Researchers who treated a group of post-surgery bladder cancer patients with the immunotherapy drug atezolizumab have found that patients whose blood contained circulating tumor DNA (ctDNA), responded very well to the treatment. The research was part of a larger Phase III trial which looked at whether giving atezolizumab for up to one year to patients following bladder removal surgery improved the patients' survival prospects, compared to a group that received no further treatment after surgery but placed in an observation group. Part of that trial involved patients' levels of ctDNA being measured after surgery, and during further treatment or observation....