ABSTRACT
PURPOSE: Black women experience the highest breast cancer mortality rate compared with women of other racial/ethnic groups. To gain a deeper understanding of breast cancer heterogeneity across diverse populations, we examined a VEGF-hypoxia gene expression signature in breast tumors from women of diverse ancestry. EXPERIMENTAL DESIGN: We developed a NanoString nCounter gene expression panel and applied it to breast tumors from Nigeria (n = 182) and the University of Chicago (Chicago, IL; n = 161). We also analyzed RNA sequencing data from Nigeria (n = 84) and The Cancer Genome Atlas (TCGA) datasets (n = 863). Patient prognosis was analyzed using multiple datasets. RESULTS: The VEGF-hypoxia signature was highest in the basal-like subtype compared with other subtypes, with greater expression in Black women compared with White women. In TCGA dataset, necrotic breast tumors had higher scores for the VEGF-hypoxia signature compared with non-necrosis tumors (P < 0.001), with the highest proportion in the basal-like subtype. Furthermore, necrotic breast tumors have higher scores for the proliferation signature, suggesting an interaction between the VEGF-hypoxia signature, proliferation, and necrosis. T-cell gene expression signatures also correlated with the VEGF-hypoxia signature when testing all tumors in TCGA dataset. Finally, we found a significant association of the VEGF-hypoxia profile with poor outcomes when using all patients in the METABRIC (P < 0.0001) and SCAN-B datasets (P = 0.002). CONCLUSIONS: These data provide further evidence for breast cancer heterogeneity across diverse populations and molecular subtypes. Interventions selectively targeting VEGF-hypoxia and the immune microenvironment have the potential to improve overall survival in aggressive breast cancers that disproportionately impact Black women in the African Diaspora.
Subject(s)
Breast Neoplasms , Gene Expression Regulation, Neoplastic , Vascular Endothelial Growth Factor A , Humans , Female , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Breast Neoplasms/mortality , Breast Neoplasms/metabolism , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/metabolism , Prognosis , Middle Aged , Biomarkers, Tumor/genetics , Gene Expression Profiling , Black People/genetics , Transcriptome , Adult , Aged , Hypoxia/genetics , Tumor Microenvironment/genetics , Up-RegulationABSTRACT
Objective: Adjuvant radiation therapy (ART) is often recommended for high-risk cSCC patients but carries significant costs and risks. This study aims to determine if utilizing the 40-GEP test to guide ART can reduce healthcare costs in cSCC management. Methods: Medical claims data with new diagnoses of cSCC for the 12 months ending June 2022 in the Medicare (≥65 years) population (source: IQVIA claims database) were obtained and normalized to the general population for missingness. CPT codes associated with radiation therapy within one-year post diagnosis were used to establish adjuvant RT use (defined as 'ART'). Average weighted direct costs for four major ART modalities were calculated from published studies and (IQVIA). Sensitivity analysis was used to assess the financial impact of ART treatment using varying distributions of 40-GEP Class results. Results: Normalized medical claims data identified 22,917 Medicare-eligible cSCC patients who received ART within the United States. The weighted average direct cost for ART, which includes the four most used CPT code-defined modalities (IGRT, IMRT, IMPT, and XRT), was $60,693 per patient, amounting to an annual projected ART cost of $1.4 billion. Using the distribution of 40-GEP results from published studies, utilization of a 40-GEP test result to avoid ART in these patients could save up to $972 million in Medicare-eligible population. Sensitivity analysis shows, depending upon the distribution of the 40-GEP results, that for every 10% of Class 2A test results omitting ART, an extra $38-66 million in annual savings is expected. Limitations: Potential limitations include a need for more comprehensive patient information and the cost of ART-related complications. Conclusion: Utilizing the 40-GEP test results to guide ART decision-making would result in material savings to Medicare.