Explaining the Socioeconomic Variation in Cancer Risk in the Norwegian Women and Cancer Study

Epidemiology of HPV-associated cancers past, present and future: towards prevention and elimination

Cervical cancer is the first cancer deemed amenable to elimination through prevention, and thus lessons from the epidemiology and prevention of this cancer type can provide information on strategies to manage other cancers. Infection with the human papillomavirus (HPV) causes virtually all cervical cancers, and an important proportion of oropharyngeal, anal and genital cancers. Whereas 20th century prevention efforts were dominated by cytology-based screening, the present and future of HPV-associated cancer prevention relies mostly on HPV vaccination and molecular screening tests. In this Review, we provide an overview of the epidemiology of HPV-associated cancers, their disease burden, how past and contemporary preventive interventions have shaped their incidence and mortality, and the potential for elimination. We particularly focus on the cofactors that could have the greatest effect on prevention efforts, such as parity and human immunodeficiency virus infection, as well as on social determinants of health. Given that the incidence of and mortality from HPV-associated cancers remain strongly associated with the socioeconomic status of individuals and the human development index of countries, elimination efforts are unlikely to succeed unless prevention efforts focus on health equity, with a commitment to both primary and secondary prevention.

Alcohol consumption and socioeconomic status associated with the risk of kidney cancer in a large Australian cohort study

PURPOSE

Studies have shown an inverse association between alcohol consumption and kidney cancer risk. We postulate that this inverse association may be further influenced by other risk factors.

METHODS

We used an Australian cohort, the 45 and Up Study recruited between 2005-2009 to investigate the association between alcohol consumption, and other potential risk factors and kidney cancer incidence. The median follow up was 5.4 years.

RESULTS

Of the 267 357 participants aged ≥45 years living in New South Wales, 497 were diagnosed with kidney cancer. There was a significant inverse association between alcohol consumption and risk of kidney cancer (p = 0.027), and a significant inverse dose-response relationship (p=0.011). There was significant interaction between alcohol consumption and socioeconomic status (p interaction = 0.001). Participants residing in higher socioeconomic areas (the two most advantaged quintiles) who consumed 8-10 drinks or >10 drinks per week, respectively, had a lower risk of kidney cancer compared to the group who consumed 1-4 drinks per week (HR 0.34, 95% CI 0.15-0.76, HR 0.51, 95% CI 0.31-0.83) with a dose-response trend of HR 0.62 (95% CI 0.42-0.93) per 7 drink increase in weekly alcohol consumption.

CONCLUSION

There could be an inverse association between alcohol consumption and risk in those residents in higher socioeconomic areas.

DATA AVAILABILITY

The data that support the findings of this study are available from the Sax Institute (https://www.saxinstitute.org.au/our-work/45-up-study/).

Mediating Role of Lifestyle Behaviors in the Association between Education and Cancer: Results from the European Prospective Investigation into Cancer and Nutrition

BACKGROUND

Many studies have shown that socioeconomic position (SEP) is associated with the incidence of malignant tumors at different sites. This study aims to estimate the association between educational level (as proxy for SEP) and cancer incidence and to understand whether the observed associations might be partially explained by lifestyle behaviors.

METHODS

The analyses were performed on data from the European Prospective Investigation into Cancer and Nutrition (EPIC) study, globally and by sex. We used Cox proportional hazards models together with mediation analysis to disentangle the total effect (TE) of educational level [measured through the Relative Index of Inequality (RII)] on cancer incidence into pure direct (PDE) and total indirect (TIE) effect, unexplained and explained by mediators, respectively. PDE and TIE were then combined to compute the proportions mediated (PM).

RESULTS

After an average of 14 years of follow-up, 52,422 malignant tumors were ascertained. Low educated participants showed higher risk of developing stomach, lung, kidney (in women), and bladder (in men) cancers, and, conversely, lower risk of melanoma and breast cancer (in post-menopausal women), when compared with more educated participants. Mediation analyses showed that portions of the TE of RII on cancer could be explained by site-specific related lifestyle behaviors for stomach, lung, and breast (in women).

CONCLUSIONS

Cancer incidence in Europe is determined at least in part by a socioeconomically stratified distribution of risk factors.

IMPACT

These observational findings support policies to reduce cancer occurrence by altering mediators, such as lifestyle behaviors, particularly focusing on underprivileged strata of the population.

Do Breast Cancer Patients Manage to Participate in an Outdoor, Tailored, Physical Activity Program during Adjuvant Breast Cancer Treatment, Independent of Health and Socio-Demographic Characteristics?

Exercise could reduce the side-effects of adjuvant breast cancer treatment; however, socio-demographic, health, and intervention conditions may affect patients' adherence to interventions. This study aimed to examine adherence to a 12-month outdoor post-surgery exercise program among newly diagnosed breast cancer patients during adjuvant treatment, and to identify socio-demographic and health-related predictors. In total, 47 women with invasive breast cancer stage I-II or ductal/lobular carcinoma grade 3 were included pre-surgery and randomized two weeks post-surgery to exercise (2 × 60 min/week). Patient characteristics (body-mass index (BMI), socioeconomic status, comorbidity, physical activity, and maximal oxygen uptake (VO2max)) were recorded pre-surgery. Correlations between adherence and patient characteristics and statistics for between-group differences were performed. The mean age was 54.2 years, mean BMI 27.8 kg/m2, and 54.2% received chemotherapy. Completers had a mean adherence of 81%, independent of season. Withdrawals (23%) occurred after a mean of 6.5 weeks (0-24 weeks), they were suggestively older, had lower socioeconomic status and pre-surgery VO2max, and higher BMI. Household income was significantly lower among withdrawals. There were insignificant correlations between adherence and health conditions. High adherence is achievable in a Nordic outdoor physical exercise program in breast cancer patients during adjuvant treatment, including chemotherapy. Additional studies are needed to clarify follow-up needs in some groups.

Socio-economic Inequality of Utilization of Cancer Testing in Europe: A Cross-Sectional Study

There are currently screening programmes for breast, cervical and colorectal cancer in many European countries. However, the uptake of cancer screening in general may vary within and between countries. The aim of this study is to assess the inequalities in testing utilization by socio-economic status and whether the amount of inequality varies across European regions. We conducted an analysis based on cross-sectional data from the second wave of the European Health Interview Survey from 2013 to 2015. We analysed the use of breast, cervical, and colorectal cancer testing by socio-economic position (household income, educational level and employment status), socio-demographic factors, self-perceived health and smoking behaviour, by using multinomial logistic models, and inequality measurement based on the Slope index of inequality (SII) and Relative index of inequality (RII). The results show that the utilization of mammography (Odds Ratio (OR) = 0.55, 95% confidence interval (95%CI):0.50–0.61), cervical smear tests (OR = 0.60, 95%CI:0.56–0.65) and colorectal testing (OR = 0.82, 95%CI:0.78–0.86) was overall less likely among individuals within a low household income compared to a high household income. Also, individuals with a non-EU country of birth, low educational level and being unemployed (or retired) were overall less likely to be tested. The income-based inequality in breast (SII = 0.191;RII = 1.260) and colorectal testing utilization (SII = 0.161;RII = 1.487) was the greatest in Southern Europe. For cervical smears, this inequality was greatest in Eastern Europe (SII = 0.122;RII = 1.195). We concluded that there is considerable inequality in the use of cancer tests in Europe, with inequalities associated with household income, educational level, employment status, and country of birth.

