Pathogenic Germline DNA Repair Gene and HOXB13 Mutations in Men With Metastatic Prostate Cancer

Germline pathogenic variants in prostate cancer

While most prostate cancer is sporadic, evidence suggests that a significant minority of cases have a hereditary component, and germline variants may play a role in this heritability. In this study, we investigated germline pathogenic variants in prostate cancer patients. All genetic variants were classified using the American College of Medical Genetics and Genomics/Association for Molecular Pathology 2015 guidelines. By retrospectively reviewing patient charts and genetic testing results, we collected clinicopathologic, demographic, and genetic data. Among the 160 prostate cancer patients who met NCCN genetic testing guidelines and underwent germline testing, 41 % had metastatic cancer, while 59 % had localized cancer, mostly high-risk. Nineteen (19) out of the 160 patients (12 %) had a pathogenic or likely pathogenic variant in the following genes: MUTYH (3.1 %), ATM (1.9 %), BRCA2 (1.3 %), CHEK2 (1.3 %), PALB2 (1.3 %), HOXB13 (1.3 %), and 5 other genes (BRIP1, LZTR1, TP53, NTHL1, and NBN), each at a frequency of 0.6 %. There was no significant difference in clinicopathologic data (such as age, serum prostate-specific antigen, Gleason score, and others) between those with a pathogenic or likely pathogenic variant and those without. There was also a lack of significant difference in the number of variants of uncertain significance observed between different racial and ethnic groups. Individuals with a family history of cancer were significantly more likely to have a pathogenic or likely pathogenic variant than those without one (p = 0.002). Overall, our results show the necessity for future research with a larger sample size to better explain the relationship between clinicopathologic data and genetic variants.

Study of HOXB13 Gene Variants in Prostate Cancer Patients

BACKGROUND

Prostate cancer (PC) is a prevalent malignancy with a significant hereditary component. The HOXB13 gene, encoding a transcription factor involved in prostate development, has been implicated in PC risk.

OBJECTIVE

The objective of this study was to assess the existence of HOXB13 mutations in PC patients.

METHOD

The retrospective study included 33 PC patients and 23 controls. Demographic data, family history, and smoking habits were recorded. Prostate-specific antigen (PSA) levels were measured. We investigated the second exon of HOXB13 after extracting genomic DNA from blood samples for mutations using polymerase chain reaction and Sanger sequencing.

RESULT

PC patients had a higher mean age (64.7 years), more frequent positive family history (63.64%, N = 21), and higher smoking prevalence (60.61%, N = 20) compared to controls. PSA levels were significantly elevated in patients (76.58 ng/ml) versus controls (7.22 ng/ml). HOXB13 mutations, including thymine (3.03%, N = 1), guanine (27.27%, N = 9), and adenine (33.33%, N = 11) mutations, were observed in patients, while no mutations were found in controls.

CONCLUSION

PC patients had higher mean age, more positive family histories, higher smoking rates, and elevated PSA levels. HOXB13 mutations were significantly higher in patients compared to controls. These findings emphasize the roles of HOXB13, age, family history, smoking, and PSA in PC risk stratification.

Role of homeobox genes in cancer: immune system interactions, long non-coding RNAs, and tumor progression

The intricate interplay between Homeobox genes, long non-coding RNAs (lncRNAs), and the development of malignancies represents a rapidly expanding area of research. Specific discernible lncRNAs have been discovered to adeptly regulate HOX gene expression in the context of cancer, providing fresh insights into the molecular mechanisms that govern cancer development and progression. An in-depth comprehension of these intricate associations may pave the way for innovative therapeutic strategies in cancer treatment. The HOX gene family is garnering increasing attention due to its involvement in immune system regulation, interaction with long non-coding RNAs, and tumor progression. Although initially recognized for its crucial role in embryonic development, this comprehensive exploration of the world of HOX genes contributes to our understanding of their diverse functions, potentially leading to immunology, developmental biology, and cancer research discoveries. Thus, the primary objective of this review is to delve into these aspects of HOX gene biology in greater detail, shedding light on their complex functions and potential therapeutic applications.

