Surveillance of the Genetic Signature in Circulating Tumor DNA for Guiding Adjuvant Chemotherapy in Urothelial Carcinoma

Urothelial carcinomas are one of the most commonly diagnosed cancers worldwide. Postoperative patients carry a poor prognosis with an estimated five-year disease-specific survival rate of 50%. To improve overall survival and reduce the recurrent risk, chemotherapy is recommended as a standard of care. However, currently in Hong Kong, neoadjuvant (preoperational) chemotherapy and adjuvant (postoperative) chemotherapy are not commonly or regularly provided due to the concern of the potential harm from both physicians and patients. Recently, genetic signature from circulating tumor DNA (ctDNA) is emerging as a pivotal biomarker for detecting caner in early stage and molecular residual disease (MRD). With strengths of non-invasive and superior sensitivity, ctDNA is hopefully to serve as a cancer-agnostic surrogate analyte for risk stratification of tumor recurrence, thereby guiding individually tailored treatment. Therefore, this study is proposed to exploratively assess the benefit of ctDNA-guided approach for postoperative adjuvant therapy.