in direction, sex inequalities for four cancers. Eliminating socio-demographic inequalities would translate to 61% of patients with the 10 studied cancers being diagnosed at stage I/II, reducing the gap from target to 14%.

CONCLUSIONS

Potential elimination of socio-demographic inequalities in stage at diagnosis would make a substantial, though partial, contribution to achieving stage shift targets. Earlier diagnosis strategies should additionally focus on the whole population and not only the high-risk socio-demographic groups.

Socio-Economic Position, Cancer Incidence and Stage at Diagnosis: A Nationwide Cohort Study in Belgium

Background: Socio-economic position is associated with cancer incidence, but the direction and magnitude of this relationship differs across cancer types, geographical regions, and socio-economic parameters. In this nationwide cohort study, we evaluated the association between different individual-level socio-economic and -demographic factors, cancer incidence, and stage at diagnosis in Belgium. Methods: The 2001 census was linked to the nationwide Belgian Cancer Registry for cancer diagnoses between 2004 and 2013. Socio-economic parameters included education level, household composition, and housing conditions. Incidence rate ratios were assessed through Poisson regression models. Stage-specific analyses were conducted through logistic regression models. Results: Deprived groups showed higher risks for lung cancer and head and neck cancers, whereas an inverse relation was observed for malignant melanoma and female breast cancer. Typically, associations were more pronounced in men than in women. A lower socio-economic position was associated with reduced chances of being diagnosed with known or early stage at diagnosis; the strongest disparities were found for male lung cancer and female breast cancer. Conclusions: This study identified population groups at increased risk of cancer and unknown or advanced stage at diagnosis in Belgium. Further investigation is needed to build a comprehensive picture of socio-economic inequality in cancer incidence.

Time from presentation to pre-diagnostic chest X-ray in patients with symptomatic lung cancer: a cohort study using electronic patient records from English primary care

BACKGROUND

National guidelines in England recommend prompt chest X-ray (within 14 days) in patients presenting in general practice with unexplained symptoms of possible lung cancer, including persistent cough, shortness of breath, or weight loss.

AIM

To examine time to chest X-ray in symptomatic patients in English general practice before lung cancer diagnosis, and explore demographical variation.

DESIGN AND SETTING

Retrospective cohort study using routinely collected general practice, cancer registry, and imaging data from England.

METHOD

Patients with lung cancer who presented symptomatically in general practice in the year pre-diagnosis and who had a pre-diagnostic chest X-ray were included. Time from presentation to chest X-ray (presentation-test interval) was determined and intervals classified based on national guideline recommendations as concordant (≤14 days) or non-concordant (>14 days). Variation in intervals was examined by age, sex, smoking status, and deprivation.

RESULTS

In a cohort of 2102 patients with lung cancer, the median presentation-test interval was 49 (interquartile range [IQR] 5-172) days. Of these, 727 (35%) patients had presentation-test intervals of ≤14 days (median 1 [IQR 0-6] day) and 1375 (65%) had presentation-test intervals of >14 days (median 128 [IQR 52-231] days). Intervals were longer among patients who smoke (equivalent to 63% longer than non-smokers; P<0.001), older patients (equivalent to 7% longer for every 10 years from age 27; P = 0.013), and females (equivalent to 12% longer than males; P = 0.016).

CONCLUSION

In symptomatic primary care patients who underwent chest X-ray before lung cancer diagnosis, only 35% were tested within the timeframe recommended by national guidelines. Patients who smoke, older patients, and females experienced longer intervals. These findings could help guide initiatives aimed at improving timely lung cancer diagnosis.

The Use of Bronchoscopy During the Coronavirus Disease 2019 Pandemic: CHEST/AABIP Guideline and Expert Panel Report

BACKGROUND

The coronavirus disease 2019 (COVID-19) has swept the globe and is causing significant morbidity and mortality. Given that the virus is transmitted via droplets, open airway procedures such as bronchoscopy pose a significant risk to health-care workers (HCWs). The goal of this guideline was to examine the current evidence on the role of bronchoscopy during the COVID-19 pandemic and the optimal protection of patients and HCWs.

STUDY DESIGN AND METHODS

A group of approved panelists developed key clinical questions by using the Population, Intervention, Comparator, and Outcome (PICO) format that addressed specific topics on bronchoscopy related to COVID-19 infection and transmission. MEDLINE (via PubMed) was systematically searched for relevant literature and references were screened for inclusion. Validated evaluation tools were used to assess the quality of studies and to grade the level of evidence to support each recommendation. When evidence did not exist, suggestions were developed based on consensus using the modified Delphi process.