Evaluation of homeobox protein B13 (HOXB13) gene G84E mutation in patients with prostate cancer

OBJECTIVES

To comprehensively investigate the potential association between prostate cancer (PCa) and the G84E mutation within the Homeobox Protein B13 (HOXB13) gene among individuals of Turkish descent, our study aims to undertake a prospective examination.

METHODS

We evaluated 300 patients (150 diagnosed with prostate cancer, 150 controls) who presented in our clinic. Data collected were prospectively examined. DNA isolation was performed using an isolation kit. The HOXB13-G84E mutation (rs138213197) was analyzed in the obtained samples. Data encoding and statistical analysis were performed.

RESULTS

The pathological allele for the G84E mutation was T. According to the findings, no mutations were detected in the control group, while the G84E mutation was detected in 17 patients in the patient group, all of whom had the TC genotype. The analysis showed that having the CC genotype reduced the risk of prostate cancer by 0.47 times (OR=0.47, CI=0.415-0.532). Our results did not support a trend toward family history or earlier-onset disease in comparisons between carriers and non-carriers of HOXB13 G84E mutation. Individuals with a positive family history exhibited a higher frequency of the G84E mutation.

CONCLUSIONS

We concluded that HOXB13 gene mutation is indeed linked to PCa in Turkish men. However, we did not find a relationship between the HOXB13 gene G84E mutation carrier status and either early-onset PCa or familial PCa in Turkish men.

Men with metastatic prostate cancer carrying a pathogenic germline variant in breast cancer genes: disclosure of genetic test results to relatives

Some patients with metastatic prostate cancer carry a pathogenic germline variant (PV) in a gene, that is mainly associated with an increased risk of breast cancer in women. If they test positive for such a PV, prostate cancer patients are encouraged to disclose the genetic test result to relatives who are at risk in case the carrier status changes the relatives' medical care. Our study aimed to investigate how men who learned they carry a PV in BRCA1, BRCA2, PALB2, CHEK2 or ATM disclosed their carrier status to at-risk relatives and to assess the possible psychological burden for the carrier and their perception of the burden for relatives. In total, 23 men with metastatic prostate cancer carrying a PV completed the IRI questionnaire about family communication; 14 also participated in a semi-structured interview. Patients felt highly confident in discussing the genetic test result with relatives. The diagnosis of prostate cancer was experienced as a burden, whereas being informed about genetic testing results did in most cases not add to this burden. Two patients encountered negative experiences with family communication, as they considered the genetic test result to be more urgent than their relatives. This mixed-methods study shows that metastatic prostate cancer patients with a PV in genes mainly associated with increased risk of breast cancer feel well-equipped to communicate about this predisposition in their families. Carriers felt motivated to disclose their genetic test result to relatives. Most of them indicated that the disclosure was not experienced as a psychological burden.

Germline DNA Repair Genes Pathogenic Variants Among Mexican Patients With Prostate Cancer

BACKGROUND

Early identification of germline mutation carriers may be relevant for the optimal management of prostate cancer and to inform cancer risk in relatives. However, population minorities have limited access to genetic testing. The aim of this study was to describe the frequency of DNA repair gene pathogenic variants (PVs) among Mexican men with prostate cancer referred for Genomic Cancer Risk Assessment and testing.

METHODS

Patients diagnosed with prostate cancer who meet criteria for genetic testing and enrolled in the Clinical Cancer Genomics Community Research Network at the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán in Mexico City were included. Descriptive statistics were performed using frequency and proportions for categorical variables and median and range for quantitative variables. X2 and t test were used for group comparisons.

