Influence of socioeconomic factors on survival after breast cancer—A nationwide cohort study of women diagnosed with breast cancer in Denmark 1983–1999

Abstract

The reasons for social inequality in breast cancer survival are far from established. Our study aims to study the importance of a range of socioeconomic factors and comorbid disorders on survival after breast cancer surgery in Denmark where the health care system is tax-funded and uniform. All 25,897 Danish women who underwent protocol-based treatment for breast cancer in 1983-1999 were identified in a clinical database and information on socioeconomic variables and both somatic and psychiatric comorbid disorders was obtained from population-based registries. We used Cox proportional hazards models to estimate the association between socioeconomic position and overall survival and further to analyse breast cancer specific deaths in a competing risk set-up regarding all other causes of death as competing risks. The adjusted hazard ratio (HR) for death was reduced in women with higher education (HR, 0.91; 95% confidence interval (CI), 0.85-0.98), with higher income (HR, 0.93; 95% CI, 0.87-0.98) and with larger dwellings (HR, 0.90; 95% CI, 0.85-0.96 for women living in houses larger than 150 m 2 ). Presence of comorbid disorders increased the HR. An interaction between income and comorbid disorders resulting in a 15% lower survival 10 year after primary surgery in poor women with low-risk breast cancer having comorbid conditions (65%) compared to rich women with similar breast cancer prognosis and comorbid conditions (80%) suggests that part of the explanation for the social inequality in survival after breast cancer surgery in Denmark lies in the access to and/or compliance with management of comorbid conditions in poorer women. ' 2007 Wiley-Liss, Inc.Key words: breast cancer; survival; socioeconomic position; register-based; comorbidity Overall survival of breast cancer patients has improved but unfortunately not all groups of women share these benefits equally. Although affluent women have a higher incidence of breast cancer than socially deprived women, several studies, using individual and area-based socioeconomic measures, have shown consistently that deprived women with breast cancer have poorer survival.1-13 Social inequalities in survival may involve differences in the timing of diagnosis, in the biological characteristics of the tumour, in treatments applied or in patient-specific factors, such as psychosocial factors or presence of comorbid conditions.14,15 Comorbidity in breast cancer patients limits treatment options, increases the risk of death from other causes, 16,17 and adversely affects survival. 16,18 However, the extent to which socioeconomic differences in comorbidity explain disparities in survival of breast cancer is not clear.In an earlier study, among postmenopausal Danish women, we observed, an independent effect of education, disposable income and living in rural areas on the risk of being diagnosed with a high risk breast cancer (as defined by tumour size > 20 mm, 1 or more tumour positive axillary lymph nodes, ductal tumour with grade of malignancy II or III and receptor negative statu...

Education as a predictor of quality of life outcomes among disadvantaged men

“…Other studies have also observed an association between poor HRQOL outcomes and low socioeconomic status. 30 Previous studies have also examined the influence of socioeconomic status on HRQOL in men with prostate cancer and found an inverse association between low socioeconomic status and comorbidity, sexual and urinary function and other HRQOL outcomes. 31 Very few studies have examined the relationship between education level and HRQOL in men with prostate cancer.…”

Comorbidities and Their Management: Potential Impact on Breast Cancer Outcomes

“…These fi ndings reported in the 2014 Annual Report to the Nation on the Status of Cancer (Edwards et al 2013 ) underscore previous fi ndings that breast cancer patients with one or more comorbidities are at substantially increased risk of death from competing causes and at modestly increased risk of breast cancer specifi c death (Sogaard et al 2013 ;Patnaik et al 2011b ;Land et al 2012a , b ;Berglund et al 2012 ;Bush et al 2011 ), and that breast cancer survivors who are most likely to be impacted by comorbidities are women with early stage breast cancer who have high other cause mortality, who have shown little or modest improvements in breast cancer specifi c mortality over time (Edwards et al 2013 ;Cronin-Fenton et al 2007 ;Land et al 2012a ;Izano et al 2014 ). Findings from over 15 retrospective cohort studies (Cronin-Fenton et al 2007 ;Tammemagi et al 2005 ;Yancik et al 2001a ;Schonberg et al 2010 ;Carlsen et al 2008 ;Dalton et al 2007 ;JanssenHeijnen et al 2005 ;Louwman et al 2005, Houterman et al 2004Nagel et al 2004 ;Maskarinec et al 2003 ;Du et al 2008 ;Harris et al 2008 ;McPherson et al 2002 ;Siegelmann-Danieli et al 2006 ) suggest that comorbidity increases risk of competing cause mortality by up to sixfold, while breast cancer specifi c mortality is increased by 20-50 % (Patnaik et al 2011a ;Berglund et al 2012 ;Schonberg et al 2010 ;Dalton et al 2007 ;Du et al 2008 ), although some studies have failed to observe differences in breast cancer recurrence or survival (Tammemagi et al 2005 ;Braithwaite et al 2012 ;…”

Are different groups of cancer patients offered rehabilitation to the same extent? A report from the population-based study “The Cancer Patient’s World”

“…In Denmark, the publicly paid health care system is supposed to ensure equal access to health care services regardless of socioeconomic status or employment. However, social inequality in survival after cancer has been shown in several countries [24][25][26][27], including Denmark [28,29].…”