Klin Onkol 2026; 39(1): 56-63. DOI: 10.48095/ccko202656.
Background: Genetic testing for hereditary predisposition to solid tumors using next generation sequencing enables the analysis of a broad spectrum of genes and significantly increases diagnostic yield. However, expanding the scope of analyzed genomic regions also increases the likelihood of identifying so-called secondary findings, defined as pathogenic or likely pathogenic variants in genes unrelated to the primary indication for testing. These findings raise multiple practical, clinical, and ethical challenges. Material and methods: In the Czech Republic, an initiative was launched within the CZECANCA consortium and the Oncogenetics Working Group of the Society of Medical Genetics and Genomics of the Czech Medical Association of J. E. Purkyně with the aim of harmonizing the scope of reporting in cancer predisposition testing within the CZECANCA gene panel. Results: The consensus resulted in a list of genes and variants that should be routinely reported by laboratories during cancer predisposition testing, even in the absence of an explicit request from the indicating medical geneticist. Conclusion: The proposed harmonized approach to reporting secondary findings represents a practical tool for unifying laboratory practice in the Czech Republic. The document reflects the current state of knowledge in oncogenetics and will be regularly updated in response to emerging scientific evidence.