RESULTS

A total of 199 men were enrolled, median age at diagnosis was 66 (range 44-88) years; 45% were de novo metastatic and 44% were high- very high and 10% were intermediate risk group. Four (2%) had a pathogenic germline variant; one each of the following genes: ATM, CHEK2, BRIP1, and MUTYH (all monoallelic). Younger men at diagnosis were more likely to carry a PV than older age at diagnosis (56.7 vs. 66.4 years, P = .01).

CONCLUSION

Our results showed a low prevalence of known prostate cancer associated PVs and no BRCA PVs in Mexican men with prostate cancer. This suggests that the genetic and/or epidemiologic risk factors for prostate cancer are not well characterized in this specific population.

Genetic Aspects and Molecular Testing in Prostate Cancer: A Report from a Dutch Multidisciplinary Consensus Meeting

Background

Germline and tumour genetic testing in prostate cancer (PCa) is becoming more broadly accepted, but testing indications and clinical consequences for carriers in each disease stage are not yet well defined.

Objective

To determine the consensus of a Dutch multidisciplinary expert panel on the indication and application of germline and tumour genetic testing in PCa.

Design setting and participants

The panel consisted of 39 specialists involved in PCa management. We used a modified Delphi method consisting of two voting rounds and a virtual consensus meeting.

Outcome measurements and statistical analysis

Consensus was reached if ≥75% of the panellists chose the same option. Appropriateness was assessed by the RAND/UCLA appropriateness method.

Results and limitations

Of the multiple-choice questions, 44% reached consensus. For men without PCa having a relevant family history (familial PCa/BRCA-related hereditary cancer), follow-up by prostate-specific antigen was considered appropriate. For patients with low-risk localised PCa and a family history of PCa, active surveillance was considered appropriate, except in case of the patient being a BRCA2 germline pathogenic variant carrier. Germline and tumour genetic testing should not be done for nonmetastatic hormone-sensitive PCa in the absence of a relevant family history of cancer. Tumour genetic testing was deemed most appropriate for the identification of actionable variants, with uncertainty for germline testing. For tumour genetic testing in metastatic castration-resistant PCa, consensus was not reached for the timing and panel composition. The principal limitations are as follows: (1) a number of topics discussed lack scientific evidence, and therefore the recommendations are partly opinion based, and (2) there was a small number of experts per discipline.

Conclusions

The outcomes of this Dutch consensus meeting may provide further guidance on genetic counselling and molecular testing related to PCa.

Patient summary

A group of Dutch specialists discussed the use of germline and tumour genetic testing in prostate cancer (PCa) patients, indication of these tests (which patients and when), and impact of these tests on the management and treatment of PCa.

Mainstream germline genetic testing in men with metastatic prostate cancer: design and protocol for a multicenter observational study

BACKGROUND

In international guidelines, germline genetic testing is recommended for patients with metastatic prostate cancer. Before undergoing germline genetic testing, these patients should receive pre-test counseling. In the standard genetic care pathway, pre-test counseling is provided by a healthcare professional of a genetics department. Because the number of patients with metastatic prostate cancer is large, the capacity in the genetics departments might be insufficient. Therefore, we aim to implement so-called mainstream genetic testing in the Netherlands for patients with metastatic prostate cancer. In a mainstream genetic testing pathway, non-genetic healthcare professionals discuss and order germline genetic testing. In our DISCOVER study, we will assess the experiences among patients and non-genetic healthcare professionals with this new pathway.

METHODS

A multicenter prospective observational cohort study will be conducted in 15 hospitals, in different regions of the Netherlands. We developed an online training module on genetics in prostate cancer and the counseling of patients. After completion of this module, non-genetic healthcare professionals will provide pre-test counseling and order germline genetic testing in metastatic prostate cancer patients. Both non-genetic healthcare professionals and patients receive three questionnaires. We will determine the experience with mainstream genetic testing, based on satisfaction and acceptability. Patients with a pathogenic germline variant will also be interviewed. We will determine the efficacy of the mainstreaming pathway, based on time investment for non-genetic healthcare professionals and the prevalence of pathogenic germline variants.

