# Spillover effects of public school integration in the southern United States: diverging trends in statewide annual breast cancer incidence, 2001–2019

## TL;DR

This study finds that public school integration in Missouri was linked to lower breast cancer rates in Black women later in life, compared to those in South Carolina.

## Contribution

The study identifies long-term health spillover effects of public school integration on breast cancer incidence in Black women.

## Key findings

- NHB women in Missouri born 1944–1950 had significantly lower breast cancer incidence post-cutoff compared to NHW women in Missouri.
- NHB women in Missouri also had lower incidence than NHB women in South Carolina within the same birth cohort.
- No significant differences were found among women born 1937–1943 in either state.

## Abstract

Education has long been established as a key determinant of health, with prior research linking higher educational attainment to improved health outcomes and better self-management of chronic disease. This analysis investigated diverging trends in breast cancer incidence among cohorts of non-Hispanic Black (NHB) and non-Hispanic White (NHW) women of school age during public school integration in the southern United States following Brown v. Board of Education.

Using U.S. Cancer Statistics data from 2001 to 2019, I conducted several segmented linear regressions comparing trends in annual breast cancer incidence among women in Missouri and South Carolina born between 1937 and 1950, as these two states’ responses to Brown v. Board starkly contrasted one another. I hypothesized that, given Missouri’s swift integration of public schools in 1955—versus South Carolina’s continued resistance to integration through 1970—I’d observe significant changes in trend after age 62, the median age of breast cancer diagnosis, among NHB women in Missouri born from 1944 to 1950.

Among NHB women in Missouri born from 1944 to 1950, I observed a significant reduction in breast cancer incidence post-cutoff relative to NHW women in Missouri (p < 0.001) and NHB women in South Carolina (p = 0.017) within the same birth cohort. In both states, I observed no significant differences in incidence among NHB and NHW women born from 1937 to 1943.

Public school integration appears to have been associated with long-term protective spillover effects against breast cancer among younger Black students in Missouri, underscoring the importance of, and continued need for, policies that combat lingering de facto school segregation.