Aggressive endometrial cancer molecular subtypes, including presence of TP53 mutations and high mutant-allele tumor heterogeneity (MATH) score, are more common among African Americans compared with Caucasians, according to an analysis presented at the 2017 Society of Gynecologic Oncology Annual Meeting.1

The study evaluated data from the Cancer Genome Atlas research network of 337 patients with endometrial cancer. The cohort included 13.6% African American and 86.4% Caucasian patients. Statistical analyses included log rank testing and Cox modeling. Molecular subtypes included high copy number variant (CNV) for serous-like histology, low CNV for endometrioid-like histology, ultramutated polymerase ε, microsatellite instability hypermutated, mitotic immunoreactive and hormonal, cluster 4 somatic copy number alteration (SCNA), TP53 mutations, and MATH heterogeneity score.

Compared with the Caucasian cohort, African Americans were significantly more likely to have an integrative CNV-high subtype (24% vs 62%, respectively; P = .0005), mitotic subtype (34% vs 64%; P = .0006), cluster 4 SCNA (21% vs 57%; P < .0001), TP53 mutations (24% vs 56%; P = .002), and higher MATH score (P = .005).

Progression-free survival (PFS) was 2.4-fold lower in the African American compared with the Caucasian population (hazard ratio, 2.38; 95% CI, 1.23-4.62; P = .01), and the CNV high, mitotic, and cluster 4 SCNA subtypes, as well as presence of TP53 mutations and higher MATH score were associated with lower PFS.

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These results suggest that aggressive molecular subtypes of endometrial cancer are more common among the African American population, which may be a mechanism driving the lower PFS than that of the Caucasian population.

Reference

  1. Dubil EA, Tian C, Wang G, et al. Racial differences in molecular subtypes between black and white patients with endometrial cancer. Paper presented at: 48th Annual Meeting of the Society of Gynecologic Oncology; March 12-15, 2017; National Harbor, MD.