SUO 2018: Role of Adjuvant Therapy - POUT Trial

Phoenix, Arizona  ( The management of patients with upper tract urothelial carcinoma (UTUC) is controversial due to lack of level 1 evidence and rarity of the disease. The standard of care for patients with high-grade disease or those suspected to have invasive disease is nephroureterectomy (NU) with some evidence in support of neoadjuvant or adjuvant platinum-based chemotherapy. During the panel case discussion on management of high-risk UTUC and the role of perioperative chemotherapy in the bladder cancer session at SUO 2018, Dr. Sandy Srinivas, a medical oncologist at Stanford University summarized the results from POUT trial.

She started her talk by outlining the POUT trial, which was a multicenter collaboration from the UK, designed to enroll 360 patients but stopped enrolling patients due to the decison of the safety data monitoring committee observing significant improvement in DFS. It is the first trial evaluating the use of adjuvant chemotherapy within 90 days following a NU. Between May 2012 and September 2017, 260 patients were enrolled (129 surveillance; 131 chemotherapy) at 57 UK centers, with locally advanced or node-positive UTUC (pT2-T4 N0-3 M0). The patients were then randomized (1:1) to 4 cycles of gemcitabine-cisplatin (GFR ≥ 50 ml/min)/gemcitabine-carboplatin (GFR 30-49 ml/min) or surveillance 90 days following an NU. Patients with a GFR < 30, and those with an incompletely resected macroscopic disease where excluded from the trial. Patients were followed closely with cross-sectional imaging and cystoscopy every 6 months for the first two years and transitioned to annual follow-up for a total of 5 years. The primary end-point for the trial was disease-free survival (DFS), with recurrence-free survival (RFS), overall survival (OS), toxicity and quality of life (QoL) as secondary end-points.

Baseline characteristics were comparable between the groups. The majority of patients enrolled had pT3 disease (28% pT2, 65% pT3) and were node negative following node dissection (91%). A significant difference in DFS (HR 0.49 [CI 0.31-0.76], p=0.001) was observed at a median follow-up of 17.6 months. Following adjustment for nodal involvement, microscopic margin status and planned chemotherapy type, the difference was more pronounced with an HR 0.47 [CI 0.30-0.74), p=0.001). On secondary end-points, adjuvant chemotherapy was also associated with an improvement in recurrence-free survival (HR 0.49 (0.30-0.78), p=0.02). A separation in the OS curves was seen, but the difference remains non-significant likely related to the early analysis. Patients randomized to chemotherapy had lower global health status during chemotherapy, which was secondary to nausea, vomiting, and fatigue but no difference was noted at 12 and 24 months when compared to patients who were on surveillance.

Dr. Srinivas concluded her talk by summarizing that the POUT trial provides convincing level 1 evidence on the added value of adjuvant chemotherapy in patients with locally advanced or node-positive UTUC. The follow-up for overall survival is ongoing, and it will be interesting to see those results.

Presented by: Sandy Srinivas, MD, Stanford University, Stanford, California

Written by: Abhishek Srivastava, MD, Society of Urologic Oncology Fellow, Fox Chase Cancer Center, Fox Chase Cancer Center, Philadelphia, PA, @shekabhishek, at the 19th Annual Meeting of the Society of Urologic Oncology (SUO), November 28-30, 2018 – Phoenix, Arizona