Clinical outcomes of preimplantation genetic testing for hereditary cancer syndromes: A systematic review

A Qualitative Exploration of Oncology Clinician's Needs for PGT-M Discussions in Clinical Practice

Purpose: Oncology clinicians are appropriately positioned to facilitate discussions of assisted reproductive technologies including preimplantation genetic testing for monogenic disease (PGT-M), in the context of cancer treatment or surveillance. Yet, reproductive services, including PGT-M, remain one of the least implemented services in oncology. No studies to date have explored which practice resources the clinicians need to increase knowledge of PGT-M. The objective of this study was to explore the specific needs of oncology clinicians to help maximize the reproductive potential of young adult patients with hereditary cancers. Methods: Participants were recruited through notices circulated on social media platforms and snowball sampling. Participants completed a brief online survey to confirm eligibility. Eligible participants completed a virtual, semi-structured interview. Interviews focused on clinician experiences with PGT-M and initiating referrals to fertility specialists. Thematic analysis was conducted using a constant comparative approach to identify current clinical practices. Results: This study found that PGT-M discussions are not necessarily within the scope of responsibilities for oncology clinicians owing to prioritization of cancer treatment and overall lack of knowledge. Participants need accessible resources and timely support for reproductive planning in the context of cancer treatment. Participants desire a streamlined referral pathway to professionals trained in oncofertility to help address their patient's reproductive needs. Conclusion: Our study identified that educational and referral resources to reproductive specialists are needed to maximize reproductive potential across the cancer continuum. These findings provide a foundation for larger studies that can inform standard-of-care recommendations in the emerging field of oncofertility.

Genetic counseling for pre-implantation genetic testing of monogenic disorders (PGT-M)

Pre-implantation genetic testing (PGT) is a vital tool in preventing chromosomal aneuploidies and other genetic disorders including those that are monogenic in origin. It is performed on embryos created by intracytoplasmic sperm injection (ICSI). Genetic counseling in the area of assisted reproductive technology (ART) has also evolved along with PGT and is considered an essential and integral part of Reproductive Medicine. While PGT has the potential to prevent future progeny from being affected by genetic conditions, genetic counseling helps couples understand and adapt to the medical, psychological, familial and social implications of the genetic contribution to disease. Genetic counseling is particularly helpful for couples with recurrent miscarriages, advanced maternal age, a partner with a chromosome translocation or inversion, those in a consanguineous marriage, and those using donor gametes. Partners with a family history of genetic conditions including hereditary cancer, late onset neurological diseases and with a carrier status for monogenic disorders can benefit from genetic counseling when undergoing PGT for monogenic disorders (PGT-M). Genetic counseling for PGT is useful in cases of Mendelian disorders, autosomal dominant and recessive conditions and sex chromosome linked disorders and for the purposes of utilizing HLA matching technology for creating a savior sibling. It also helps in understanding the importance of PGT in cases of variants of uncertain significance (VUS) and variable penetrance. The possibilities and limitations are discussed in detail during the sessions of genetic counseling.

Application of the PGT-M strategy using single sperm and/or affected embryos as probands for linkage analysis in males with hereditary tumor syndromes without family history

Hereditary tumor syndromes have garnered substantial attention due to their adverse effects on both the physical and psychological health of patients, as well as the elevated risk of transmission to subsequent generations. This has prompted a growing interest in exploring preimplantation genetic testing (PGT) as a treatment option to mitigate and eliminate these impacts. Several studies have demonstrated that de novo variants have become a great cause of many hereditary tumor syndromes, which introduce certain difficulties to PGT. In the absence of adequate genetic linkage information (parents and offspring), haplotype construction seems unrealizable. In the study, researchers used single sperm or affected embryos as proband to perform single-nucleotide polymorphism linkage analysis for cases with de novo variants. For complicated variants, the strategy that sperm combined with embryo detection will increase accuracy while avoiding the limitations and potential failures of using a single detection material. The study recruited 11 couples with male de novo carriers, including 3 tumor types and 4 genes. To date, 4 couples have been clinically confirmed as pregnant and three healthy babies have been born. The results of amniocentesis or umbilical cord blood verification were consistent with the results of PGT-M. The study aims to introduce the application of the PGT-M strategy in hereditary tumor syndromes.

