Difference of stage at cancer diagnosis by socioeconomic status for four target cancers of the National Cancer Screening Program in Korea: Results from the Gwangju and Jeonnam cancer registries

Abstract

BackgroundThe aim of this study was to evaluate whether stage at cancer diagnosis differed according to patient economic status.MethodsA total of 10,528 patients with cancer of the stomach, colorectum, breast, or cervix, which are target organs of the Korean National Cancer Screening Program (NCSP; fully implemented in 2005) were extracted from population-based cancer registries. The patients were classified into four groups based on socioeconomic status (SES), as determined using their National Health Insurance (NHI) monthly premium at the time of cancer diagnosis. Cancer stage at diagnosis was defined as early (in situ/local) or late stage (regional/distant) based on the Surveillance, Epidemiology, and End Results (SEER) summary stage. Multivariable logistic regression analysis was performed to estimate the risk of non-local stage using age, residential area, and community deprivation index as covariates.ResultsThe lowest SES subjects showed significantly higher risks of being diagnosed at a later stage for stomach, colorectal, and female breast cancer, but not for cervical cancer, compared with the highest SES subjects. The estimated ORs were 1.28 (95% CI, 1.10–1.49), 1.29 (95% CI, 1.03–1.61), and 1.35 (95% CI, 1.02–1.81) in the lowest SES subjects with stomach, colorectal, and breast cancer, respectively.ConclusionsIn conclusion, later stage diagnoses of stomach, colon, and female breast cancer are still associated with SES in Korea in the era of the NCSP for the lower SES population.

Socioeconomic and demographic inequalities in stage at diagnosis and survival among colorectal cancer patients: evidence from a Swiss population‐based study

“…Studies conducted in other developed countries have reported socioeconomic inequalities in CRC stage at diagnosis [10][11][12] and survival [11,[18][19][20]. However, social disparities were not observed for all regions or countries and for all time periods investigated [34,35].…”

Occupational Class and Cancer Survival in Korean Men: Follow-Up Study of Nation-Wide Working Population

“…Although lack of income is not a barrier for receiving screening, nevertheless, it has been shown that low income groups are less likely to participate in the national screening program [16]. As a result of the low participation rates, individuals in the bottom quartile of income have been shown to have a roughly 1.3 times higher risk of being diagnosed with stomach and colorectal cancer at an advanced stage [17]. Besides the national screening program, private cancer screening with extra payment is widely available throughout Korea.…”

Occupational inequalities in female cancer incidence in Japan: Hospital-based matched case-control study with occupational class

“…However, for prevention, the SES gap for cancer screening may exist because municipalities provide cancer screening for homemakers and workers in small companies; health insurance groups at workplaces provide screening for workers in large industries ( Tanaka et al, 2017 , Ikeda et al, 2011 ). The proportion of individuals undergoing cancer screening is greater in the latter category; people with higher SES tend to undergo regular cancer screening ( Chor et al, 2014 ; Ikeda et al, 2011 ; Kweon, Kim, Kang, Shin, & Choi, 2017 ). Indeed, in the present study, the odds for homemakers (adjusted OR 0.80) were weaker than subjects with higher SES (adjusted OR 0.67 for managers in blue-collar industries).…”

“…This finding suggests that homemakers may have limited access to resources to promote their health (e.g., breast cancer screening) ( Zaitsu et al, 2018 ); alternatively, homemakers may have working stress to a lesser extent at home, their main workplace. Additionally, the likelihood of undergoing breast cancer screening may be higher in individuals with higher SES, which is associated with overdiagnosis ( Chor et al, 2014 , Kweon et al, 2017 , Jacklyn et al, 2016 ). With potential mediation through sleep disturbance and telomere shortening, breast cancer risk may be associated with night shift workers, such as nurses ( Samulin Erdem et al, 2017 , Yuan et al, 2018 ).…”