Novel prognostic score for patients with metastatic bladder cancer on immunotherapy using real-world data
Chauhan 1, S. Silva Diaz 2, P. Jara Martin 3, A. Gurung 4, M. Young 1, C. Wells 1, E. Nally 1, B. Szabados 1, F. Jackson-Spence 1, T. Powles 1
(1) Barts Cancer Institute, Centre for Experimental Cancer Medicine, London – United Kingdom, (2) University Hospital A Coruna, Medical Oncology Department, A Coruna – Spain, (3) University Hospital Marqués de Valdecilla, Medical Oncology Department, Santander – Spain, (4) Queen Mary University of London, Barts and The London School of Medicine and Dentistry, London – United Kingdom
Objective:
Some patients with metastatic bladder cancer (mBC) have durable responses to immune checkpoint inhibitors (ICIs); others progress early while suffering from autoimmune toxicity. Currently there is no prognostic score or tumour marker to predict who will benefit from ICIs in bladder cancer. We designed a novel prognostic score to stratify response to ICIs in patients with mBC.
Methods:
We analysed data from patients with mBC receiving ICIs as second- or later-line treatment between 2013–2023. We assessed key patient characteristics and their impact on progression-free survival (PFS) and overall survival (OS) using Kaplan-Meier and Cox-regression methods (retained if p<0.05). Variables independently correlated with OS and PFS on multivariate analysis were selected to create a new score. Radiological response to ICIs was assessed. C-statistic was calculated to assess the model’s fit. SPSS and Stata software were used.
Results:
Between 2013–2023, 149 patients received ICIs for mBC previously treated with at least one line of platinum chemotherapy. Median OS was 9.3 months (IQR2.7–21.4) and median PFS 2.5 months (IQR1.6–6.2). On multivariate analysis, variables independently correlating with improved OS and PFS were absent liver and bone metastases, haemoglobin≥100g/L, alkaline phosphatase≤130unit/L, neutrophil-to-lymphocyte ratio>5, and time from last therapy≥6 months.
Equal weighting was given to each variable to create a new score for stratifying patient outcomes. This 3-tier model that strongly correlated with OS (HR 2.0, 95% CI 1.4–2.4, p<0.001) and PFS(HR 1.7, 95% CI 1.2–2.0, p<0.001). Median OS for patients with 0-1, 2 and 3-5 risk factors was 24.2, 6.7, and 2.4 months, respectively, and complete or partial response was seen in 45.8%, 21.2%, and 6.5%, respectively. This model achieved a C-statistic of 0.70(95% CI 0.65-0.75), which is comparable to those of previous studies.
Conclusions:
We used routinely available metrics from real-world data to develop a new model that stratifies outcomes of patients with mBC receiving post-chemo ICIs. Certain variables suggested by literature, such as ECOG PS, were not found to correlate with survival in our data. The model requires further validation.
Figure
Stratification of overall survival across grouped risk factors to create 3-tier model.