Breast Cancer Characteristics in the Population of Survivors Participating in the World Trade Center Environmental Health Center Program 2002-2019

The destruction of World Trade Center on 11 September 2001 exposed local community members to a complex mixture of known carcinogens and potentially carcinogenic substances. To date, breast cancer has not been characterized in detail in the WTC-exposed civilian populations. The cancer characteristics of breast cancer patients were derived from the newly developed Pan-Cancer Database at the WTC Environmental Health Center (WTC EHC). We used the Surveillance, Epidemiology, and End Results (SEER) Program breast cancer data as a reference source. Between May 2002 and 31 December 2019, 2840 persons were diagnosed with any type of cancer at the WTC EHC, including 601 patients with a primary breast cancer diagnosis (592 women and 9 men). There was a higher proportion of grade 3 (poorly differentiated) tumors (34%) among the WTC EHC female breast cancers compared to that of the SEER-18 data (25%). Compared to that of the SEER data, female breast cancers in the WTC EHC had a lower proportion of luminal A (88% and 65%, respectively), higher proportion of luminal B (13% and 15%, respectively), and HER-2-enriched (5.5% and 7%, respectively) subtypes. These findings suggest considerable differences in the breast cancer characteristics and distribution of breast cancer intrinsic subtypes in the WTC-exposed civilian population compared to that of the general population. This is important because of the known effect of molecular subtypes on breast cancer prognosis.

The impact of lifecourse socio-economic position and individual social mobility on breast cancer risk

BACKGROUND

Women with an advantaged socioeconomic position (SEP) have a higher risk of developing breast cancer (BC). The reasons for this association do not seem to be limited to reproductive factors and remain to be understood. We aimed to investigate the impact of lifecourse SEP from childhood and social mobility on the risk of BC considering a broad set of potential mediators.

METHODS

We used a discovery-replication strategy in two European prospective cohorts, E3N (N = 83,436) and EPIC-Italy (N = 20,530). In E3N, 7877 women were diagnosed with BC during a median 24.4 years of follow-up, while in EPIC-Italy, 893 BC cases were diagnosed within 15.1 years. Hazard ratios (HR) were estimated using Cox proportional hazard models on imputed data.

RESULTS

In E3N, women with higher education had a higher risk of BC (HR [95%CI] = 1.21 [1.12, 1.30]). This association was attenuated by adjusting for reproductive factors, in particular age at first childbirth (HR[95%CI] = 1.13 [1.04, 1.22]). Health behaviours, anthropometric variables, and BC screening had a weaker effect on the association. Women who remained in a stable advantaged SEP had a higher risk of BC (HR [95%CI] = 1.24 [1.07; 1.43]) attenuated after adjustment for potential mediators (HR [95%CI] = 1.13 [0.98; 1.31]). These results were replicated in EPIC-Italy.

CONCLUSIONS

These results confirm the important role of reproductive factors in the social gradient in BC risk, which does not appear to be fully explained by the large set of potential mediators, including cancer screening, suggesting that further research is needed to identify additional mechanisms.

Socioeconomic inequalities in cancer incidence in Europe: a comprehensive review of population-based epidemiological studies

Background

Since the end of the previous century, there has not been a comprehensive review of European studies on socioeconomic inequality in cancer incidence. In view of recent advances in data source linkage and analytical methods, we aimed to update the knowledge base on associations between location-specific cancer incidence and individual or area-level measures of socio-economic status (SES) among European adults.

Materials and methods

We systematically searched three databases (PubMed, Scopus and Web of Science) for articles on cancer incidence and SES. Qualitative synthesis was performed on the 91 included English language studies, published between 2000 and 2019 in Europe, which focused on adults, relied on cancer registry data and reported on relative risk (RR) estimates.

Results

Adults with low SES have increased risk of head and neck, oesophagogastric, liver and gallbladder, pancreatic, lung, kidney, bladder, penile and cervical cancers (highest RRs for lung, head and neck, stomach and cervix). Conversely, high SES is linked with increased risk of thyroid, breast, prostate and skin cancers. Central nervous system and haematological cancers are not associated with SES. The positive gap in testicular cancer has narrowed, while colorectal cancer shows a varying pattern in different countries. Negative associations are generally stronger for men compared to women.

Conclusions

In Europe, cancers in almost all common locations are associated with SES and the inequalities can be explained to a varying degree by known life-style related factors, most notably smoking. Independent effects of many individual and area SES measures which capture different aspects of SES can also be observed.

The association between socioeconomic position and tumour size, grade, stage, and mortality in Danish sarcoma patients - A national, observational study from 2000 to 2013

Background: Survival in sarcoma patients depends on a range of prognostic factors. An association between cancer survival and socioeconomic position is known for several other cancers. We therefore examined the relations between three socioeconomic factors and risk of presenting with known tumour related prognostic factors, and the overall mortality of the different socioeconomic and prognostic factors in 1919 patients diagnosed with sarcoma in Denmark 2000-2013.Material and methods: Patients with sarcoma in extremities or trunk wall aged 30 years or more at diagnosis were identified in the Danish Sarcoma Registry and linked on an individual level to Danish national registries. We obtained data on educational level, disposable income and cohabitation status. Odds ratios (ORs) were estimated for the association between the socioeconomic factors and grade, stage and tumour size. Hazard ratios (HRs) were estimated using Cox proportional hazard models.Results: In adjusted analyses, educational level, income and cohabitation status were not associated with high grade or dissiminated stage at time of diagnosis. However, living alone was statistically significantly associated with having a large soft tissue sarcoma (≥5 cm) at time of diagnosis (OR 1.51; CI1.12-2.03). The overall mortality was statistically significantly increased in the group of patients with ≤10 years of education (HR 1.27; CI 1.02-1.57), in patients with the 20% lowest income (HR 1.30; CI 1.00-1.67) and nearly in patients living alone (HR 1.16; CI 0.99-1.36).Conclusion: In this nationwide, multicentre, population-based study, soft tissue sarcoma patients living alone had greater risk of having a large tumour at time of diagnosis. Soft tissue and bone sarcoma patients with a short education, low income, or living alone, had a higher mortality. This might indicate that the social differences in mortality might be related to treatment aspects and the biology of the disease rather that the diagnostic process.

Combining individual and aggregated data to investigate the role of socioeconomic disparities on cancer burden in Italy

Quantifying socioeconomic disparities and understanding the roots of inequalities are growing topics in cancer research. However, socioeconomic differences are challenging to investigate mainly due to the lack of accurate data at individual-level, while aggregate indicators are only partially informative. We implemented a multiple imputation algorithm within a statistical matching framework that combines diverse sources of data to estimate individual-level associations between income and risk of breast and lung cancer, adjusting for potential confounding factors in Italy. The framework is computationally flexible and can be adapted to similar contexts.