RESULTS

The systematic review and critical analysis of the literature based on six PICO questions resulted in six statements: one evidence-based graded recommendation and 5 ungraded consensus-based statements.

INTERPRETATION

The evidence on the role of bronchoscopy during the COVID-19 pandemic is sparse. To maximize protection of patients and HCWs, bronchoscopy should be used sparingly in the evaluation and management of patients with suspected or confirmed COVID-19 infections. In an area where community transmission of COVID-19 infection is present, bronchoscopy should be deferred for nonurgent indications, and if necessary to perform, HCWs should wear personal protective equipment while performing the procedure even on asymptomatic patients.

Why do delays to diagnosis and treatment of lung cancer occur? A mixed methods study of insights from Australian clinicians

AIMS

Delays in lung cancer diagnosis and treatment can impact survival. We explored reasons for delays experienced by patients with lung cancer to identify themes and strategies for improvement.

METHODS

We used national timeframe recommendations and standardized definitions to identify General Practitioners and specialists caring for 34 patients who experienced delays in our previous Medicare data linkage study. Clinicians participated in a survey and interview, including qualitative (exploratory, open-ended questions) and quantitative (rating scales) components. Exploratory content analysis, cross-case triangulation, and descriptive statistics were performed. Krippendorff's coefficient was used to assess level of agreement between clinicians and patients, and among clinicians, on perceived delays.

RESULTS

Overall, 27 out of 50 (54%) eligible clinicians participated (including 11 respiratory physicians and seven medical oncologists). Dominant themes for perceived causes of delay included referral barriers, limited General Practitioner (GP) awareness of subtle clinical presentations, insufficient radiology interpretation, and lack of cancer coordinators. "Unavoidable" delays may occur due to clinical circumstances. Awareness and uptake of referral and timeframe guidelines were low, with clinicians using professional networks over guidelines. There was no consistent agreement on perceived delays between patients and clinicians, and among clinicians (Krippendorff's coefficient .03 [P = .8]).

CONCLUSIONS

Strategies for minimizing avoidable delays include efficient GP to specialist referral and more lung cancer coordinators to assist with patient expectations and waitlist management. Clinicians' reliance on experience, rather than guidelines, indicates need to review guideline utility. Raising awareness of benchmarks and unavoidable barriers may recalibrate perceptions of "delays" to diagnosis and treatment of lung cancer.

Comorbidity prevalence among cancer patients: a population-based cohort study of four cancers

BACKGROUND

The presence of comorbidity affects the care of cancer patients, many of whom are living with multiple comorbidities. The prevalence of cancer comorbidity, beyond summary metrics, is not well known. This study aims to estimate the prevalence of comorbid conditions among cancer patients in England, and describe the association between cancer comorbidity and socio-economic position, using population-based electronic health records.

METHODS

We linked England cancer registry records of patients diagnosed with cancer of the colon, rectum, lung or Hodgkin lymphoma between 2009 and 2013, with hospital admissions records. A comorbidity was any one of fourteen specific conditions, diagnosed during hospital admission up to 6 years prior to cancer diagnosis. We calculated the crude and age-sex adjusted prevalence of each condition, the frequency of multiple comorbidity combinations, and used logistic regression and multinomial logistic regression to estimate the adjusted odds of having each condition and the probability of having each condition as a single or one of multiple comorbidities, respectively, by cancer type.

RESULTS

Comorbidity was most prevalent in patients with lung cancer and least prevalent in Hodgkin lymphoma patients. Up to two-thirds of patients within each of the four cancer patient cohorts we studied had at least one comorbidity, and around half of the comorbid patients had multiple comorbidities. Our study highlighted common comorbid conditions among the cancer patient cohorts. In all four cohorts, the odds of having a comorbidity and the probability of multiple comorbidity were consistently highest in the most deprived cancer patients.

CONCLUSIONS

Cancer healthcare guidelines may need to consider prominent comorbid conditions, particularly to benefit the prognosis of the most deprived patients who carry the greater burden of comorbidity. Insight into patterns of cancer comorbidity may inform further research into the influence of specific comorbidities on socio-economic inequalities in receipt of cancer treatment and in short-term mortality.

The prognostic impact of obstructive lung disease on survival of never smokers with resected non-small-cell lung cancer: a comparison with smokers

OBJECTIVES

The proportion of never smokers among non-small-cell lung cancer (NSCLC) patients has steadily increased in recent decades, suggesting an urgent need to identify the major underlying causes of disease in this cohort. Chronic obstructive pulmonary disease is a risk factor for lung cancer in both smokers and never smokers. The aim of this study was to investigate the association between obstructive lung disease and survival in never smokers and smokers with NSCLC after complete resection.

