Risk stratification for prostate cancer management: value of the Cambridge Prognostic Group classification for assessing treatment allocation

Abstract

Background: The five-tiered Cambridge Prognostic Group (CPG) classification is a better predictor of prostate cancer-specific mortality than the traditional three-tiered classification (low, intermediate, and high risk). We investigated radical treatment rates according to CPG in men diagnosed with non-metastatic prostate cancer in England between 2014 and 2017. Methods: Patients diagnosed with non-metastatic prostate cancer were identified from the National Prostate Cancer Audit database. Men were risk stratified according to the CPG classification. Risk ratios (RR) were estimated for undergoing radical treatment according to CPG and for receiving radiotherapy for those treated radically. Funnel plots were used to display variation in radical treatment rates across hospitals. Results: A total of 61,999 men were included with 10,963 (17.7%) in CPG1 (lowest risk group), 13,588 (21.9%) in CPG2, 9452 (15.2%) in CPG3, 12,831 (20.7%) in CPG4, and 15,165 (24.5%) in CPG5 (highest risk group). The proportion of men receiving radical treatment increased from 11.3% in CPG1 to 78.8% in CGP4, and 73.3% in CPG5. Men in CPG3 were more likely to receive radical treatment than men in CPG2 (66.3% versus 48.4%; adjusted RR 1.44; 95% CI 1.36-1.53; P < 0.001). Radically treated men in CPG3 were also more likely to receive radiotherapy than men in CPG2 (59.2% versus 43.9%; adjusted RR, 1.18; 95% CI 1.10-1.26). Although radical treatment rates were similar in CPG4 and CPG5 (78.8% versus 73.3%; adjusted RR 1.01; 95% CI 0.98-1.04), more men in CPG5 had radiotherapy than men in CPG4 (79.9% versus 59.1%, adjusted RR 1.26; 95% CI 1.12-1.40).

Long‐term survival after low‐dose‐rate brachytherapy for prostate cancer: the Royal Surrey experience

“…The definition of risk categories continues to evolve and there is an emerging argument for using a more granular classifier, based primarily on the five‐tier International Society of Urological Pathology grading system, to reduce under‐/overtreatment [16]. There is no evidence, however, from the present study or others [13] to indicate that Gleason score is a significant predictor of long‐term mortality.…”

“…Of these, 1932 (85%) had annotated 48-month (AE6 months) PSA values in BrachyBase. For the remaining 353 patients (15%) the 48-month value was derived from their PSA history by linear regression (the median [range] post implant PSA measurement count was 9 [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] and all cases had at least one value either side of the 48-month time point).…”

Comparison of the treatment of men with prostate cancer between the US and England: an international population-based study

“…The majority of CPG2 cases ('favourable' intermediate-risk) are being treated radically in both the US (69%) and England (53%). This brings into focus the lack of consensus within national guidelines regarding the management of these cases (25)(26)(27). The adoption of active surveillance for 'favourable' intermediate-risk disease is beginning to become more accepted, but clearly this is not recognised universally, and in England there is evidence of significant regional variation in how these cases are managed (28, 29).…”

Clinical impact of the Predict Prostate risk communication tool in men newly diagnosed with non-metastatic prostate cancer: a multi-centre randomised controlled trial

“…Unsurprisingly, decisional anxiety and regret are well-recognised issues for many newly diagnosed men (2). There is also significant regional variation in the proportion of men undergoing radical treatment, particularly for favourable intermediate-risk disease (3). Prognostic stratification is therefore vital in guiding management and treatment decision-making.…”