| Theme | Lynch Syndrome and Hereditary Polyposis Syndromes | |
|---|---|---|
| Title | Genetic Counseling for Cancer | |
| Publish Date | 2019/06 | |
| Author | Masami Arai | Diagnostics and Therapeutics of Intractable Diseases, Juntendo University, Graduate School of Medicine |
| [ Summary ] | Providing appropriate information and psychosocial support is essential to carry out genetic counseling for hereditary cancer syndromes. There are effective therapies or preventive procedures (e. g. risk reducing salpingo‒oophorectomy in BRCA1/2 mutation carriers) available for many hereditary cancer syndromes, and genetic information of patients with hereditary cancer syndrome can to be effectively utilized in clinical practice, as early detection and treatment can lead to increased survival. Lynch syndrome, which is a representative hereditary cancer syndrome, is at first screened based on clinical information and microsatellite instability (MSI) testing, and finally diagnosed by genetic testing. This process is performed in classical genetic counseling. Recently, another aspect of genetic testing has emerged, leading to a new type of genetic counseling. MSI testing is currently also being performed as a companion diagnostic (CDx) for anti PD‒1 drugs treatment in clinical divisions in addition to screening for Lynch syndrome and cancer panel testing for choice of molecular target‒based drugs will be used shortly in Japan. As a result, Lynch syndrome could be secondarily diagnosed through CDx or cancer panel testing. In such cases, clinicians will be required to inform patients about the possible secondary diagnosis of hereditary cancer syndromes beforehand in order to prepare them for such an eventuality. New type of genetic counseling for cancer should, therefore, not only focus on the proband's treatment, but also on sharing the proband's genetic information with her or his relatives to improve their healthcare, although many probands suffer from metastatic or recurrent cancers. |
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