METHODS

We retrospectively reviewed data from 548 NSCLC patients treated at our institution. The effects of obstructive lung disease on recurrence-free survival and cancer-specific survival following the resection of NSCLC were determined by univariable and multivariable Cox regression analyses.

RESULTS

Among the 548 patients analysed, 244 patients (44.5%) were never smokers and 304 patients (55.4%) were current or former smokers. In the never-smoker group, 48 patients (19.7%) had obstructive lung disease, 185 patients (75.8%) were women and 226 patients (92.6%) had adenocarcinoma. Obstructive lung disease was significantly associated with shorter recurrence-free survival (P = 0.006) and cancer-specific survival (P = 0.022) in the never smokers, but not the smokers, on both univariable and multivariable analyses. The associations between obstructive lung disease and prognosis in never smokers remained significant after propensity score matching.

CONCLUSIONS

Obstructive lung disease is an independent prognostic factor for recurrence-free survival and cancer-specific survival in never smokers, but not in smokers, with NSCLC. Based on this finding, further examination is warranted to advance our understanding of the mechanisms associated with NSCLC in never smokers.

Nationwide cohort study of the impact of education, income and social isolation on survival after acute colorectal cancer surgery

Background

Acute colorectal cancer surgery has been associated with a high postoperative mortality. The primary aim of this study was to examine the association between socioeconomic position and the likelihood of undergoing acute versus elective colorectal cancer surgery. A secondary aim was to determine 1‐year survival among patients treated with acute surgery.

Methods

All patients who had undergone a surgical procedure according to the Danish Colorectal Cancer Group (DCCG.dk) database, or who were registered with stent or diverting stoma in the National Patient Register from 2007 to 2015, were reviewed. Socioeconomic position was determined by highest attained educational level, income, urbanicity and cohabitation status, obtained from administrative registries. Co‐variables included age, sex, year of surgery, Charlson Co‐morbidity Index score, smoking status, alcohol consumption, BMI, stage and tumour localization. Logistic regression analysis was performed to determine the likelihood of acute colorectal cancer surgery, and Kaplan–Meier and Cox proportional hazards regression methods were used for analysis of 1‐year overall survival.

Results

In total, 35 661 patients were included; 5310 (14·9 per cent) had acute surgery. Short and medium education in patients younger than 65 years (odds ratio (OR) 1·58, 95 per cent c.i. 1·32 to 1·91, and OR 1·34, 1·15 to 1·55 respectively), low income (OR 1·12, 1·01 to 1·24) and living alone (OR 1·35, 1·26 to 1·46) were associated with acute surgery. Overall, 40·7 per cent of patients died within 1 year of surgery. Short education (hazard ratio (HR) 1·18, 95 per cent c.i. 1·03 to 1·36), low income (HR 1·16, 1·01 to 1·34) and living alone (HR 1·25, 1·13 to 1·38) were associated with reduced 1‐year survival after acute surgery.

Conclusion

Low socioeconomic position was associated with an increased likelihood of undergoing acute colorectal cancer surgery, and with reduced 1‐year overall survival after acute surgery.

Are social inequalities in acute myeloid leukemia survival explained by differences in treatment utilization? Results from a French longitudinal observational study among older patients

Background

Evidences support social inequalities in cancer survival. Studies on hematological malignancies, and more specifically Acute Myeloid Leukemia (AML), are sparser. Our study assessed: 1/ the influence of patients’ socioeconomic position on survival, 2/ the role of treatment in this relationship, and 3/ the influence of patients’ socioeconomic position on treatment utilization.

Methods

This prospective multicenter study includes all patients aged 60 and older, newly diagnosed with AML, excluding promyelocytic subtypes, between 1st January 2009 to 31st December 2014 in the South-West of France. Data came from medical files. Patients’ socioeconomic position was measured by an ecological deprivation index, the European Deprivation Index. We studied first, patients’ socioeconomic position influence on overall survival (n = 592), second, on the use of intensive chemotherapy (n = 592), and third, on the use of low intensive treatment versus best supportive care among patients judged unfit for intensive chemotherapy (n = 405).

Results

We found an influence of patients’ socioeconomic position on survival (highest versus lowest position HR_Q5: 1.39 [1.05;1.87] that was downsized to become no more significant after adjustment for AML ontogeny (HR_Q5: 1.31[0.97;1.76] and cytogenetic prognosis HR_Q5: 1.30[0.97;1.75]). The treatment was strongly associated with survival. A lower proportion of intensive chemotherapy was observed among patients with lowest socioeconomic position (OR_Q5: 0.41[0.19;0.90]) which did not persist after adjustment for AML ontogeny (OR_Q5: 0.59[0.25;1.40]). No such influence of patients’ socioeconomic position was found on the treatment allocation among patients judged unfit for intensive chemotherapy.