DISCUSSION

This study is intended to be one of the largest studies on mainstream genetic testing in prostate cancer. The results of this study can improve the mainstream genetic testing pathway in patients with prostate cancer.

TRIAL REGISTRATION

The study is registered in the WHO's International Clinical Trials Registry Platform (ICTRP) under number NL9617.

Germline Variants in DNA Damage Repair Genes and HOXB13 Among Black Patients With Early-Onset Prostate Cancer

PURPOSE

Genetic studies of prostate cancer susceptibility have predominantly focused on non-Hispanic White men, despite the observation that Black men are more likely to develop prostate cancer and die from the disease. Therefore, we sought to identify genetic variants in Black patients diagnosed with early-onset prostate cancer.

METHODS

Whole-exome sequencing of germline DNA from a population-based cohort of Black men diagnosed with prostate cancer at age 62 years or younger was performed. Analysis was focused on a panel of DNA damage repair (DDR) genes and HOXB13. All discovered variants were ranked according to their pathogenic potential based upon REVEL score, evidence from existing literature, and prevalence in the cohort. Logistic regression was used to investigate associations between mutation status and relevant clinical characteristics.

RESULTS

Among 743 Black prostate cancer patients, we identified 26 unique pathogenic (P) or likely pathogenic (LP) variants in 14 genes (including HOXB13, BRCA1/2, BRIP1, ATM, CHEK2, and PALB2) among 30 men, or approximately 4.0% of the patient population. We also identified 33 unique variants of unknown significance in 16 genes among 39 men. Because of the rarity of these variants in the population, most associations between clinical characteristics did not achieve statistical significance. However, our results suggest that carriers for P or LP (P/LP) variants were more likely to have a first-degree relative diagnosed with DDR gene-associated cancer, have a higher prostate-specific antigen at time of diagnosis, and be diagnosed with metastatic disease.

CONCLUSION

Variants in DDR genes and HOXB13 may be important cancer risk factors for Black men diagnosed with early-onset prostate cancer, and are more frequently observed in men with a family history of cancer.

Clinical Germline Testing Results of Men With Prostate Cancer: Patient-Level Factors and Implications of NCCN Guideline Expansion

Germline likely pathogenic or pathogenic variants (PVs) have been identified in up to 17% of men with prostate cancer (PC) and may drive disease severity or be targetable by novel therapies. National Comprehensive Cancer Network (NCCN) guidelines encouraging germline testing in metastatic PC were recently expanded to include all men with high-risk, very high-risk, or regional PC. Our aim was to assess the impact of expanded NCCN guidelines on the detection rate of germline PVs and to determine patient-level factors associated with a PV germline testing result.

PATIENTS AND METHODS

Men with PC underwent multigene germline genetic testing for PVs from June 2016 to December 2018, and trends were compared. The association of patient-level factors with a PV germline testing result, where ≥ 1 PV was identified, was assessed using analysis of variance and univariate logistic regression. Sensitivity analyses were limited to clinically actionable variants and those associated with disease severity or progression (BRCA1/2 and ATM).

RESULTS

Of 408 men undergoing germline testing, 42 (10.3%) men had PVs and 366 (89.7%) men did not have PVs identified. The proportion of men identified with a germline PV remained stable following testing criteria expansion (9.4% v 10.6%, P = .73). No patient-level factors were significantly associated with increased odds of a PV germline testing result, including age at diagnosis, race, pretreatment prostate-specific antigen, Gleason grade group, NCCN risk group, and family history of cancer (breast and/or ovarian, prostate, or any cancer).

CONCLUSION

This study demonstrated a stable PV detection rate in men with PC using expanded criteria aligned to the updated NCCN testing guidelines. However, we did not find strong evidence to suggest that patient-level factors are associated with PV germline testing results. These findings support the recent expansion of NCCN germline testing guidelines in PC.