Molecular Subtypes of High-Grade Serous Ovarian Cancer across Racial Groups and Gene Expression Platforms

Area of Science:

• Genomics
• Oncology
• Racial Disparities in Health

Background:

• High-grade serous carcinoma (HGSC) gene expression subtypes are linked to different survival outcomes.
• Investigated HGSC gene expression in Black individuals to determine if racial differences contribute to survival disparities.
• Examined whether gene expression variations by self-identified race impact HGSC survival rates between Black and White individuals.

Purpose of the Study:

• To characterize HGSC gene expression subtypes in Black individuals.
• To compare HGSC gene expression and survival patterns between Black and White populations.
• To assess the consistency of HGSC subtype assignment across different racial groups and platforms.

Main Methods:

• Utilized K-means clustering on RNA sequencing and genotyping data from Black, White, and Japanese individuals.
• Summarized gene expression patterns using moderated t-scores and compared them across datasets.
• Employed Cox proportional hazards models to analyze subtype-specific survival, mapping to The Cancer Genome Atlas (TCGA) subtypes.

Main Results:

• Gene expression patterns were consistent across platforms and racial groups.
• The immunoreactive subtype was more prevalent in Black individuals (39%) compared to White and Japanese individuals (23%-28%).
• Subtype-specific survival patterns were similar between Black and White populations, with no significant differences in risk of death across subtypes.

Conclusions:

• While the prevalence of HGSC subtypes differs by race, their impact on survival is consistent.
• HGSC subtypes can be reliably assigned across various platforms and self-identified racial groups.
• Racial differences in HGSC subtype prevalence do not appear to drive survival disparities.