Explore the deep connection between cancer and genetics

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As the cost of genome and exome sequencing has decreased, its use in characterizing rare diseases and personalizing cancer treatment, for example, is becoming more frequent. However, such analyzes may lead to results unrelated to the condition for which they were requested. What to do with these secondary outcomes (SFs) or incidental outcomes (IFs) is problematic. Should the patient be informed of it and in what circumstances? How should clinical geneticists deal with the unnecessary anxiety they might cause?

At the Annual Conference of the European Society of Human Genetics, Estella Carrasco, MA, Ph.D. A student and genetic counselor at Vall d’Hebron Hospital, Barcelona, ​​Spain, she will describe how she and colleagues set out to look at the prevalence of SF/IFs in cancer susceptibility genes (CSGs) in patients who have undergone exome sequencing due to the paucity of non-cancer diseases, and to identify CSGs with potential on potential clinical work unrelated to the purpose of the fundamental analysis. They then assessed the psychological impact of detecting SF/IFs for patients and their relatives compared to a group tested because of their family history of cancer. They analyzed the exomes of 533 patients screened for non-cancerous indications and followed up with the Psychological Impact Screening for detection of SF/IFs for these patients two to six months after the delivery of the results.

“We found pathogenic SF/IFs variants (that may cause disease) in CSGs in 2% of patients who had exome testing for reasons unrelated to cancer predisposition,” says Carrasco. “This enabled us to run predictive tests on 42 relatives, 18 of whom carry CSGs.”

Psychological impact was higher in those in which the variant was identified as an incidental outcome, but this needs to be weighed against the advantage of early detection and preventive strategies that can be offered in families who did not have a previous diagnosis of cancer, the researchers say. “Although 2% of SF/IFs may not seem very high, they are noticeable,” says Carrasco. “Genetic counseling can help communicate results and help patients and their families adjust to the newly discovered genetic condition.”

The researchers intend to continue researching new ways to present genetic test results to patients; For example, the effect of separating the time at which primary outcomes are detected from secondary outcomes. “We believe that being able to demonstrate the susceptibility of a medical procedure to secondary outcomes reassures patients.”

Of the 29 carriers identified (11 indicator cases and 18 close relatives), 20 were enrolled for further monitoring. Researchers were able to identify three paragangliomas (a type of neuroendocrine tumor), and early breast cancer in a 74-year-old woman with BRCA2 type who completed a population-based breast cancer screening. A relative of the BRCA2 family with metastatic prostate cancer received targeted therapy after his BRCA2 status was detected.

However, special problems appear in the case of children. “The principle of child autonomy may be lost if disclosure is made before an appropriate age, so healthcare professionals should exercise caution when ordering exome sequencing analysis in minors,” says Carrasco. “On the other hand, disclosing these findings could generate an indirect benefit for these children as it may allow their relatives to adhere to early detection and prevention programmes, thus preserving their health. To achieve this, it is important to report only clinically actionable genes.”

“It is important to provide adequate counseling to individuals undergoing exome sequencing, or in the case of children to their parents or guardians, in order to ensure that they understand all potential medical applications of genetic testing. On a professional level, in cases where exome sequencing is requested by clinicians who have With little training in providing information about SF/IFs, genetic counselors and clinical geneticists should form part of the multidisciplinary team providing care.”

Professor Alexandre Raymond, Conference Chair, says that “Unlike radiologists, whose incidental findings suggest a tumor, geneticists’ incidental discoveries are often predictive in nature. While this should not prevent us from acting on an actionable finding, the This requires dedicated and specially trained staff to ensure that all information provided to patients and their families is clear, comprehensible and comprehensible.”


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more information:
Conference: 2022.eshg.org/

Submitted by the European Society of Human Genetics

the quote: Exploring the Deep Link Between Cancer and Genetics (2022, June 10) Retrieved June 10, 2022 from https://medicalxpress.com/news/2022-06-exploring-deep-link-cancer-genetics.html

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