Somatic genomic landscape of prostate adenocarcinoma at a comprehensive cancer center in New Mexico: A retrospective study (2015-2022).
Authors: Abdelsamia Mahmoud , Chavarin Daniel Joseph , Coy Jonathan , Pankratz V. Shane , Tawfik Bernard , Hashemi-Sadraei Neda , Khatib Jude 
Published: February 2025

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Background:
Prostate cancer is the second leading cause of cancer-related deaths in men. In New Mexico, it is the leading cause of cancer death among specific populations, particularly American Indians and African Americans. This study investigates the frequency and diversity of somatic mutations in patients with prostate adenocarcinoma treated at the University of New Mexico Comprehensive Cancer Center (UNMCCC).
Methods:
We conducted a retrospective analysis of patients with prostate adenocarcinoma treated at UNMCCC from 2015 to 2022 who underwent screening for somatic mutations via next-generation sequencing (NGS). We evaluated these mutations and collected data on tissue type tested, race, ethnicity, and age. Descriptive analysis summarized frequencies of somatic mutations overall and across ethnic groups. Due to small sample sizes, randomization tests were performed to evaluate whether mutation rates within ethnic groups differed significantly from those expected based on the ethnic composition of the entire sample.
Results:
The study examined 61 patients (median age 63 years) including: 31 White (51%), 16 Hispanic (26%), 9 American Indian (15%), 4 African American (7%), and 1 Asian (2%). Of the patients tested, 52 underwent tissue-based NGS, 7 had liquid-based NGS, and 2 had both tests performed. The most prevalent genetic alterations were TMPRSS2-ERG fusion (48%), TP53 mutations (41%), PTEN loss/rearrangement (36%), and AR mutations (30%). Comparisons of mutation frequencies across ethnic groups revealed variations in mutation prevalence (Table 1) For most mutations, observed ethnic group frequencies did not differ significantly from expected frequencies based on the total sample (p>0.05), although statistical power was low to detect all but large differences. The exception was BRCA2, where ethnic group frequencies differed significantly from those in the total sample (p=0.025), with no Hispanic patients and equal numbers of White and Native American patients having the mutation.
Conclusions:
This study reveals complex prostate cancer genetic patterns across diverse New Mexican ethnicities. These findings have potential implications for targeted therapies and emphasize the need for larger, more diverse cohorts in research.

Proportion of race and ethnic groups with each mutation.

Mutation
Number Positive
Proportions Within Racial/Ethnic Groups

Hispanic

Native American

Black

White

Asian

TMPRSS2:ERG fusion
29
24.1%
17.2%
0.0%
55.2%
3.4%

TP53
25
24.0%
8.0%
8.0%
60.0%
0.0%

PTEN loss/frameshift
22
27.3%
13.6%
4.5%
54.5%
0.0%

AR Mutations
18
27.8%
5.6%
5.6%
61.1%
0.0%

MYC amplification
11
45.5%
9.1%
0.0%
45.5%
0.0%

PIK3CA
7
28.6%
28.6%
0.0%
42.9%
0.0%

RAD51 R/RAD21 AMP
7
57.1%
14.3%
0.0%
28.6%
0.0%

BRCA2
6
0.0%
33.3%
16.7%
33.3%
16.7%

BRCA1
3
66.7%
0.0%
0.0%
33.3%
0.0%

ATM
3
0.0%
33.3%
0.0%
66.7%
0.0%

All Screened
61
26.2%
14.8%
6.6%
50.8%
1.6%