Honing the Hunt: A Comprehensive Review of Cell-free Tumor DNA to Predict Neoadjuvant Therapy Efficacy in Bladder Cancer

Objective To provide an updated view on the role of cell-free DNA as a predictor of pathological response to neoadjuvant therapy in patients with muscle-invasive bladder cancer. Methods A systematic review was conducted from September 2023 until October 2023. Selected studies from the MEDLINE and clinical trial databases were critically analyzed regarding the clinical efficacy of cell-free DNA as a predictive instrument after neoadjuvant therapy in bladder cancer. The methodological quality assessment was based on the QUADAS-2 tool. Results In this systematic review, we analyzed five studies encompassing a cumulative patient cohort of 780 individuals diagnosed with Muscle-Invasive Bladder Cancer, with a median follow-up ranging from 6 to 23 months. Among these studies, four primarily focused on detecting and analyzing circulating tumor DNA in plasma, while one study uniquely utilized cell-free tumor DNA in urine samples.The diagnostic accuracy of cell-free DNA in plasma ranges from 79% to 100%, indicating a variable yet significant predictive capability. In contrast, the study utilizing urinary cell-free DNA demonstrated an accuracy of 81% in predicting treatment response post-neoadjuvant chemotherapy. Conclusion Cell-free DNA is emerging as a valuable biomarker for predicting response to neoadjuvant chemotherapy in patients with muscle-invasive bladder tumors.