Public Awareness and Acceptability of PGT-M in Cancer Predisposition Syndromes

Cancer Predisposition Syndromes (CPSs), also known as Hereditary Cancer Syndromes (HCSs), represent a group of genetic disorders associated with an increased lifetime risk of developing cancer. In this article, we provide an overview of the reproductive options for patients diagnosed with CPS, focusing on the emerging role of Preimplantation Genetic Testing for Monogenic disorders (PGT-M). Specifically, we conducted a literature review about the awareness and acceptability of its application to CPSs. Based on the available data, the awareness of the applicability of PGT-M for CPSs appears to be limited among both patients and physicians, and a heterogeneous set of factors seems to influence the acceptability of the procedure. Our findings highlight the need for increasing education about the use of PGT-M for CPSs. In this context, guidelines developed by professional or institutional bodies would represent a useful reference tool to assist healthcare professionals in providing proper preconception counseling.

Preimplantation genetic testing for monogenic disorders: clinical experience with BRCA1 and BRCA2 from 2010-2021

PURPOSE

Our aim was to describe the reproductive decisions and outcomes of BRCA-positive patients who used preimplantation genetic testing for monogenic disorders (PGT-M).

METHODS

We performed a retrospective case series of all PGT-M cycles for BRCA variants between 2010-2021 at a large urban academic fertility center. All patients who underwent ≥ 1 cycle of IVF with PGT-M for BRCA1 or BRCA2 were included. The primary outcome was total number of BRCA-negative euploid embryos per patient.

RESULTS

Sixty four patients underwent PGT-M for BRCA variants. Forty-five percent (29/64) were BRCA1-positive females, 27% (17/64) were BRCA2-positive females, 16% (10/64) were BRCA1-positive males, 11% (7/64) were BRCA2-positive males, and one was a BRCA1 and BRCA2-positive male. There were 125 retrieval cycles with PGT-M, and all cycles included PGT for aneuploidy (PGT-A). Eighty-six percent (55/64) of patients obtained at least one BRCA- negative euploid embryo, with median of 1 (range 0-10) BRCA-negative euploid embryo resulted per cycle and median 3 (range 0-10) BRCA-negative euploid embryos accumulated per patient after a median of 2 (range 1-7) oocyte retrievals. Sixty-four percent (41/64) of patients attempted at least one frozen embryo transfer (FET) with a total of 68 FET cycles. Fifty-nine percent (40/68) of embryos transferred resulted in live births. Subgroup analysis revealed different reproductive pathways for BRCA1-positive females, BRCA2-positive females, and BRCA1/2-positive males (p < 0.05).

CONCLUSION

PGT-M is a viable option for BRCA-positive patients to avoid transmission while building their families. Most patients in our cohort achieved pregnancy with BRCA-negative euploid embryos.

Fatalism and metaphor in Confucianism: A qualitative study of barriers to genetic testing among first-degree relatives of hereditary cancer patients from China

OBJECTIVE

Despite the benefits, the rate of genetic testing among first-degree relatives (FDRs; parents, children, and siblings) remains low, and the barriers to undergoing testing among FDRs in China are not clear. We explored the reasons why FDRs refused genetic testing.

METHODS

Semi-structured face-to-face interviews were conducted with 22 patients and 27 FDRs. Participants were recruited at an urban tertiary hospital in Guangzhou, South China. We used qualitative content analysis to analyse the transcripts of audio recordings and identify major themes and subthemes.