Trends of colorectal cancer incidence by education and socioeconomic status in Finland

Background: The aim of this study was to investigate if the incidence of colorectal cancer (CRC) is associated with education and socioeconomic status (SES) in Finland, and if there are any changes in incidence differences between the groups over the period 1976-2014.Material and methods: CRC cases (N = 77,614) were retrieved from the Finnish Cancer Registry and linked with information on the education level and SES from Statistics Finland. We used Poisson regression model to quantify differences in incidence rates between the groups, and to assess changes over calendar time.Results and conclusions: Colon cancer incidence was higher among the highly educated, than in those with basic education. Similar differences were observed by SES in men. Incidence rates increased steeply over time among men with basic education (from 16.7/100,000 in 1976-1979 to 31.8 in 2010-2014), resulting in narrowed differences between the groups (p < .001). Incidence trends of proximal and distal colon and rectal cancer in men showed similar patterns. Heterogeneity across time periods by SES was observed only in colon cancer incidence in men (p = .009). No such large differences were detected in women. Steep increase in colon cancer incidence in men with basic education, and the respective persistent high incidence in the highly educated highlights the importance of focusing the preventive measures on modifiable lifestyle factors in order to reduce CRC incidence and to narrow the educational and socioeconomic health differences.

Changing patterns of breast cancer incidence and mortality by education level over four decades in Norway, 1971-2009

Background

In the last century, breast cancer incidence and mortality was higher among higher versus lower educated women in developed countries. Post-millennium, incidence rates have flattened off and mortality declined. We examined breast cancer trends by education level, to see whether recent improvements in incidence and mortality rates have occurred in all education groups.

Methods

We linked individual registry data on female Norwegian inhabitants aged 35 years and over during 1971–2009. Using Poisson models, we calculated absolute and relative educational differences in age-standardised breast cancer incidence and mortality over four decades. We estimated educational differences by Slope and Relative Index of Inequality, which correspond to rate difference and rate ratio, comparing the highest to lowest educated women.

Results

Pre-millennium, incidence and mortality of breast cancer were significantly higher in higher versus lower educated women. Post-millennium, educational differences in breast cancer incidence and mortality attenuated. During 2000–2009, breast cancer incidence was still 38% higher for higher versus lower educated women (Relative Index of Inequality: 1.38, 95% confidence interval: 1.31–1.44), but mortality no longer varied significantly by education level (Relative Index of Inequality: 1.09, 95% confidence interval: 0.99–1.19). Among women below 50 years, however, the education gradient for mortality reversed, and mortality was 28% lower for the highest versus lowest educated women during 2000–2009 (Relative Index of Inequality: 0.72, 95% confidence interval: 0.51–0.93).

Results

Post-millennium improvements in breast cancer incidence and mortality have primarily benefited higher educated women. Breast cancer mortality is now highest among the lowest educated women below 50 years.

Incidence and mortality of kidney cancer and its relationship with HDI (Human Development Index) in the world in 2012

Background and aims

Kidney cancer is among the cancers that have the highest growth rate in all age and racial groups in the world and is as the most deadly type of urinary tract cancer. Since awareness about this cancer incidence status and mortality is essential for better planning, this study aimed to investigate the incidence and mortality rate of kidney cancer and its relationship with the development index in the world in 2012.

Method

This study was an ecological study conducted based on GLOBOCAN project of the World Health Organization (WHO) for the countries in the world. The correlation between Standardized Incidence Rates (SIRs) and Standardized Mortality Rates (SMRs) of kidney cancer with HDI and its components was assessed using SPSS18.

Results

In total, 337,860 incidence cases (213,924 were men and 123,936 women) and 143,406 deaths (90,802 cases in men and 52,604 in women) of kidney cancer were recorded in 2012. A positive correlation of 0.731 was seen between SIR of kidney cancer and HDI (p≤0.001). Also, a negative correlation of 0.627 was seen between SMR of kidney cancer and HDI (p≤0.001).

Conclusion

The incidence and mortality rate of kidney cancer is higher in developed countries. A significant positive correlation has been seen between the standardized incidence and mortality rate of kidney cancer with the Human Development Index and its components. We need more studies to examine variation in incidence and mortality of kidney cancer and its related factors in the world.

The impacts of public mammography screening on the relationship between socioeconomic status and cancer stage

This study aimed to investigate the relationship between socioeconomic inequality and mortality following the introduction of a public mammography screening program in Norway by exploring the role of change in stage distribution as the mechanism for differences before and after the introduction of the screening program. Attained education level was used as a measure of socioeconomic status in this population-based study. All women aged 50–69 years diagnosed with breast cancer from 1999–2008 and with follow-up data until the end of 2009 were included. The primary endpoint was all-cause mortality. The results of a mediation analysis indicated that the introduction of screening led to stage distribution related reductions of −5.6 (95% confidence interval = −6.7 to −4.5), −2.5 (−3.0 to −2.1), and −1.4 (−1.9 to −0.9) fewer deaths per 1000 women for with a primary school education, secondary school education, and university education, respectively. The study showed that stage distribution explained −5 (−5.9 to −4.1) fewer deaths among women with a university education and −2.4 (−2.9 to −2.0) fewer deaths among women with a secondary school education before program implementation when compared to the group with a primary school education. There were significant reductions in mortality due to stage distribution after program implementation with differences relative to women with primary school of −1.8 (−2.2 to −1.4) and −0.7 (−0.9 to −0.5) fewer deaths in favor of women with university education and secondary school, respectively. The results indicate reduced importance of cancer stage as a reason for differences in mortality by socioeconomic status after the introduction of a public mammography program.

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The effects of breast cancer screening on socioeconomic inequality in survival are unknown.

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Stage and socioeconomic status in relation to the introduction of a screening program was examined.

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Mortality differences due to stage distribution were reduced after program implementation.

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Socioeconomic status by stage may be less important after screening introduction.

Socio-demographic and reproductive determinants of cervical neoplasia in seven sub-Sahara African countries

BACKGROUND

Since most human papilloma virus (HPV) infections regress without any intervention, HPV is a necessary but may not be a solely sufficient cause of cervical intraepithelial neoplasia (CIN) and cervical cancer. Hence, the influence of cofactors on progression from cervical HPV infection to high-grade CIN and invasive cervical cancer has been a subject of intensive research.

OBJECTIVE

We assessed the effect of socio-demographic and sexual reproductive factors on the prevalence of invasive cervical cancer and CIN diagnosed in cross-sectional cervical cancer screening projects carried out in seven sites of different sub-Saharan countries.

METHODS

Between January 2000 and August 2007, healthy women aged 25-59 who participated in the screening projects were interviewed for socio-demographic, reproductive, and behavioral characteristics, investigated for disease confirmation with colposcopy, and had biopsies directed from colposcopically abnormal areas by trained local physicians. Odds ratios (ORs) and their 95% confidence intervals (CIs) from logistic regression analyses were used to assess the effect of women characteristics on CIN 1, CIN 2-3, CIN 3, and invasive cancer outcome measures.

