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... Show moreBackground: 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 hered-itary cancer), follow-up by prostate-specific antigen was considered appropriate. For patients with low-risk localised PCa and a family history of PCa, active surveil-lance was considered appropriate, except in case of the patient being a BRCA2 germ -line 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 fol-lows: (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.(c) 2022 The Author(s). Published by Elsevier B.V. on behalf of European Association of Urology. This is an open access article under the CC BY license (http://creativecommons. org/licenses/by/4.0/). Show less
Speight, B.; Colvin, E.; Epurescu, E.D.; Drummond, J.; Verhoef, S.; Pereira, M.; ... ; Tischkowitz, M. 2022
Germline pathogenic variants in BRCA1 and BRCA2 cause hereditary breast and ovarian cancer. The vast majority of these variants are inherited from a parent. De novo constitutional pathogenic... Show moreGermline pathogenic variants in BRCA1 and BRCA2 cause hereditary breast and ovarian cancer. The vast majority of these variants are inherited from a parent. De novo constitutional pathogenic variants are rare. Even fewer cases of constitutional mosaicism have been reported and these have mostly been described in women with breast cancer. Here we report low-level constitutional mosaicism identified by Next Generation Sequencing in two women with ovarian cancer. A BRCA1 c.5074G > A p.(Asp1692Asn) variant detected in the first female at 42 years, classed as likely pathogenic, was found in similar to 52% of reads in DNA extracted from tumour, similar to 10% of reads in DNA extracted from peripheral blood leukocytes and similar to 10% of reads in DNA extracted from buccal mucosa. The second BRCA c.2755_2758dupCCTG p.(Val920AlafsTer6) variant was detected in a female aged 53 years, classed as pathogenic, and was found in similar to 59% of reads in DNA extracted from tumour, similar to 14% of reads in DNA extracted from peripheral blood leukocytes and similarly in similar to 14% of reads in both DNA extracted from buccal mucosa and urine sample. Sanger sequencing confirmed the presence of these variants at a corresponding low level consistent with mosaicism that may not have been detected by this method alone. This report demonstrates the clinical benefit for two women of BRCA1/BRCA2 germline NGS testing at a depth that can detect low-level mosaicism. As well as informing appropriate treatments, tumour sequencing results may facilitate the detection and interpretation of low-level mosaic variants in the germline. Both results have implications for other cancer risks and for relatives when providing a family cancer risk assessment and reproductive risk. The implications for laboratory practice, clinical genetics management and genetic counselling for constitutional mosaicism of BRCA1/BRCA2 are discussed. Show less
Multigene panel testing is mainly used to improve identification of genetic causes in families with characteristics fitting multiple possible cancer syndromes. This technique may yield uncertainty,... Show moreMultigene panel testing is mainly used to improve identification of genetic causes in families with characteristics fitting multiple possible cancer syndromes. This technique may yield uncertainty, for example when variants of unknown significance are identified. This study explores counsellors' and counselees' experiences with uncertainty, and how they discuss uncertainties and decide about multigene panel testing. Six focus groups were conducted including 38 counsellors. Twelve counselees who had received genetic counselling about a multigene panel test were interviewed. The focus group sessions and interviews were audio-recorded and transcribed verbatim. Transcripts were analysed inductively by two independent coders and data were examined to obtain a comprehensive list of themes. Counsellors identified several uncertainties, e.g. finding a variant of unknown significance, or detecting an unsolicited finding. Most difficulty was experienced in deciding what uncertain information to communicate to counselees and how to do so. The extent and manner of providing uncertain information differed between centres and between counsellors. Counsellors attached more value to counselees' preferences in decision making compared to less extended tests. Counselees experienced difficulty in recalling which uncertainties had been discussed during genetic counselling. They primarily reported to have experienced uncertainty about their own and their relatives' risk of developing cancer. Counselees felt they had had a say in the decision. This study showed that counsellors need more guidance on whether and how to convey uncertainty. Undesirable practice variation in the communication of uncertainty may be prevented by determining what information should minimally be discussed to enable informed decision making. Show less
The cumulative lifetime risk of developing breast cancer for a Dutch woman is about 12%. In some families breast cancer seems to occur even more frequently or women fall ill at a relatively young... Show moreThe cumulative lifetime risk of developing breast cancer for a Dutch woman is about 12%. In some families breast cancer seems to occur even more frequently or women fall ill at a relatively young age. Such families may have a genetic susceptibility towards breast cancer. To learn more about the likelihood of this susceptibility actually being present, members of such families may request genetic counselling and DNA-testing. The main purpose of this thesis is to provide more insight into some effects of genetic counselling and DNA testing for breast cancer. We address effects on: (a) risk perception; (b) psychological distress; and (c) intentions for risk-management behaviour. Regarding the effects of DNA testing, special attention is paid to women who receive a so-called uninformative DNA-test result. The data of this thesis do not provide support for one of the two hypotheses which has been postulated about the impact of an uninformative result. They suggest that, as a group, women seem to be reassured upon learning their uninformative result, but to a lesser extent than women who received a true negative result. Only a small minority of women with an uninformative result incorrectly concluded that the chance of a mutation being present was non-existent. Show less
