Liquid Biopsies in the Clinical Management of Germ Cell Tumor Patients: State-of-the-Art and Future Directions

Liquid biopsies constitute a minimally invasive means of managing cancer patients, entailing early diagnosis, follow-up and prediction of response to therapy. Their use in the germ cell tumor field is invaluable since diagnostic tissue biopsies (which are invasive) are often not performed, and therefore only a presumptive diagnosis can be made, confirmed upon examination of the surgical specimen. Herein, we provide an overall review of the current liquid biopsy-based biomarkers of this disease, including the classical, routinely used serum tumor markers-the promising microRNAs rapidly approaching the introduction into clinical practice-but also cell-free DNA markers (including DNA methylation) and circulating tumor cells. Finally, and importantly, we also explore novel strategies and challenges for liquid biopsy markers and methodologies, providing a critical view of the future directions for liquid biopsy tests in this field, highlighting gaps and unanswered questions.

Automated summary

Liquid biopsies are a minimally invasive means of managing cancer patients, including early diagnosis and prediction of response to therapy. In the field of germ cell tumors, liquid biopsies are invaluable due to the lack of invasive diagnostic tissue biopsies. Current liquid biopsy-based biomarkers for this disease include serum tumor markers, microRNAs, cell-free DNA markers, and circulating tumor cells. Novel strategies and challenges for liquid biopsy markers and methodologies are being explored, providing insight into the future directions for liquid biopsy tests in this field.