RESULTS

Among 47,361 women screened and investigated for disease confirmation, CIN 1 was diagnosed in 1,069 (2.3%), CIN 2 in 517 (1.1%), CIN 3 in 175 (0.5%), and invasive cancer in 485 (1.0%). The site-specific prevalence of CIN 2-3 lesions ranged from 0.3 to 5.1% and from 0.2 to 1.9% for invasive cancers. Risk factors for CIN 2-3 were being widowed or separated versus currently married (OR 1.3, 95% CI 1.0-1.7 a); and having had at least four pregnancies versus zero or one pregnancy (OR at least 1.4-fold, 95% CI 1.1-1.8). Risk factors for invasive cancer were being widowed or separated versus currently married (OR 2.0, 95% CI 1.3-3.1); and having had at least three pregnancies versus zero or one pregnancy (OR at least 3.0-fold, 95% CI 2.1-4.2). Additionally, cervical cancer risk increased with increasing age, age at menarche, and age at marriage, while the risk decreased with increasing level of education and in those with some form of employment compared to housewives.

CONCLUSION

The exposure of the exocervix and/or the increased levels of estrogen and progesterone for more prolonged periods during pregnancy in multiparous women and the vulnerability of widowed/separated women in society might result in increased risk of cervical neoplasia more so among women exposed to HPV infection. High parity probably explains the persistently high rates of cervical cancer in sub-Saharan Africa.

Involvement of genetic factors and lifestyle on the occurrence of colorectal and gastric cancer

Gastrointestinal cancers are diseases due to genetic and environmental factors. In this present work we are interested in the influence of environmental factors on the occurrence of gastrointestinal cancers in Tunisian population. We found that the MTHFR C677T polymorphism was associated with colorectal cancer (P<0.04) but not with gastric cancer. In addition, we have shown that alcohol is associated with an increased risk of colorectal cancer, but the consumption of cheese is protective. Furthermore, we studied tymidylate synthase gene involved in folate metabolism. Indeed, we observed that the 5'UTR repeat polymorphism, is associated with risk of colorectal cancer, and the LL genotype (3R/3R) was significantly frequent in patients with colorectal cancer compared to controls (p=0.002; OR=2.7, 95% CI=1.4-5.2). While we found that SL genotype (2R/3R) was associated with risk of gastric cancer (p=0.015; OR=4.46, 95% CI=1.08-19-64). This polymorphism was also shown to be a predictor of response to chemotherapy based 5'-fluorouracil. However, we are interested in studying the GPX -1 gene involved in phase I metabolism of xenobiotics. We therefore evaluated the risk of TT genotype in GPX-1 C599T polymorphism with the onset of gastric cancer (P=0.0001; OR=5.41, 95% CI 1.98 to 15.58) and colorectal cancer (P=0.00008; OR=4.40, 95% CI 1.93 to 10.27). To clarify the possible relationship between environmental factors and the occurrence of the disease, we studied the additive effect of risk genotype and behavior in order to highlight the interaction of gene-environment factors.

The Influence of Serum Cortisol Level Onto Perceptive Experience of Optimism in Patients with Newly Diagnosed Cancer

THE AIM

The aim of this study is to investigate the correlation between the morning level of serum cortisol and perceptive experience of optimism in a selected group of 60 patients with newly diagnosed cancer who were treated at Mostar University Clinical Hospital during a one-month period.

PATIENTS AND METHODS

The morning level of serum cortisol was measured in all patients following the verification of oncological disease. The patients also filled out a questionnaire of socio-demographic data, as well as the scales for optimism/pessimism assessment.

RESULTS

The average morning serum cortisol level was within the reference values in the majority of patients, independently of their perceptive experience of optimism/pessimism. There was no significant difference in the morning level of serum cortisol among the subgroups of patients high and low on the scale of optimism, as well as the scale of pessimism. No correlation existed between the serum cortisol morning level and expressed optimism/pessimism, as well. The great majority of respondents had secondary and lower education, was retired or unemployed, and suffered lower socio-economic conditions of life. Therefore, their access to medical information and their knowledge of cancer modern treatment options and possibilities were restricted, what may also have an influence onto perceptive experience of optimism/pessimism.

CONCLUSION

The results concerned with the perceptive experience of optimism/pessimism assessment were not a consequence of stress reaction but they were more correlated to general personal characteristics, the level of education, and socio-economic status of patients. The results do not confirm the impact of morning serum cortisol level onto physiological reactions to stressful conditions and situations in selected group of patients with de novo carcinoma.

Socioeconomic disparities in breast cancer incidence and survival among parous women: findings from a population-based cohort, 1964-2008

Background

Socioeconomic position (SEP) has been associated with breast cancer incidence and survival. We examined the associations between two socioeconomic indicators and long-term breast cancer incidence and survival in a population-based cohort of parous women.

Methods

Residents of Jerusalem who gave birth between 1964–1976 (n = 40,586) were linked to the Israel Cancer Registry and Israel Population Registry to determine breast cancer incidence and vital status through mid-2008. SEP was assessed by husband’s occupation and the woman’s education. We used log ranks tests to compare incidence and survival curves by SEP, and Cox proportional hazard models to adjust for demographic, reproductive and diagnostic factors and assess effect modification by ethnic origin.

Results

In multivariable models, women of high SEP had a greater risk of breast cancer compared to women of low SEP (Occupation: HR 1.18, 95 % CI 1.03-1.35; Education: HR 1.39, 95 % CI 1.21-1.60) and women of low SEP had a greater risk of mortality after a breast cancer diagnosis (Occupation: HR 1.33, 95 % CI 1.04-1.70; Education: HR 1.37, 95 % CI 1.06-1.76). The association between education and survival was modified by ethnic origin, with a gradient effect observed only among women of European origin. Women of Asian, North African and Israeli origin showed no such trend.

Conclusions

SEP was associated with long-term breast cancer incidence and survival among Israeli Jews. Education had a stronger effect on breast cancer outcomes than occupation, suggesting that a behavioral mechanism may underlie disparities. More research is needed to explain the difference in the effect of education on survival among European women compared to women of other ethnicities.

Educational differentials in cancer mortality and avoidable deaths in Lithuania, 2001-2009: a census-linked study

OBJECTIVES

We investigate relative mortality inequalities by education for detailed cancer sites and provide estimates of deaths which could have been avoided through the elimination of these inequalities.

METHODS

A census-linked dataset based on a follow-up of all residents registered in the 2001 census was used for the analysis. Mortality rate ratios were estimated by employing multivariate Poisson regression models for count data.

RESULTS

An inverse educational gradient was observed for 11 cancer sites among men and for three cancer sites among women. Substantial shares of these cancer deaths would have been avoided if mortality among less educated groups had been the same as mortality among highly educated groups.

CONCLUSIONS

Cancer control plans must consider socioeconomic inequalities and propose ways to improve prevention measures aimed at disadvantaged groups.

Existing data sources in clinical epidemiology: the Scandinavian Thrombosis and Cancer Cohort

Background

Although venous thromboembolism (VTE) is a known common complication in cancer patients, there is limited knowledge on patient-related and cancer-specific risk factors in the general population. The Scandinavian Thrombosis and Cancer (STAC) Cohort was established by merging individual data from three large Scandinavian cohorts (The Tromsø Study, the second Nord-Trøndelag Health Study, and the Danish Diet, Cancer and Health Study). Here, we present the profile of the STAC cohort and provide age-specific incidence rates of VTE and cancer.

Methods

The STAC cohort includes 144,952 subjects aged 19–101 years without previous VTE or cancer. Baseline information collected in 1993–1997 included physical examination, self-administered questionnaires, and blood samples. Validated VTE events and cancer diagnoses were registered up to 2007–2012.

