Early detection of breast cancer rectifies inequality of breast cancer outcomes

Objectives To explain apparent differences among mammography screening services in Sweden using individual data on participation in screening and with breast cancer–specific survival as an outcome. Methods We analysed breast cancer survival data from the Swedish Cancer Register on breast cancer cases from nine Swedish counties diagnosed in women eligible for screening. Data were available on 38,278 breast cancers diagnosed and 4312 breast cancer deaths. Survival to death from breast cancer was estimated using the Kaplan–Meier estimate, for all cases in each county, and separately for cases of women participating and not participating in their last invitation to screening. Formal statistical comparisons of survival were made using proportional hazards regression. Results All counties showed a reduction in the hazard of breast cancer death with participation in screening, but the reductions for individual counties varied substantially, ranging from 51% (95% confidence interval 46–55%) to 81% (95% confidence interval 74–85%). Survival rates in nonparticipating women ranged from 53% (95% confidence interval 40–65%) to 74% (95% confidence interval 72–77%), while the corresponding survival in women participating in screening varied from 80% (95% confidence interval 77–84%) to 86% (95% confidence interval 83–88%), a considerably narrower range. Conclusions Differences among counties in the effect of screening on breast cancer outcomes were mainly due to variation in survival in women not participating in screening. Screening conferred similarly high survival rates in all counties. This indicates that the performance of screening services was similar across counties and that detection and treatment of breast cancer in early-stage reduces inequalities in breast cancer outcome.

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Trends in breast cancer survival by race-ethnicity in Florida.

Journal of Clinical Oncology ◽

10.1200/jco.2021.39.15_suppl.e18556 ◽

2021 ◽

Vol 39 (15_suppl) ◽

pp. e18556-e18556

Author(s):

Robert Brooks Hines ◽

Asal Johnson ◽

Eunkyung Lee ◽

Stephanie Erickson ◽

Saleh M.M. Rahman

Keyword(s):

Breast Cancer ◽

Ethnic Disparities ◽

Cancer Death ◽

Cancer Outcomes ◽

Subdistribution Hazard ◽

Breast Cancer Death ◽

Breast Cancer Outcomes ◽

Race Ethnicity ◽

Racial Ethnic ◽

Hispanic White

e18556 Background: Considerable efforts to improve disparities in breast cancer outcomes for underserved women have occurred over the past 3 decades. This study was conducted to evaluate trends in survival, by race-ethnicity, for women diagnosed with breast cancer in Florida over a 26-year period to assess potential improvement in racial-ethnic disparities. Methods: This was a retrospective cohort study of women diagnosed with invasive breast cancer in Florida between 1990-2015. Data were obtained from the Florida Cancer Data System. Women in the study were categorized according to race (white/black) and Hispanic ethnicity (yes/no) as non-Hispanic white (NHW), non-Hispanic black (NHB), Hispanic white (HW), and Hispanic black (HB). Cumulative incidence estimates of 5- and 10-year breast cancer death with 95% confidence intervals (CI) were obtained by race-ethnicity, according to diagnosis year. Subdistribution hazard models were used to obtain subdistribution hazard ratios (sHR) for the relative rate of breast cancer death accounting for competing causes. Results: Compared to NHW women, minority women were more likely to be younger, be uninsured or have Medicaid as health insurance, live in high poverty neighborhoods, have more advanced disease at diagnosis, have high grade tumors, have hormone receptor negative tumors, and receive chemotherapy as treatment. Minority women were less likely to receive surgery. Over the course of the study, breast cancer mortality decreased for all racial-ethnic groups, and racial-ethnic minorities had greater absolute and relative improvement in breast cancer survival for nearly all metrics compared to non-Hispanic white (NHW) women. However, for the most recent time period (2010-2015), black women still experienced significant survival disparities with non-Hispanic black (NHB) women having twice the rate of 5-year (sHR = 2.04: 95% CI; 1.91-2.19) and 10-year (sHR = 2.02: 95% CI; 1.89-2.16) breast cancer death. Conclusions: Despite efforts to improve disparities in breast cancer outcomes for underserved women in Florida, additional targeted approaches are needed to reduce the poorer survival in black (especially NHB) women. Our next step is to conduct a mediation analysis of the most important factors driving racial/ethnic disparities in breast cancer outcomes for women in Florida.

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