What is the fine-grained topic of the following text: To evaluate tumor-associated genomic and genetic variations in plasma cell-free DNA (cfDNA) and their associations with treatment response and overall survival, we applied whole genome and targeted sequencing to examine the plasma cfDNAs derived from 20 patients with advanced prostate cancer. Only return the topic.
Evaluating tumor-associated genomic variations in plasma cell-free DNA in advanced prostate cancer patients