Results

There were 2,444 VTE events (1.4 per 1,000 person-years [PY]) during follow-up, and the incidence increased exponentially from 0.3 per 1,000 PY in subjects aged 20–29 years to 6.4 per 1,000 PY in subjects aged 80+. Overall, 51% of the VTE events were provoked, and cancer was the most common provoking factor (19%), followed by immobilization and surgery (both 15%). In total, 19,757 subjects developed cancer during follow-up (9.8 per 1,000 PY), and the 5-year age-specific incidence rates of cancer were coherent with corresponding rates from the Norwegian Cancer Registry.

Conclusion

The STAC cohort will provide a unique opportunity to explore the epidemiology and impact of genetic and environmental patient-related and cancer-specific risk factors for VTE in the general population.

Relationship between alcohol-attributable disease and socioeconomic status, and the role of alcohol consumption in this relationship: a systematic review and meta-analysis

Background

Studies show that alcohol consumption appears to have a disproportionate impact on people of low socioeconomic status. Further exploration of the relationship between alcohol consumption, socioeconomic status and the development of chronic alcohol-attributable diseases is therefore important to inform the development of effective public health programmes.

Methods

We used systematic review methodology to identify published studies of the association between socioeconomic factors and mortality and morbidity for alcohol-attributable conditions. To attempt to quantify differences in the impact of alcohol consumption for each condition, stratified by SES, we (i) investigated the relationship between SES and risk of mortality or morbidity for each alcohol-attributable condition, and (ii) where, feasible explored alcohol consumption as a mediating or interacting variable in this relationship.

Results

We identified differing relationships between a range of alcohol-attributable conditions and socioeconomic indicators. Pooled analyses showed that low, relative to high socioeconomic status, was associated with an increased risk of head and neck cancer and stroke, and in individual studies, with hypertension and liver disease. Conversely, risk of female breast cancer tended to be associated with higher socioeconomic status. These findings were attenuated but held when adjusted for a number of known risk factors and other potential confounding factors. A key finding was the lack of studies that have explored the interaction between alcohol-attributable disease, socioeconomic status and alcohol use.

Conclusions

Despite some limitations to our review, we have described relationships between socioeconomic status and a range of alcohol-attributable conditions, and explored the mediating and interacting effects of alcohol consumption where feasible. However, further research is needed to better characterise the relationship between socioeconomic status alcohol consumption and alcohol-attributable disease risk so as to gain a greater understanding of the mechanisms and pathways that influence the differential risk in harm between people of low and high socioeconomic status.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-1720-7) contains supplementary material, which is available to authorized users.

Social inequalities and smoking-associated breast cancer - Results from a prospective cohort study

OBJECTIVE

The association between smoking and breast cancer has been found in most recent, large cohort studies. We wanted to investigate how smoking-associated breast cancer varies by level of education, a well-established measure of socioeconomic status.

METHODS

We included 302,865 women with 7490 breast cancer cases. Participants were assigned to low, moderate or high level of education and analyzed by smoking status (ever/never), and stratified by birth cohorts (≤1950>). We used Cox proportional hazard to estimate hazard ratios (HRs) and confidence intervals (CIs), adjusting for age, number of children, age at first childbirth, BMI, age at enrollment and physical activity.

RESULTS

Women born ≤1950 with low and moderate levels of education had a 40% increase in smoking-associated breast cancer risk (HR=1.40, 95% CI 1.25-1.57 and HR=1.14, 95% CI 1.05-1.24, respectively). Women in the same age group with high level of education did not have an increase in risk. No increased breast cancer risk was found among women born after 1950 for any level of education, when analyzed by smoking status. Longer duration of smoking before first childbirth was consistently associated with increasing risk of breast cancer in all three categories of education (all p for trends<0.01).

CONCLUSION

Smoking for several years before first childbirth increases the risk of breast cancer, regardless of educational level.

Changing inequalities in cervical cancer: modeling the impact of vaccine uptake, vaccine herd effects, and cervical cancer screening in the post-vaccination era

BACKGROUND

Inequalities in cervical cancer may be increased following mass vaccination against the human papillomavirus (HPV) if girls with low vaccine uptake also have low future participation in cervical cancer screening. We evaluated how vaccine uptake distribution affects inequalities in squamous cell carcinoma (SCC) incidence between groups with different screening participation.

METHODS

We used an individual-based transmission dynamic model of HPV infection and disease (HPV-ADVISE). Females were stratified by routine screening frequency. We modeled the impact of vaccination on SCC incidence rate differences (absolute inequality) and incidence rate ratios (relative inequality) between women who have routine screening intervals of <5 years (frequently screened), ≥5 years (underscreened), and who are never screened. We compared simulations with uniform vaccine uptake with scenarios with unequal vaccine uptake, in which never and underscreened women have lower vaccine uptake than frequently screened women.

RESULTS

Absolute SCC inequalities between groups with different screening rates were predicted to decrease after vaccination, even when women with the lowest screening participation had the lowest vaccine uptake. Herd effects helped reduce absolute inequalities when vaccine uptake was unequal. Conversely, relative SCC inequalities remained unchanged or increased after vaccination. Results were robust to different overall vaccination coverages and sexual mixing scenarios.

CONCLUSION

Though mass HPV vaccination is predicted to substantially decrease SCC incidence rates, never screened women will still have the highest disease burden after vaccination.

IMPACT

To reduce both absolute and relative SCC inequalities, public health initiatives will need to address inequalities in both vaccine uptake and in cervical cancer screening participation.

Time trends in socioeconomic inequalities in cancer mortality: results from a 35 year prospective study in British men

Background

Socioeconomic inequalities in cancer mortality in Britain have been shown to be present in the 1990s and early 2000s. Little is known about on-going patterns in such inequalities in cancer mortality. We examined time trends in socioeconomic inequalities in cancer mortality in Britain between 1978 and 2013.

Methods

A socially representative cohort of 7489 British men with data on longest-held occupational social class, followed up for 35 years, in whom 1484 cancer deaths occurred.

Results

The hazard ratio for cancer mortality for manual vs. non-manual social classes remained unchanged; among men aged 50–59 years it was 1.62 (95%CI 1.17–2.24) between 1980–1990 and 1.65 (95%CI 1.14–2.40) between 1990–2000. The absolute difference (non-manual minus manual) in probability of surviving death from cancer to 70 years remained at 3% over the follow-up. The consistency of risks over time was similar for both smoking-related and non-smoking related cancer mortality.

Conclusion

Socioeconomic inequalities in cancer mortality in Britain remain unchanged over the last 35 years and need to be urgently addressed.

