Social class is an important and independent prognostic factor of breast cancer mortality

Abstract

Reasons of the important impact of socioeconomic status on breast cancer prognosis are far from established. This study aims to evaluate and explain the social disparities in breast cancer survival in the Swiss canton of Geneva, where healthcare costs and life expectancy are among the highest in the world. This populationbased study included all 3,920 female residents of Geneva, who were diagnosed with invasive breast cancer before the age of 70 years between 1980 and 2000. Patients were divided into 4 socioeconomic groups, according to the woman's last occupation. We used Cox multivariate regression analysis to identify reasons for the socioeconomic inequalities in breast cancer survival. Compared to patients of high social class, those of low social class had an increased risk (unadjusted hazard ratio [HR] 2.4, 95% CI: 1.6-3.5) of dying as a result of breast cancer. These women were more often foreigners, less frequently had screen-detected cancer and were at more advanced stage at diagnosis. They less frequently underwent breast-conserving surgery, hormonal therapy, and chemotherapy, in particular, in case of axillary lymph node involvement. When adjusting for all these factors, patients of low social class still had a significantly increased risk of dying of breast cancer (HR 1.8, 95% CI: 1.2-2.6). Overmortality linked to low SES is only partly explained by delayed diagnosis, unfavorable tumor characteristics and suboptimal treatments. Other factors, not measured in this study, also could play a role. While waiting for the outcome of other researches, we should consider socioeconomic status as an independent prognostic factor and provide intensified support and surveillance to women of low social class. ' 2006 Wiley-Liss, Inc.Key words: breast carcinoma; socioeconomic status; incidence; mortality; survivalIn North America and Western Europe, breast cancer accounts for more than 30% of new cancer cases and for 25% of cancer deaths among women. Breast cancer mortality rates are now decreasing because of the widely generalized use of mammography screening and the improvement in treatment. 1 Besides stage, tumor characteristics and treatment, only few factors are recognized as independent prognostic factors. Socioeconomic status (SES) could be one of them.Breast cancer occurs more frequently in wealthy countries 2 and among women with high SES. 3 This is partly due to a higher prevalence of breast cancer risk factors, such as older age at first pregnancy, low parity, high-calorie intake, sedentary occupation and use of hormonal replacement therapy in women with high SES. [3][4][5] On the other hand, breast cancer survival is in general lower in less affluent countries 6 and in women with low income or educational level. 3

Impact of socioeconomic status on prostate cancer diagnosis, treatment, and prognosis

“…1,2 This association has been established for several other cancer sites, such as the breast, cervix, colon, etc. [3][4][5][6] SES plays an important role in prostate cancer. Higher SES has been associated with more frequent PSA screening, 7,8 a lower stage of disease at diagnosis, and better tumor differentiation.…”

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

“…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][2][3][4][5][6][7][8][9][10][11][12][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.…”

Breast Cancer Mortality In Brazil: Correlation With Human Development Index

“…In the study by Bouchardy et al [30], when comparing patients of various social classes, those of low social class, showed an increased risk of dying as a result of breast cancer (HR 2.4, 95% CI: 1.6 -3.5), even after adjusting for conservative surgery, radiotherapy, chemotherapy and lymph involvement (HR 1.8 , IC 95%: 1.2 -2.6).…”