The Cambridge Prognostic Groups for improved prediction of disease mortality at diagnosis in primary non-metastatic prostate cancer
Over 80% of the nearly 1 million men diagnosed with prostate cancer annually worldwide present with localised or locally advanced non-metastatic disease. Risk stratification is the cornerstone for clinical decision making and treatment selection for these men. The most widely applied stratification systems use presenting prostate-specific antigen (PSA) concentration, biopsy Gleason grade, and clinical stage to classify patients as low, intermediate, or high risk. There is, however, significant heterogeneity in outcomes within these standard groupings and many men get under treated and overtreated because of it.
Cambridge led research has now developed a new more accurate model (Cambridge Prognostic Groups) to stratify men newly diagnosed with prostate cancer by their prognosis. This model used the standard clinic-pathological data collected at diagnosis and therefore has no added costs.
It is the first model built in a UK population and we showed that the accuracy of the new model is over 80% and this was consistent in 3 international cohorts including over 86,000 men. In addition, it contextualises the disease related mortality within other competing risks of death. These data have been published in PLoS Medicine (Gnanapragasam et al 2016) and BMC Medicine (Gnanapragasam et al 2018)
The CPG model identifies a sub-cohort of men who do not benefit from immediate treatment thus saving many thousands of operations and radiotherapy sessions. Equally it identified men who are doing particularly badly despite treatment and urgently need new interventions. We estimate that the model could prevent up to 8000 men annually from having unnecessary radical therapy in the UK alone. We are now using it to reframe how we develop early detection tests and how we refine the use of imaging and staging tests in our ongoing research programme .
The CPG model has now been built into a webtool with the aim of allowing access to any clinician for use in clinics and treatment planning in the UK and Internationally. The model can be accessed by clicking the image below and a 1 off registration will be needed. It is also already been built into Cambridge University Hospitals EPIC tool for clinical use.
Click on the image below to access the online calculator
Important Notice : The Cambridge Prognostic Group criteria is a prognostic tool for patients diagnosed with non-metastatic prostate cancer who have not yet begun treatment and in whom metastatic disease has not yet been identified. The key factors needed to generate a result are PSA at diagnosis (ng/ul), highest Gleason Grade Group (2015 ISUP criteria), stage (either by clinical examination /radiological). This on line calculator model is based on data from men diagnosed and managed in the UK and Sweden . Please refer to the referenced papers in the model to understand the populations it was derived from and tested. The model assesses the potential benefits of immediate radical treatment (either by radical prostatectomy or radical radiotherapy) versus the option of initial conservative management/active surveillance in terms of the likelihood of dying of prostate cancer over a 10 year period. The model does not preclude the potential need for deferred radical treatment after initial conservative management if the disease characteristics change. It also allows comparison against the risk of dying of a non-prostate cancer related cause stratified by age groups. The Cambridge Prognostic Group is designed as a guide to add information to standard counseling and personal discussion with a health care professional and cannot replace it. All results must be understood in the context of each patient’s specific condition. In particular, the model does not adjust for factors such as family history, race, tumour volume/biopsy core involvement or predisposing genetic factor