Recent trends in racial and regional disparities in cervical cancer incidence and mortality in United States

Abstract

Background: Although black women experienced greater cervical cancer incidence and mortality rate reduction in recent years, they continue to have higher incidence rates than whites. Great variations also exist among geographic regions of the US, with the South having both the highest incidence and mortality rates compared to other regions. The present study explores the question of whether living in the South is associated with greater racial disparity in cervical cancer incidence and mortality by examining race- and region-specific rates and the trend between 2000 and 2012.

Methods: The Surveillance, Epidemiology, and End Results (SEER) 18 Program data was used. Cervical cancer incidence and mortality rates, annual percent changes, and disparity ratios were calculated using SEER*Stat software and Joinpoint regression for four groups: US14-Non-Hispanic White (NHW), US14-Non-Hispanic Black (NHB), South-NHW, and South-NHB, where South included 4 registries from Georgia and Louisiana and US14 were 14 US registries except the four South registries.

Results: The average age-adjusted cervical cancer incidence rate was the highest among South-NHBs (11.1) and mortality rate was the highest among US14-NHBs (5.4). In 2012, the degree of racial disparities between South-NHBs and South-NHWs was greater in terms of mortality rates (NHB:NHW = 1.80:1.35) than incidence rates (NHB:NHW = 1.45:1.15). While mortality disparity ratios decreased from 2000-2012 for US14-NHB (APC: -1.9(-2.3,-1.4), mortality disparity ratios for South-NHWs (although lower than NHBs) increased compared to US14-NHW. Incidence rates for NHBs continued to increase with increasing age, whereas rates for NHWs decreased after age 40. Mortality rates for NHBs dramatically increased at age 65 compared to a relatively stable trend for NHWs. The increasing racial disparity with increasing age in terms of cervical cancer incidence rates became more pronounced when corrected for hysterectomy prevalence.

Conclusions: Black race and South region were associated with higher cervical cancer incidence and mortality. Cervical cancer rates uncorrected for hysterectomy may underestimate regional and racial disparities. Increasing incidence rates for older NHBs compared to NHWs warrant further research to determine whether screening should continue for NHBs over age 65.

Fig 1. Cervical cancer incidence and mortality rates and disparity ratios by year, region, and race.

(A) Age-adjusted cervical cancer incidence rate of US14-NHW, US14-NHB, South-NHW, and South-NHB women by year of diagnosis. (B) Age-adjusted cervical cancer mortality rates of cervical cancer of US14-NHW, US14-NHB, South-NHW, and South-NHB women by year of diagnosis. (C) Incidence disparity ratios of US14-NHB, South-NHW, and South-NHB women by year of diagnosis with US14-NHW as reference group. (D) Mortality disparity ratios of US14-NHB, South-NHW, and South-NHB women by year of diagnosis with US14-NHW as reference group. Abbreviations: NHW–non-Hispanic white, NHB–non-Hispanic black, US14 –SEER18 registries excluding the 4 southern registries.

Fig 2

Trends of age-specific cervical cancer (A) incidence and (B) mortality disparity ratios by region between 2000 and 2012 for US14-NHW, US14-NHB, South-NHW, and South-NHB. Abbreviations: NHW–non-Hispanic white, NHB–non-Hispanic black, US14 –SEER18 registries excluding the 4 southern registries.

Fig 3. Age-specific cervical cancer incidence and mortality rates in the South by race (2008–2012).

Bar graphs represent incidences rates (gray for NHW and navy for NHB) and line graphs represent mortality rates (gray for NHW and navy for NHB).Abbreviations: NHW–non-Hispanic white, NHB–non-Hispanic black.

Fig 4. Age-specific cervical cancer incidence rates of black women pre- and post- US hysterectomy prevalence rate correction (2008–2012).

Abbreviations: NHB–non-Hispanic black.