A Contemporary Analysis of Racial and Ethnic Disparities in Diagnosis of Early-Stage Breast Cancer and Stage-Specific Survival by Molecular Subtype

Racial/Ethnic Differences in Pathologic Complete Response to Neoadjuvant Chemotherapy and Survival Among Early-Stage, Erb-B2 Receptor Tyrosine Kinase 2-Low Breast Cancer Patients

Racial/ethnic differences in pathologic complete response (pCR), and in overall survival (OS) by pCR status, among early-stage, erb-b2 receptor tyrosine kinase 2 (ERBB2)-low breast cancer patients after neoadjuvant chemotherapy (NACT) are unknown. Data were from the 2010-2020 National Cancer Database that included Asian/Pacific Islander (API), American Indian/Alaska Native/Other (AIANO), Black, Hispanic, and White patients. pCR and OS were modeled using logistic regression and Cox regression, respectively. Of 25,577 patients, Black patients achieved a 17.4% pCR rate, Hispanic 16.0%, White 14.7%, API 13.5%, and AIANO 10.9%. AIANO patients had lower odds of pCR than White patients (adjusted odds ratio, 0.66; 95% confidence interval [CI], 0.48-0.91). Among patients without pCR, API (adjusted hazard ratio [aHR], 0.62; 95% CI, 0.51-0.76) and Hispanic (aHR, 0.77; 95% CI, 0.67-0.89) patients had lower mortality risks than White patients. Among patients with pCR, similar OS rates were observed between Hispanic (aHR, 1.08; 95% CI, 0.66-1.78), Black (aHR, 0.77; 95% CI, 0.55-1.09), API (aHR, 0.41; 95% CI, 0.15-1.12), or AIANO (aHR, 0.35; 95% CI, 0.05-2.50) and White patients. Post-NACT pCR rates were similar across racial/ethnic groups of early-stage, ERBB2-low breast cancer patients. Among patients without pCR, API and Hispanic patients had better OS; among patients with pCR, there was no differential OS by race/ethnicity. Our findings suggest the need for longitudinal studies of OS differences in this patient population.

Disparities in Late-Stage Breast and Colorectal Cancer Diagnosis Among Hispanic, Non-Hispanic White, and Non-Hispanic Black Patients: a Retrospective Cohort Study of Texas Medicare Beneficiaries

BACKGROUND

Disparities in late-stage breast or colorectal cancer diagnosis in younger populations are associated with social determinants of health (SDOH; education, poverty, housing, employment). We hypothesized that, in older Medicare beneficiaries, disparities in late-stage cancer diagnosis between Hispanic, non-Hispanic Black (NHB), and non-Hispanic White (NHW) patients would be associated with SDOH, comorbidities, and primary care physician (PCP) access.

METHODS

We analyzed 2005-2017 Texas Cancer Registry data linked with Medicare data for patients aged ≥ 66 (n = 86,501). Variables included age at diagnosis, sex, comorbidities, poverty level, education, PCP, and relevant cancer screening within 1 year.

RESULTS

For breast cancer in women (Hispanic, n = 6380; NHW, n = 39,225; NHB, n = 4055), a fully adjusted model showed significantly higher odds of late-stage cancer diagnosis only in NHB patients (odds ratio [OR] 1.11, 95% confidence interval [CI] 1.01-1.22) compared with NHW; adjustment for comorbidities and SDOH partially decreased the odds of late-stage diagnosis relative to NHWs. Interaction terms between race-ethnicity and poverty were not significant. For colorectal cancer, a fully adjusted multivariate model showed significantly higher odds of late-stage diagnosis only among NHBs (n = 3318, OR 1.29, 95% CI 1.19-1.40) relative to NHWs (n = 27,470); adjustment for SDOH partially decreased the odds of late-stage diagnosis in NHB patients. Interaction terms between race-ethnicity and poverty were not significant.

CONCLUSION

Racial disparities in late-stage breast and colorectal cancer diagnoses remain after adjustment for SDOH and clinically relevant factors, underscoring the need to optimize access to screening and timely cancer treatment in racial/ethnic minorities.

Profiling the Somatic Mutational Landscape of Breast Tumors from Hispanic/Latina Women Reveals Conserved and Unique Characteristics