Socioeconomic status and cutaneous malignant melanoma in Northern Europe

Socioeconomic status (SES) is associated with cutaneous malignant melanoma (CMM) in Northern Europe, despite equal access to health care. SES per se is not responsible for this association, which must be ascribed to important risk factors for CMM such as intermittent ultraviolet radiation (UVR) exposure, and screening for CMM possibly owing to a greater knowledge and understanding of CMM. Our review of the literature showed that high SES is associated with increased risk of CMM, thinner tumours, increased survival and decreased mortality from CMM - the latter shown among women, and in recent studies also among men. There is evidence that high SES is associated with sun holidays, whereas low SES is associated with the use of sunbeds. Findings suggest that high SES is associated with the use of physicians and dermatologists for marks and moles, possibly owing to more knowledge and better understanding of CMM. We conclude that there has been a true increase in CMM incidence among high SES individuals in Northern Europe probably due to past intense intermittent UVR exposure, especially in connection with sun holidays. However, the increased risk of CMM and a better outcome of CMM in high SES individuals may also be conditioned by frequent recourse to physicians, which may be ascribed to more knowledge and better understanding of CMM, although more studies on this subject are warranted. Thicker CMM tumours and increased CMM mortality among low SES individuals in recent decades may reflect exposure to intermittent UVR, such as the use of sunbeds, as well as delayed diagnosis.

Physical activity and the risk of postmenopausal breast cancer - the Norwegian Women and Cancer Study

Background

The relationship between physical activity (PA) throughout life and the risk of postmenopausal breast cancer overall and by estrogen receptor (ER) and progesterone receptor (PR) status, has been reported, but without consistent results. The present study aimed to investigate PA from young age to adulthood in participants of the Norwegian Women and Cancer (NOWAC) Study, in order to determine whether changes in PA level affect the risk of postmenopausal breast cancer.

Methods

1767 invasive breast cancer cases were identified among 80,202 postmenopausal participants of the NOWAC Study during 8.2 years of median follow-up. PA levels at age 14 years, 30 years and at cohort enrollment were obtained via a self-administered questionnaire. Multivariate Cox proportional hazard regression models were used to estimate relative risks and 95% confidence intervals of the risk of postmenopausal breast cancer overall and by ER/PR status.

Results

Risk of postmenopausal breast cancer overall and by ER/PR status was not associated with physical activity level at enrollment. Women with a low PA level at age 30 had an increased risk of ER+/PR + breast tumors (P for trend = 0.04) compared to women with a moderate physical activity level at age 30. Women with a low physical activity level at all three periods of life had a 20% significantly reduced risk of postmenopausal breast cancer, as well as a reduced risk of ER+/PR + and ER+/PR- breast tumors, compared with women who maintained a moderate physical activity level. However, when analyses were corrected for multiple tests, the result was no longer statistically significant. The findings were consistent over strata of age, body mass index and use of hormone replacement therapy.

Conclusions

The study results from this large Norwegian cohort do not support an association between physical activity at different periods of life and the risk of postmenopausal breast cancer.

Social disparity in breast and ovarian cancer incidence in iran, 2003-2009: a time trend province-level study

Purpose

This pioneering study aimed to investigate social disparities in breast cancer (BC) and ovarian cancer (OC) incidence rates among women across Iran's provinces from 2003 to 2009.

Methods

Provincial level population distribution data pertaining to women were obtained from the Statistical Centre of Iran. Age-standardized incidence rates of BC and OC were gathered from the National Cancer Registry. Human Development Index was used as the provinces' social rank (SR), and rate ratio and Kunst and Mackenbach relative index of inequality were used to assess social disparities. Annual percentage change (APC) was calculated using joinpoint regression, and Spearman rank correlation was used to examine the association between APC and SR.

Results

It was found that over the study period, annual incidence rates rose by 11.6% and 9.7% for BC and OC, respectively. Social disparities were substantial and stable in favor of provinces with lower SR in Iran, and were more profound for BC than OC. Correlations between APC and SR were small and nonsignificant for both BC and OC.

Conclusion

The results showed that both BC and OC incidence increased in Iran during 2003 to 2009. There were positive associations between BC and OC incidence rates and the provinces' SR. This study's recommendations provide valuable information for health resource allocation pertaining to BC and OC control programs across provinces in Iran.

Educational differences in postmenopausal breast cancer--quantifying indirect effects through health behaviors, body mass index and reproductive patterns

Studying mechanisms underlying social inequality in postmenopausal breast cancer is important in order to develop prevention strategies. Standard methods for investigating indirect effects, by comparing crude models to adjusted, are often biased. We applied a new method enabling the decomposition of the effect of educational level on breast cancer incidence into indirect effects through reproductive patterns (parity and age at first birth), body mass index and health behavior (alcohol consumption, physical inactivity, and hormone therapy use). The study was based on a pooled cohort of 6 studies from the Copenhagen area including 33,562 women (1,733 breast cancer cases) aged 50-70 years at baseline. The crude absolute rate of breast cancer was 399 cases per 100,000 person-years. A high educational level compared to low was associated with 74 (95% CI 22-125) extra breast cancer cases per 100,000 person-years at risk. Of these, 26% (95% CI 14%-69%) could be attributed to alcohol consumption. Similar effects were observed for age at first birth (32%; 95% CI 10%-257%), parity (19%; 95%CI 10%-45%), and hormone therapy use (10%; 95% CI 6%-18%). Educational level modified the effect of physical activity on breast cancer. In conclusion, this analysis suggests that a substantial number of the excess postmenopausal breast cancer events among women with a high educational level compared to a low can be attributed to differences in alcohol consumption, use of hormone therapy, and reproductive patterns. Women of high educational level may be more vulnerable to physical inactivity compared to women of low educational level.

Socioeconomic status and lung cancer: unraveling the contribution of genetic admixture

OBJECTIVES

We examined the relationship between genetic ancestry, socioeconomic status (SES), and lung cancer among African Americans and Latinos.

METHODS

We evaluated SES and genetic ancestry in a Northern California lung cancer case-control study (1998-2003) of African Americans and Latinos. Lung cancer case and control participants were frequency matched on age, gender, and race/ethnicity. We assessed case-control differences in individual admixture proportions using the 2-sample t test and analysis of covariance. Logistic regression models examined associations among genetic ancestry, socioeconomic characteristics, and lung cancer.

RESULTS

Decreased Amerindian ancestry was associated with higher education among Latino control participants and greater African ancestry was associated with decreased education among African lung cancer case participants. Education was associated with lung cancer among both Latinos and African Americans, independent of smoking, ancestry, age, and gender. Genetic ancestry was not associated with lung cancer among African Americans.

CONCLUSIONS

Findings suggest that socioeconomic factors may have a greater impact than genetic ancestry on lung cancer among African Americans. The genetic heterogeneity and recent dynamic migration and acculturation of Latinos complicate recruitment; thus, epidemiological analyses and findings should be interpreted cautiously.

Socioeconomic position and incidence of gastric cancer: a systematic review and meta-analysis

BACKGROUND

Low socioeconomic position (SEP) has been associated with increased risks of morbidity and mortality from many diseases. We investigated the associations between gastric cancer incidence and education, occupation and income as indicators for SEP.

METHODS

We searched the PubMed and EMBASE databases for studies on SEP and gastric cancer incidence published from 1966 through February 2013. We used a random-effect model to pool the risk estimates from the individual studies. The relative indexes of inequality (RIIs) with their 95% CIs were used as summary estimates. We stratified the analysis by SEP indicators, sex, country's income group, geographical area, level of adjustment for an established risk factor, publication year, study design, type of control and length of follow-up.

