The Danish Bladder Cancer Group 23 Study - A European Study on Cancer in the Upper Urinary Tract

This is a study looking at how patients with a rare type of cancer in the pelvis and ureter of the kidney - called upper urinary tract urothelial carcinoma (UTUC) - is currently treated. The gold standard treatment of UTUC is the complete removal of the kidney, renal pelvis and ureter. The use of kidney-sparing surgery, which preserves the kidney while treating the cancer, was only considered for patients who were too frail to undergo kidney removal, had a solitary functioning kidney, or suffered from severe chronic kidney disease. Since 2018 international guidelines have incorporated kidney sparing surgery for all patients but only offered to patients that have been diagnosed with very low risk tumors to ensure the safety of the patients. The latest update of the UTUC Guidelines from the European Association of Urology has revised the criteria, so that certain features previously classified as high-risk are no longer considered high-risk on their own, provided the tumor otherwise appears benign. Nonetheless, ongoing research is essential to support this evolving approach and to further enhance the guidelines. Kidney sparing surgery comprise of a strict follow up schedule that often demands supplemental surgeries under general anesthesia, which can cause strain on patients. Preservation of the kidney is important since a decrease in kidney function can result in increased risk of cardiovascular disease and death. The main question we want to answer is: Can more patients with superficial non-invasive UTUC safely be treated with kidney-sparing surgery instead of the more aggressive surgery that removes the entire kidney and ureter without increasing the risk of the cancer coming back and while maintaining quality of life? Furthermore, we are interested in learning more about patients who later develop bladder cancer after treatment of UTUC (intravesical recurrences), the affection of kidney function over time and a subgroup of UTUC patients that are diagnosed with