Somatic mutational profiling is increasingly being used to identify potential targets for breast cancer. However, limited tumor-sequencing data from Hispanic/Latinas (H/L) are available to guide treatment. To address this gap, we performed whole-exome sequencing (WES) and RNA sequencing on 146 tumors and WES of matched germline DNA from 140 H/L women in California. Tumor intrinsic subtype, somatic mutations, copy-number alterations, and expression profiles of the tumors were characterized and compared with data from tumors of non-Hispanic White (White) women in The Cancer Genome Atlas (TCGA). Eight genes were significantly mutated in the H/L tumors including PIK3CA, TP53, GATA3, MAP3K1, CDH1, CBFB, PTEN, and RUNX1; the prevalence of mutations in these genes was similar to that observed in White women in TCGA. Four previously reported Catalogue of Somatic Mutations in Cancer (COSMIC) mutation signatures (1, 2, 3, 13) were found in the H/L dataset, along with signature 16 that has not been previously reported in other breast cancer datasets. Recurrent amplifications were observed in breast cancer drivers including MYC, FGFR1, CCND1, and ERBB2, as well as a recurrent amplification in 17q11.2 associated with high KIAA0100 gene expression that has been implicated in breast cancer aggressiveness. In conclusion, this study identified a higher prevalence of COSMIC signature 16 and a recurrent copy-number amplification affecting expression of KIAA0100 in breast tumors from H/L compared with White women. These results highlight the necessity of studying underrepresented populations.

SIGNIFICANCE

Comprehensive characterization of genomic and transcriptomic alterations in breast tumors from Hispanic/Latina patients reveals distinct genetic alterations and signatures, demonstrating the importance of inclusive studies to ensure equitable care for patients. See related commentary by Schmit et al., p. 2443.

Health insurance and neighborhood poverty as mediators of racial disparities in advanced disease stage at diagnosis and nonreceipt of surgery for women with breast cancer

BACKGROUND

In our recent study, advanced disease stage and nonreceipt of surgery were the most important mediators of the racial disparity in breast cancer survival. The purpose of this study was to quantify the racial disparity in these two intermediate outcomes and investigate mediation by the more proximal mediators of insurance status and neighborhood poverty.

METHODS

This was a cross-sectional study of non-Hispanic Black and non-Hispanic White women diagnosed with first primary invasive breast cancer in Florida between 2004 and 2015. Log-binomial regression was used to obtain prevalence ratios (PR) with 95% confidence intervals (CIs). Multiple mediation analysis was used to assess the role of having Medicaid/being uninsured and living in high-poverty neighborhoods on the race effect.

RESULTS

There were 101,872 women in the study (87.0% White, 13.0% Black). Black women were 55% more likely to be diagnosed with advanced disease stage at diagnosis (PR, 1.55; 95% CI, 1.50-1.60) and nearly twofold more likely to not receive surgery (PR, 1.97; 95% CI, 1.90-2.04). Insurance status and neighborhood poverty explained 17.6% and 5.3% of the racial disparity in advanced disease stage at diagnosis, respectively; 64.3% remained unexplained. For nonreceipt of surgery, insurance status explained 6.8% while neighborhood poverty explained 3.2%; 52.1% was unexplained.

CONCLUSIONS

Insurance status and neighborhood poverty were significant mediators of the racial disparity in advanced disease stage at diagnosis with a smaller impact on nonreceipt of surgery. However, interventions designed to improve breast cancer screening and receipt of high-quality cancer treatment must address additional barriers for Black women with breast cancer.

Disparities in Survival Outcomes among Racial/Ethnic Minorities with Head and Neck Squamous Cell Cancer in the United States

Background: Racial/ethnic (R/E) minorities with head and neck squamous cell carcinoma (HNSCC) have worse survival outcomes compared to White patients. While disparities in patient outcomes for R/E minorities have been well documented, the specific drivers of the inferior outcomes remain poorly understood. Patients and Methods: This was a population-based retrospective cohort study that analyzed HNSCC patients using the National Cancer Database (NCDB) from 2000–2016. Patient outcomes were stratified by R/E groups including White, Black, Hispanic, Native American/Other, and Asian. The main outcome in this study was overall survival (OS). Univariate time-to-event survival analyses were performed using the Kaplan–Meier product limit estimates and the log-rank test to evaluate the differences between strata. Results: There were 304,138 patients with HNSCC identified in this study, of which 262,762 (86.3%) were White, 32,528 (10.6%) were Black, 6191 were Asian (2.0%), and 2657 were Native American/Other (0.9%). Black R/E minorities were more likely to be uninsured (9% vs. 5%, p < 0.0001), have Medicaid insurance (22% vs. 8%, p < 0.0001), be in a lower income quartile (<30,000, 42% vs. 13%, p < 0.0001), have metastatic disease (5% vs. 2%, p < 0.001), and have a total treatment time 6 days longer than White patients (median 107 vs. 101 days, p < 0.001). The 5-year OS for White, Black, Native American/Other, and Asian patients was 50.8%, 38.6%, 51.1%, and 55.8%, respectively. Among the oropharynx HNSCC patients, the 5-year OS rates in p16+ White, Black, and Asian patients were 65.7%, 39.4%%, and 55%, respectively. After a multivariate analysis, Black race was still associated with an inferior OS (HR:1.09, 95% CI: 1.03–1.15, p = 0.002). Conclusions: This large cohort study of HNSCC patients demonstrates that Black race is independently associated with worse OS, in part due to socioeconomic, clinical, and treatment-related factors.