PhD defence F.C. (Florus) de Jong

Below is a brief summary of the dissertation: 

The overall aim of this dissertation is to predict recurring and progressive disease in patients with bladder cancer based on clinical, pathological and molecular features of the tumor. Accurate prediction of disease outcome is useful for clinicians to provide patients personalized management of bladder cancer.

The first part of this dissertation involves investigation of patients with non-muscle invasive bladder cancer. After a transurethral resection of the bladder tumor, patients receive six consecutive bladder instillations via a catheter, once a week, with BCG immunotherapy. BCG causes an immune response that eradicates remaining cancer cells after bladder surgery. If tumors do no recur, BCG instillations are repeated every 3-6 months, up to 3 years. Unfortunately, BCG is only effective in 50% of patients. If patients do no respond to BCG, the bladder is removed and a urostomy constructed. In our study, we developed a molecular test and applied a pathological biomarker that predicts response to BCG treatment, so that another therapy can be offered beforehand. We also discovered that patients who would normally receive an immediate bladder removal, now can be safely treated with BCG.

In the second part of this dissertation we investigated the use of DNA test in urine, which detects tumor recurrences in non-muscle invasive bladder cancer patients who received BCG, or muscle-invasive bladder cancer patients who received curative (chemo)radiation treatment. We prospectively validated that the urine test can be used to detect bladder cancer during surveillance, and we found that the test predicts future tumor recurrences, long before these can be seen by the visible eye during cystoscopy. We suggest that surveillance protocols can be altered is the test is negative, so that patients with negative test results do not as many need invasive and uncomfortable endoscopic procedures.