RESULTS

Of 1549 citations, 36 studies met our inclusion criteria. We observed an increased risk of gastric cancer among the lowest SEP categories in education (RII=2.97; 95% CI 1.923 to 4.58), occupation (RII=4.33; 95% CI 2.57 to 7.29) and combined SEP (RII=2.64; 95% CI 1.05 to 6.63) compared with the highest SEP categories. Although the association between the incidence of gastric cancer and the level of income is evident, it did not reach a statistically significant level (RII=1.25; 95% CI 0.93 to 1.68).

CONCLUSIONS

We found that the risk of gastric cancer incidence is higher among low SEP groups.

Trends in Cervical Cancer Mortality by Socioeconomic Status in Korean Women between 1998 and 2009

Background

Death from uterine cervical cancer could be preventable by an active participation of women at risk in a screening program such as the Papanicolaou test. In order to examine the presence of socioeconomic disparity in preventable deaths, we evaluated the time trends of cervical cancer mortality by socioeconomic status in Korean women.

Methods

We selected level of educational attainment and marital status as surrogate indices of socioeconomic status. Using death certificate data and Korean Population and Housing Census data from Korea National Statistical office, we calculated age-standardized yearly mortality rates from cervical cancer between 1998 and 2009 according to the level of education as well as marital status.

Results

Cervical cancer mortality peaked in 2003 and then decreased gradually over time. Cervical cancer mortality was the highest in the group with the lowest level of educational attainment in all age groups and the gap between the lowest and the highest educational level has increased over time. Cervical cancer mortality was lower in married women than unmarried women in all age groups, and the degree of difference did not change over time.

Conclusion

In the Korean population, socioeconomic differential in cervical cancer mortality has persisted over time.

Update on the current state of melanoma incidence

The incidence of melanoma is rising worldwide, and in the United States has increased by approximately 2.8% annually since 1981. Melanoma is more common in whites, and is generally more prevalent in men. However, there is a 6.1% annual increase in US incidence of melanomas in white women younger than age 44, with growing concern that increases in skin cancer in younger women may reflect recent trends in indoor tanning. Melanoma incidence is also greater in higher economic groups. Globally, melanoma incidence is highest in Australia, followed by the United States and parts of Europe.

Association of time since last birth, age at first birth and parity with breast cancer survival among parous women: a register-based study from Norway

Reproductive factors that have a well-documented effect on breast cancer risk may also influence the prognosis of the disease, but previous studies on breast cancer survival have yielded conflicting results. We combined information from two population-based registries and obtained information on 16,970 parous women with invasive breast cancer. Cox regression analysis was used to assess breast cancer survival in relation to age at diagnosis, age at first birth, time since last birth and parity. We stratified the analyses by age at diagnosis (<50 and ≥ 50 years) as an approximation for menopausal age. In women diagnosed before 50 years of age, breast cancer survival was reduced with younger age at diagnosis (p for trend <0.001), whereas in women diagnosed at 50 years or later, survival was reduced with older age at diagnosis (p for trend 0.011). For breast cancer diagnosed before 50 years, survival was poorer in women with four or more births compared to women with one or two births (hazard ratio 1.3, 95% confidence interval 1.1-1.6). A short time since last birth was associated with reduced survival (p for trend 0.05), but adjustment for stage and grade attenuated the association. Among women diagnosed at 50 years or later, we found no association with survival for any of the reproductive factors. In summary, reproductive factors were associated with survival from breast cancer diagnosed before but not after age 50 years. Young women had a particularly poor prognosis throughout the study period.

Educational level and risk of colorectal cancer in EPIC with specific reference to tumor location

Existing evidence is inconclusive on whether socioeconomic status (SES) and educational inequalities influence colorectal cancer (CRC) risk, and whether low or high SES/educational level is associated with developing CRC. The aim of our study was to investigate the relationship between educational level and CRC. We studied data from 400,510 participants in the EPIC (European Prospective Investigation into Cancer and Nutrition) study, of whom 2,447 developed CRC (colon: 1,551, rectum: 896, mean follow-up 8.3 years). Cox proportional hazard regression analysis stratified by age, gender and center, and adjusted for potential confounders were used to estimate hazard ratios (HR) and 95% confidence intervals (95%CI). Relative indices of inequality (RII) for education were estimated using Cox regression models. We conducted separate analyses for tumor location, gender and geographical region. Compared with participants with college/university education, participants with vocational secondary education or less had a nonsignificantly lower risk of developing CRC. When further stratified for tumor location, adjusted risk estimates for the proximal colon were statistically significant for primary education or less (HR 0.73, 95%CI 0.57-0.94) and for vocational secondary education (HR 0.76, 95%CI 0.58-0.98). The inverse association between low education and CRC risk was particularly found in women and Southern Europe. These associations were statistically significant for CRC, for colon cancer and for proximal colon cancer. In conclusion, CRC risk, especially in the proximal colon, is lower in subjects with a lower educational level compared to those with a higher educational level. This association is most pronounced in women and Southern Europe.

The enduring and evolving relationship between social class and breast cancer burden: a review of the literature

INTRODUCTION

Breast cancer in women has historically been seen as a "cancer of affluence" and there is a well-documented higher incidence among women of higher social class, as well as in societies with higher resources. However, the relationship between social class and breast cancer disease characteristics, especially those associated with poorer prognosis, is less well documented, and the overall relationship between breast cancer mortality and social class has been shown to vary. Furthermore, rapid changes in women's health and health-related behaviors in societies around the world may have an impact on both incidence and mortality patterns for breast cancer in the future.

METHODS

A PUBMED search on breast cancer and social class (incorporating the MeSH-nested concept of SES) yielded 403 possible studies published between 1978 and 2009, of which 90 met criteria for review. Our review discusses conceptualization and measurement of women's social class in each study, as well as findings related to breast cancer incidence, tumor biology or mortality, associated with social class.

FINDINGS

We found mostly consistent evidence that breast cancer incidence continues to be higher in higher social class groups, with some modification of risk with adjustment for known risk factors, including physical activity and reproductive history. However, biologic characteristics associated with poorer prognosis were negatively associated with social class (i.e., greater occurrence among disadvantaged women), and mortality from breast cancer showed inconsistent relationship to social class.

CONCLUSIONS

We discuss these studies in relation to the growing burden of breast cancer among low resource groups and countries, and the need for cancer control strategies reflecting the emerging demographics of breast cancer risk.

Socioeconomic position and lifestyle in relation to breast cancer incidence among postmenopausal women: a prospective cohort study, Denmark, 1993-2006

BACKGROUND

In Denmark, the incidence of breast cancer is higher among women with higher socioeconomic position. We investigated whether differences in exposure to certain risk factors contribute to this gradient, as measured from education, income and occupation.

METHODS

We conducted a cohort study of 23,111 postmenopausal women aged 50-65 years who were enrolled in the prospective Danish 'Diet, Cancer and Health' study between 1993 and 1995. At baseline, all women filled in a questionnaire on lifestyle and food frequency. The results were analysed in Cox proportional hazard models.

RESULTS

Part of the association with socioeconomic position is due to the potential mediators reproductive pattern, use of hormone replacement therapy and alcohol consumption. After simultaneous adjustment for these factors, the hazard ratios were 1.06 (95% confidence interval [CI], 0.88-1.27) for women with higher education and 1.07 (95% CI, 0.85-1.34) for women with higher income. The HR ratio for women working as higher officials when compared with unskilled workers was 1.23 (0.96-1.59).