RESULTS

Three major themes emerged related to FDRs' low rate of participation in genetic testing. First, there is cognitive distance from genetic testing/cancer and a lack of knowledge of preventive medicine that deepens the 'fatalistic' attitude towards cancer among FDRs, which leads to an enormous gap between their knowledge and understanding of genetic testing. Second, medical consultation is not valued in Confucianism, and the view of cancer as 'bad news' and the risk of cancer as a curse makes cancer a metaphor, which leads to exhausting arguments when persuading FDRs to undergo genetic testing. Third, physical distance from the hospital, loss of privacy, possible discrimination in many social activities and genetic testing as a source of stress and anxiety lead FDRs to fear the disruption of their daily lives.

CONCLUSIONS

There are many barriers to genetic testing among the FDRs of hereditary cancer patients originating from the national social and cultural context. Healthcare professionals should develop interventions rooted in culture and promote cancer risk communication between hereditary cancer patients and FDRs.

Preimplantation genetic testing in patients with genetic susceptibility to cancer

Data on preimplantation genetic testing (PGT-M) in patients with genetic susceptibility to cancer are scarce in the literature, while there is, in our experience, a growing familiarity with assisted reproduction techniques (ART) among pathogenic variant heterozygotes. We performed a retrospective multicenter study of PGT-M outcomes among French patients with genetic susceptibility to cancer. Our objectives were to collect data on this complex issue, and to help cancer geneticists counsel their patients of reproductive age. We also wanted to increase awareness regarding PGT-M among cancer genetics professionals. Patients from three university hospital cancer genetics clinics who had requested PGT-M between 2000 and 2019 were included retrospectively. Data were extracted from medical records. Patients were then contacted directly to collect missing and up-to-date information. Out of 41 eligible patients, 28 agreed explicitly to participate when contacted and were therefore included. They carried PV in VHL (n = 9), APC (n = 8), CDH1 (n = 5), STK11 (n = 2), AXIN2, BRCA1, MEN1, and FH (n = 1). Seven patients were denied PGT-M based on multidisciplinary team meetings or subsequently by the ART hospital teams, two changed their minds, and two were yet to start the process. PGT-M was successful in seven patients (25%), with a mean age at PGT-M request of 27. Most had von Hippel-Lindau. PGT-M failed in the remaining ten, with a mean age at PGT-M request of 32. The main reason for failure was non-implantation of the embryo. Of these, four patients were pursuing PGT-M at the time of last contact. PGT-M outcomes in patients with cancer susceptibility syndromes were satisfactory. These patients should be informed about PGT-M more systematically, which would imply greater awareness among cancer genetics professionals regarding ART. Our series was not representative of cancer susceptibility syndromes in general; the predominance of cases with syndromes characterized by early-onset, highly penetrant disease is explained by the restrictive French guidelines.

A Novel ARMC5 Germline Variant in Primary Macronodular Adrenal Hyperplasia Using Whole-Exome Sequencing

Background: Primary macronodular adrenocortical hyperplasia (PMAH) is a rare form of adrenal Cushing’s syndrome with incomplete penetrance which may be sporadic or autosomal dominant. The inactivation of the ARMC5 gene, a potential tumor suppressor gene, is one of the associated causes of PMAH. This study aimed to identify the variant responsible for Iranian familial PMAH. Methods: The proband, a 44-year-old woman, was directed to whole-exome sequencing (WES) of the blood sample to discover a germline variant. In addition, the identified causative variant was confirmed and segregated in other and available unaffected family members. Results: The novel germline heterozygous missense variant, c.2105C>A in the ARMC5 gene, was found, and the same germline variant as the proband was confirmed in two affected sisters. This variant was detected in the brother of the proband with an asymptomatic condition and this considered because of incomplete penetrance and age-dependent appearance. The function of the ARMC5 protein would be damaged by the identified variant, according to in silico and computer analyses that followed. Conclusion: The new germline ARMC5 variation (c.2105C>A, (p. Ala702Glu)) was interpreted as a likely pathogenic variant based on ACMG and Sherloc standards. PMAH may be diagnosed early using genetic testing that shows inherited autosomal dominant mutations in the ARMC5 gene.