Breast cancer survival disparity between African American and Caucasian women in Arkansas: A race-by-grade analysis

Differences in Breast Cancer Presentation at Time of Diagnosis for Black and White Women in High Resource Settings

This paper provides a narrative review of the existing literature on differences in demographic and biological features of breast cancer at time of diagnosis between Black and White women in Canada, the United Kingdom and the United States. Electronic database searches for published peer-reviewed articles on this topic were conducted, and 78 articles were included in the final narrative review. Differences between Black and White women were compared for eight categories including age, tumour stage, size, grade, lymph node involvement, and hormone status. Black women were significantly more likely to present with less favourable tumour features at the time of diagnosis than White women. Significant differences were reported in age at diagnosis, tumour stage, size, grade and hormone status, particularly triple negative breast cancer. Limitations on the generalizability of the review findings are discussed, as well as the implications of these findings on future research, especially within the Canadian context.

The combined survival effect of codon 72 polymorphisms and p53 somatic mutations in breast cancer depends on race and molecular subtype

Background

The codon 72 polymorphism in the p53 gene relates to the risk of breast cancer (BC), but this relationship in racially diverse populations is not known. The present study examined the prognostic value of this polymorphism for African American (AA) and Caucasian (CA) BC patients separately and considered the confounding variables of molecular subtypes and somatic mutations in p53.

Methods

Tissue sections of BCs from 116 AAs and 160 CAs were evaluated for p53 mutations and genotyped for the codon 72 polymorphism. The relationships of phenotypes to clinicopathologic features were determined by χ2 analyses; patient survival was estimated by Kaplan-Meier univariate and Cox regression multivariate models in a retrospective cohort study design.

Results

The proportion of single nucleotide polymorphism (SNP) 72 alleles differed for races. Many cancers of AAs were Pro/Pro, but most for CAs were Arg/Arg. A higher frequency of missense p53 mutations was evident for AAs. There was an interaction between the SNP allele and p53 mutations for AA women only. The proportion of women with both the Pro/Pro allele and a p53 somatic mutation was higher for AA than CA women. The interaction between missense p53 mutations and Pro/Pro had a negative effect on survival, particularly for AAs with luminal cancers.

Conclusions

For BCs, the survival effect of SNP72 combined with a p53 missense mutation is dependent on race and molecular subtype. Although such a mutation is a marker of poor prognosis, it is relevant to identify the variant Pro/Pro in the case of AAs, especially those with luminal subtypes of BC.

Sequential matched analysis of racial disparities in breast cancer hospitalization outcomes among African American and White patients

BACKGROUND

The purpose of this study is to determine if racial disparities in inpatient outcomes persist among hospitalized patients comparing African American and White breast cancer patients matched on demographics, presentation and treatment.

METHODS

A total of 136,211 African American and White breast cancer patients from the Healthcare Cost and Utilization Project - Nationwide Inpatient Sample (HCUP-NIS) database, matched on demographics alone, demographics and presentation or demographics, presentation and treatment were studied. Conditional logistic regression was conducted to evaluate post-surgical complications, length of stay and in-hospital mortality outcomes. Analysis was further stratified by age (≤65 years and >65years) to evaluate whether disparities were larger in younger or older patients. All analysis was conducted using SAS 9.3.

RESULTS

White women had significantly shorter hospital length of stay when matched on demographics (β=-0.87, p-value=<0.0001), demographics and presentation (β=-0.63, p-value=<0.0001), and demographics, presentation and treatment (β=-0.51, p-value=<0.0001) compared with African Americans. White women also had lower odds of mortality compared with African American women when matched on demographics (OR: 0.72, 95% CI: 0.65-0.79), demographics and presentation (OR: 0.77, 95% CI: 0.71-0.85), or matched on demographics, presentation and treatment (OR: 0.80, 95% CI: 0.73-0.88). The racial difference observed in length of stay and mortality was larger in the age group ≤65 years compared with >65years CONCLUSION: African American women experienced higher odds of inpatient mortality and longer length of stay compared with White women even after accounting for differences in demographics, presentation and treatment characteristics.