CONCLUSION

The results support the hypothesis that the higher incidence of breast cancer among socially advantaged women is mediated partly by differences in exposure to reproductive factors, hormone replacement therapy and alcohol.

The contribution of risk factors to the higher incidence of invasive and in situ breast cancers in women with higher levels of education in the European prospective investigation into cancer and nutrition

The authors investigated the role of known risk factors in educational differences in breast cancer incidence. Analyses were based on the European Prospective Investigation Into Cancer and Nutrition and included 242,095 women, 433 cases of in situ breast cancer, and 4,469 cases of invasive breast cancer. Reproductive history (age at first full-term pregnancy and parity), exposure to endogenous and exogenous hormones, height, and health behaviors were accounted for in the analyses. Relative indices of inequality (RII) for education were estimated using Cox regression models. A higher risk of invasive breast cancer was found among women with higher levels of education (RII = 1.22, 95% confidence interval (CI): 1.09, 1.37). This association was not observed among nulliparous women (RII = 1.13, 95% CI: 0.84, 1.52). Inequalities in breast cancer incidence decreased substantially after adjusting for reproductive history (RII = 1.11, 95% CI: 0.98, 1.25), with most of the association being explained by age at first full-term pregnancy. Each other risk factor explained a small additional part of the inequalities in breast cancer incidence. Height accounted for most of the remaining differences in incidence. After adjusting for all known risk factors, the authors found no association between education level and risk of invasive breast cancer. Inequalities in incidence were more pronounced for in situ breast cancer, and those inequalities remained after adjustment for all known risk factors (RII = 1.61, 95% CI: 1.07, 2.41), especially among nulliparous women.

Interaction of area-level socioeconomic status and UV radiation on melanoma occurrence in California

BACKGROUND

Melanoma incidence has been correlated strongly and positively with both socioeconomic status (SES) and lower latitude and other measures of ambient UV radiation (UVR). However, because high-SES populations may be colocated in areas of high UVR, we assessed their joint influences on melanoma occurrence to better target subpopulations for melanoma education and screening.

METHODS

We obtained from the California Cancer Registry information regarding 23,564 incident cases of invasive cutaneous melanoma among non-Hispanic white residents between January 1, 1998, and December 31, 2002. We geocoded each case based on residence at diagnosis and linked previously tested neighborhood measures of SES and average annual UVR to calculate age-adjusted incidence rates, rate ratios, and the corresponding 95% confidence intervals. Poisson regression was used to calculate multivariately adjusted rate ratios.

RESULTS

UVR was significantly and positively associated with melanoma incidence only among persons living in the top 40% of California neighborhoods ranked by SES. People in neighborhoods of the highest SES and UVR categories had 60% higher rates of melanoma than those from neighborhoods in the lowest categories (rate ratio, 1.60; 95% confidence interval, 1.02-2.51).

CONCLUSION

Our findings indicate that UVR and SES interact to influence melanoma occurrence and suggest that socioeconomic gradients in melanoma incidence are not explained entirely by UVR.

IMPACT

Cancer prevention and early detection educational efforts should be targeted to high-SES groups in areas of high UVR exposure. Contextual measures of both SES and UVR should be considered important determinants of melanoma occurrence in future studies.

Socioeconomic status and changing inequalities in colorectal cancer? A review of the associations with risk, treatment and outcome

BACKGROUND

Upcoming mass screening for colorectal cancer (CRC) makes a review of recent literature on the association with socioeconomic status (SES) relevant, because of marked and contradictory associations with risk, treatment and outcome.

METHODS

The Pubmed database using the MeSH terms 'Neoplasms' or 'Colorectal Neoplasms' and 'Socioeconomic Factors' for articles added between 1995 and 1st October 2009 led to 62 articles.

RESULTS

Low SES groups exhibited a higher incidence compared with high SES groups in the US and Canada (range risk ratio (RR) 1.0-1.5), but mostly lower in Europe (RR 0.3-0.9). Treatment, survival and mortality all showed less favourable results for people with a lower socioeconomic status: Patients with a low SES received less often (neo)adjuvant therapy (RR ranging from 0.4 to 0.99), had worse survival rates (hazard ratio (HR) 1.3-1.8) and exhibited generally the highest mortality rates up to 1.6 for colon cancer in Europe and up to 3.1 for rectal cancer.

CONCLUSIONS

A quite consistent trend was observed favouring individuals with a high SES compared to those with a low SES that still remains in terms of treatment, survival and thus also mortality. We did not find evidence that the low/high SES gradients for treatment chosen and outcome are decreasing. To meet increasing inequalities in mortality from CRC in Europe for people with a low SES and to make mass screening successful, a high participation rate needs to be realised of low SES people in the soon starting screening program.

Data on education: From population statistics to epidemiological research

Background: Level of education is in many fields of research used as an indicator of social status. Methods: Using Statistics Denmark’s register for education and employment of the population, we examined highest completed education with a birth-cohort perspective focusing on people born between 1930 and 1974. Results: Irregularities in the educational data were found for both men and women born from 1951 to 1957. For the birth cohorts born from 1951 to 1954, a sudden increase in the proportion of persons with basic school education only was seen, and a following decrease in this proportion was seen for the birth cohorts born from 1955 to 1957. For the same birth cohorts, a reverse curve was found for the proportion with vocational training as highest completed education. Using proportion of women with at least one child at the age of 30, our analysis illustrated that spurious patterns may emerge when other social phenomena are analysed by partly misclassified educational groups. Conclusions: Our findings showed that register data are not always to be taken at face value and that thorough analysis may unravel unexpected irregularities. Although such data errors may be remedied in analyses of population trends by use of extrapolated values, solutions are less obvious in epidemiological research using individual level data.

An epidemiological study to identify the risk factors with two different types of controls in high-grade cervical lesions including invasive cancer

A multidisciplinary study on pre-cancerous and early cancerous lesions of uterine cervix was carried out at our Institute from which the subjects (cases and one group of control) for the present study were selected with the objective to identify the possible risk factors related to high-grade cervical lesions including invasive cancer through an epidemiological study by selecting two different types of controls and to assess the feasibility whether the cancers of other organs could be taken as controls at the same time studying the risk factors associated with cervical cancer. One group of control was women with negative Pap smear and second group of control was the women with breast cancer but negative Pap smear. A total of 100 biopsy-proven cases of high-grade cervical intraepithelial lesions and Invasive cancer were recruited. The results of the study show that some of the risk factors associated with the cervical cancer get exaggerated when breast cancer cases were used as controls because risk factors of both cancers are opposite to each other. So it is concluded that in order to remove any bias, normal hospital controls or controls selected from multiple cancers should be taken to study the risk factors involved in cervical carcinogenesis.

A relationship between environmental degradation and mental health in rural Western Australia

Australia is currently experiencing a process of escalating ecosystem degradation. This landscape degradation is associated with many outcomes that may directly or indirectly impact on human health. This study used a Bayesian spatial method to examine the effects of environmental degradation (measured as dryland salinity) on the mental health of the resident rural population. An association was detected between dryland salinity and depression, indicating that environmental processes may be driving the degree of psychological ill-health in these populations.