Danish Bladder Cancer Patients Show Similar Outcomes in Clinical Practice and Clinical Trials

Two studies evaluating all Danish patients with bladder cancer treated with firstline chemotherapy and all-line pembrolizumab, respectively, have found similar outcomes and overall survival rates between patients treated in clinical practice and those from clinical trials. Inspired by these studies, a national database for bladder cancer is being created.

LISE HØJ OMLAND is a MD, PhD, employed as a chief resident physician at the Oncology Department at Rigshospitalet, Copenhagen. Her research interests are centered around bladder cancer, with a special emphasis on real-world evidence.

Real-world evidence is generated from real-world data, which refers to healthcare data derived outside the context of traditional clinical trials. In recent years, the interest in real-world evidence has increased as a source of investigating the effect of a treatment when applied to the heterogeneous patient population in routine clinical practice. This may be particularly important in bladder cancer as patients with bladder cancer are generally considered a frail patient group.

Two nationwide, population-based Danish studies have recently evaluated all Danish patients with bladder cancer treated with first-line chemotherapy and all-line pembrolizumab, respectively.1,2 This article briefly sums up the findings and potential implications.

Real-world evidence comparable to clinical results

The largest of the two studies evaluated 952 patients with metastatic bladder cancer treated with first-line chemotherapy in the period 2010 to 2016. The study showed that despite patients treated in routine clinical practice being older and in a poorer general condition than patients enrolled in clinical trials, treatment responses and overall survival were similar to reportings from clinical trials.

The other study investigated real-world pembrolizumab. It followed 139 patients treated with pembrolizumab during the first year after it was introduced as a standard treatment option in Danish oncology departments. The study demonstrated that pembrolizumab is safe and effective when applied in routine clinical practice, with results similar to those observed in the KEYNOTE-052 and KEYNOTE-045 trials.

Legal challenges implementing real-world studies

A common interest and a close collaboration between the Danish oncology departments managing bladder cancer were essential for conducting the two real-world studies. Despite this common interest, legal constraints made data collection and transfer across the Danish regions difficult. Yet, with substantial extra efforts by the local oncologists involved in the project, this succeeded at last.

Nationwide data collection

Much can be learned from the two real-world studies. Important knowledge of patients with bladder cancer treated in routine clinical practice has been provided, which is valuable for physicians, researchers, regulatory authorities and, in the end, the patients. In addition, we have gained essential knowledge on establishing nationwide data collection. The possibility of gathering nationwide, population-based data is unique in Denmark and should be exploited even more. We hope these two studies can serve as inspiration for similar projects within other cancer types.

Prospective collaborative databases

Inspired by the two real-world studies, an initiative has been taken within the Danish bladder cancer oncology (DaBlaCa) group to establish a national database with the inclusion of prospective data on bladder cancer patients. Data collection will begin when the necessary permits are at hand.

DaBlaCa database already exists, including primarily surgical data. In the future, it may be possible to merge the two databases, thereby increasing the amount and improving the quality of data on this patient group even more.

The collaboration between the Danish oncology departments and other Nordic oncology departments managing bladder cancer is well-established within the Nordic Urothelial Cancer Oncology Group (NUCOG). Hopefully, establishing the prospective Danish database will facilitate future collaborations across the Nordic countries.

References :

1. Omland LH, Lindberg H, Carus A, Als AB, Jensen NV, Taarnhøj GA, et al. Real-world Treatment Patterns and Overall Survival in Locally Advanced and Metastatic Urothelial Tract Cancer Patients Treated with Chemotherapy in Denmark in the Preimmunotherapy Era : A Nationwide, Populationbased Study. European Urology Open Science. 2021 ;24 : 1–8.

2. Omland LH, Stormoen DR, Dohn LH, Carus A, Als AB, Jensen NV, Taarnhøj GY, Tolver A, Pappot H. Real-world study of treatment with pembrolizumab among patients with advanced urothelial tract cancer in Denmark. Original Article. Bladder Cancer. 2021 : 413–425.

CONFLICT OF INTEREST : None.