Mitochondrial DNA Copy-Number Assessment Is a Potent Predictor for Prostate Cancer in White but Not Black Individuals

Area of Science:

• Genetics and Genomics
• Oncology
• Biochemistry

Background:

• Prostate cancer (PCa) disproportionately affects Black individuals.
• Mitochondrial DNA (mtDNA) copy number alterations are linked to mitochondrial dysfunction and cancer development.
• The role of mtDNA copy number in PCa, particularly across racial groups, remains under-explored.

Purpose of the Study:

• To investigate racial differences in circulating cell-free mtDNA and white blood cell (WBC) mtDNA copy number in patients with and without PCa.
• To determine if mtDNA copy number can serve as a predictive biomarker for PCa in a racially specific manner.

Main Methods:

• Measurement of plasma and WBC mtDNA copy number using droplet digital PCR (ddPCR) in 199 patients undergoing biopsy.
• Analysis of associations between mtDNA copy number and PCa status stratified by race using logistic regression.
• Comparison of the predictive accuracy of mtDNA copy number for PCa using Area Under the Curve (AUC) analysis.

Main Results:

• mtDNA copy number was significantly elevated in PCa cases versus controls in White patients, but not in Black patients.
• Black controls exhibited higher baseline mtDNA copy number than White controls.
• Plasma and WBC mtDNA copy number were significantly associated with PCa in White patients, but not Black patients, though plasma mtDNA showed potential for predicting PCa in Black men.

Conclusions:

• mtDNA copy number alterations are associated with PCa in White patients, but this association differs in Black patients.
• Disparities in baseline mtDNA copy number between racial groups may contribute to prostate cancer health disparities.
• mtDNA copy number holds potential as a PCa biomarker, with potential racial differences in its utility and implications for health equity.