Conclusions

Finally, these results suggest an indirect influence of patients’ socioeconomic position on survival through AML initial presentation.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-6093-3) contains supplementary material, which is available to authorized users.

Age at death and the effect of lead-time bias in patients with colorectal cancer: a 10-year follow-up

AIM

Studies addressing the benefit of early intervention are prone to lead-time bias, which results in an artificial improvement in cancer-specific mortality. We have previously compared the age at death for patients with colorectal cancer presenting on an emergency or elective basis. In this study, we aimed to repeat the analysis with a minimum follow-up of 10 years.

METHOD

A nonscreen-detected cohort of patients presenting with colorectal cancer to three Lanarkshire Hospitals between 2000 and 2006 were entered into a prospective database, with analysis performed on 28 November 2016. The following data were collected: age at death, presentation type (emergency/elective), operative intent (palliative/curative) and Dukes stage. Results are presented as [mean (95% confidence intervals)]. Statistical analysis was undertaken using Student's t-test and multivariate analysis performed using Cox proportional hazard models.

RESULTS

One thousand six hundred and thirty-six patients were identified. Elective patients presented younger than emergency patients [67.9 (67.3-68.5) vs 70.9 (69.6-72.2) years; P < 0.0001]. Overall mortality was 71.1% at time of analysis; no difference was seen in the mean age at death between emergency and elective presentation [73.5 (72.4-74.8) vs 73.6 (72.3-74.9) years; P = 0.841].

CONCLUSION

Current early detection strategies to diagnose colorectal cancer may improve cancer-specific survival by increasing lead-time bias. However, in our cohort of symptomatic patients, treatment on an elective or emergency basis does not influence overall survival. These data suggest that in selected patients, particularly where there is comorbidity, it may be reasonable to adopt a more expectant approach to investigate and treat colorectal symptoms.

Variation in the time to treatment for stage III and IV non-small cell lung cancer patients for hospitals in the Netherlands

OBJECTIVES

Increased emphasis on molecular diagnostics can lead to increased variation in time to treatment (TTT) for patients with stage III and IV non-small cell lung cancer. This article presents the variation in TTT for advanced NSCLC patients observed in Dutch hospitals before the widespread use of immunotherapy. The aim of this article was to explore the variation in TTT between patients, as well as between hospitals.

MATERIAL AND METHODS

Based on the Netherlands Cancer Registry, we used patient-level data (n = 4096) from all 78 hospitals that diagnosed stage III or IV NSCLC in the Netherlands in 2016. To investigate how patient characteristics and hospital-level effects are associated with TTT (from diagnosis until start treatment), we interpreted regression model results for five common patient profiles to analyze the influence of age, gender, tumor stage, performance status, histology, and referral status as well as hospital-level characteristics on the TTT.

RESULTS AND CONCLUSIONS

TTT varies substantially between and within hospitals. The median TTT was 28 days with an inter-quartile range of 22 days. The hospital-level median TTT ranges from 17 to 68 days. TTT correlates significantly with tumor stage, performance status, and histology. The hospital-level effect, unrelated to hospital volume and type, affected TTT by several weeks at most. For most patients, TTT is within range as recommended in current guidelines. Variation in TTT seems higher for patients receiving either radiotherapy or targeted therapy, or for patients referred to another hospital and we hypothesize this is related to the complexity of the diagnostic pathway. With further advances in molecular diagnostics and precision oncology we expect variation in TTT to increase and this needs to be considered in designing optimal cancer care delivery.

Educational level and management and outcomes in non-small cell lung cancer. A nationwide population-based study

OBJECTIVES

We examined associations between educational level and clinical presentation, patterns of management and mortality in patients with non-small cell lung cancer (NSCLC) in Sweden, a country with a National Health Care System.

MATERIALS AND METHODS

We identified 39,671 patients with a NSCLC diagnosis 2002-2016 in Lung Cancer Data Base Sweden (LCBaSe), a population-based research database. In analyses adjusted for comorbidity and other prognostic factors, odds Ratios (OR) and hazard Ratios (HR) were estimated to examine associations between patients' educational level and aspects of management and mortality.

