Geography, Race, and Genetic Variation in Endometrial Cancer

A study done at SUNY Downstate Hospital recently found that black women of Caribbean descent with type I or type II endometrial cancer expressed significant differences in genetic variations when compared with a nationwide population of patients with endometrial cancer.

Albert Palileo, MD, a third-year gynecologic oncology fellow with SUNY Downstate Hospital, presented these research findings at the 2018 Society of Gynecologic Oncology Winter Meeting. IIn an interview with OncLive, a sister publication of Oncology Nursing News. Since we technically did not conduct the interview or do the original reporting

Palileo noted that while these results are not robust enough to guide treatment decisions, they may further contribute to a more personalized treatment approach.

“There does seem to be some molecular basis, some genetic basis, for why we see a difference in how our patients respond to treatment, how they present, and what cancers they ultimately end up getting,” he said. “So, we’re hoping this adds to the pool of molecular profiling data and ideally will contribute in the future to targeted therapies and advanced prognostic factors.”

SUNY Downstate is in a neighborhood in Brooklyn, New York with a high black Caribbean population; Palileo estimated that more than 90% of patients treated there fit that demographic. This group is not often included in clinical trials, so physicians at SUNY Downstate set out to evaluate what they had seen in practice.

“We’ve noticed anecdotally that they have different presentations in their cancers and different prognoses—they tend to present a bit more at a progressed level, but we wanted to put a number to it,” said Palileo.

Between 2015 and 2018, researchers collected 55 tissue samples with full profiling, including 24 type I samples and 31 type II. These samples were then analyzed using immunohistochemistry and next-generation sequencing of 165 genes at Caris Life Sciences. The results were then compared with 3133 endometrial cancer samples from a nationwide population collected by Caris.

“For the most common mutations we saw in our type I patients, PTEN was the most common at 56%, followed by BRCA2, PIK3CA, and some others like CTNNB1. In terms of our type II cancers, as expected, we saw P53, some mutations in FBXW7, and also PIK3,” Palileo said.

“Interestingly, when we compared [our data] to the national population, we found some clear differences. For example, in type II cancers, in nationwide data, BRCA mutations were about 17%, whereas in our population, we had no patients with BRCA mutations,” explained Palileo.

Expression of BRCA1 (13.6% vs 8.30%; P = .365), BRCA2 (45.50% vs 38.90%; P = .033), and ATM (8.70% vs 3.60%; P = .198) was higher among Caribbean patients with type I disease compared with the nationwide population. However, the opposite was true among patients with type II disease for BRCA1 (0% vs 10.8%; P = .053) and BRCA2 (0% vs 17.20%; P = .011). Expression of ATM remained higher among type II Caribbean patients versus the nationwide group (6.70% vs 2.20%; P = .12).

APC expression was lower among the Caribbean patients in the type I (17.40% vs 21.10%; P = .028) and type II groups (13.30% vs 2.90%; P = .001).

Expression of c-KIT was low for type II patients in both groups (Caribbean, 0%; nationwide, 0.50%; P =.696). Among type I patients, 8.70% of Caribbean patients were positive for c-KIT compared with 1.20% nationwide (P = .001).

Type I patients in the nationwide population were much more likely to be positive for TP53 (4.30% vs 23.70%; P = .03). TP53 expression was nearly identical in type II patients (67% vs 66.70%; P = .797).

Reference

Testani E, Chen M, Lee R, et al. Molecular profiling of endometrial carcinomas in a Caribbean black population [poster]. Presented at: 2018 SGO Annual Winter Meeting; February 8-10, 2018; Aspen, CO.