RESULTS

Stage at diagnosis and waiting times did not differ between educational groups. In multivariable analysis, the likelihood to undergo PET/CT and assessment in a multidisciplinary team setting were higher in patients with high compared to low education (aOR 1.14; CI 1.05-1.23 and aOR 1.22; CI 1.14-1.32, respectively). In patients with early stage IA-IIB disease, the likelihood to undergo stereotactic radiotherapy was elevated in patients with high education (aOR 1.40; CI 1.03-1.91). Both all-cause (aHR 0.86; CI 0.77-0.92) and cause-specific mortality (aHR 0.83; CI 0.74-0.92) was lower in patients with high compared to low education in early stage disease (IA-IIB). In higher stage NSCLC no differences were observed. Patterns were similar in separate assessments stratified by sex and histopathology.

CONCLUSIONS

While stage at diagnosis and waiting times did not differ between educational groups, we found socioeconomic differences in diagnostic intensity, multidisciplinary team assessment, stereotactic radiotherapy and mortality in patients with NSCLC. These findings may in part reflect social gradients in implementation and use of novel diagnostic and treatment modalities. Our findings underscore the need for improved adherence to national guidelines.

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.

Development and validation of a search filter to identify equity-focused studies: reducing the number needed to screen

Background

Health inequalities, worse health associated with social and economic disadvantage, are reported by a minority of research articles. Locating these studies when conducting an equity-focused systematic review is challenging due to a deficit in standardised terminology, indexing, and lack of validated search filters. Current reporting guidelines recommend not applying filters, meaning that increased resources are needed at the screening stage.

Methods

We aimed to design and test search filters to locate studies that reported outcomes by a social determinant of health. We developed and expanded a ‘specific terms strategy’ using keywords and subject headings compiled from recent systematic reviews that applied an equity filter. A ‘non-specific strategy’ was compiled from phrases used to describe equity analyses that were reported in titles and abstracts, and related subject headings. Gold standard evaluation and validation sets were compiled. The filters were developed in MEDLINE, adapted for Embase and tested in both. We set a target of 0.90 sensitivity (95% CI; 0.84, 0.94) in retrieving 150 gold standard validation papers. We noted the reduction in the number needed to screen in a proposed equity-focused systematic review and the proportion of equity-focused reviews we assessed in the project that applied an equity filter to their search strategy.

Results

The specific terms strategy filtered out 93-95% of all records, and retrieved a validation set of articles with a sensitivity of 0.84 in MEDLINE (0.77, 0.89), and 0.87 (0.81, 0.92) in Embase. When combined (Boolean ‘OR’) with the non-specific strategy sensitivity was 0.92 (0.86, 0.96) in MEDLINE (Embase 0.94; 0.89, 0.97). The number needed to screen was reduced by 77% by applying the specific terms strategy, and by 59.7% (MEDLINE) and 63.5% (Embase) by applying the combined strategy. Eighty-one per cent of systematic reviews filtered studies by equity.

Conclusions

A combined approach of using specific and non-specific terms is recommended if systematic reviewers wish to filter studies for reporting outcomes by social determinants. Future research should concentrate on the indexing standardisation for equity studies and further development and testing of both specific and non-specific terms for accurate study retrieval.

Electronic supplementary material

The online version of this article (10.1186/s12874-018-0567-x) contains supplementary material, which is available to authorized users.

Effect of socioeconomic status on stage at diagnosis of lung cancer in a hospital-based multicenter retrospective clinical epidemiological study in China, 2005-2014

There is inconsistent evidence of associations between socioeconomic status (SES) and lung cancer stage in non‐Chinese populations up to now. We set out to determine how SES affects stage at diagnosis at both individual and area levels, from a hospital‐based multicenter 10‐year (2005–2014) retrospective clinical epidemiological study of 7184 primary lung cancer patients in mainland China. Individual‐level SES data were measured based on two indicators from case report forms of the study: an individual's education and occupation. Seven census indicator variables were used as surrogates for the area‐level SES with principal component analysis (PCA). Multivariate analysis was undertaken using binary logistic regressions and multinomial logit model to describe the association and explore the effect across tertiles on stage after adjusting for demographic variables. There was a significant stepwise gradient of effect across different stages in the highest tertile of area‐level SES, comparing with the lowest tertile of area‐level SES (ORs, 0.77, 0.67, and 0.29 for stage II, III, and IV). Patients with higher education were less likely to have stage IV lung cancer, comparing with the illiterate group (ORs, 0.52, 0.63, 0.71, 0.64 for primary school, middle school, high school, college degree or above subgroup, respectively). Findings suggest that the most socioeconomically deprived areas may be associated with a higher risk of advanced‐stage lung cancer, and increasing educational level may be correlated with a lower risk to be diagnosed at advanced stage in both men and women.