New prostate-cancer staging system may improve pretreatment prognostication

Reuters Health - 30/10/2020 - A pretreatment, predictive staging system for nonmetastatic prostate cancer, based on data analysis rather than expert consensus, promises to improve on existing risk-stratification systems, according to an international group of researchers.

"For over a decade, prostate cancer remains one of the few cancer types that do not routinely utilize the common stage-1-to-4 groupings that almost every cancer type uses to describe its prognosis," Dr. Daniel E. Spratt of the University of Michigan School of Medicine, in Ann Arbor, who worked on the study, told Reuters Health by email.

"Prostate cancer," he added, "has both national American Joint Committee on Cancer system (AJCC) and international Union for International Cancer Control (UICC) staging systems, but they fail to meet criteria put forth by staging committees to truly be valid. Furthermore, the prognostic systems we use in our national guidelines, such as National Comprehensive Cancer Network (NCCN) risk groups, have suboptimal performance."

The new analysis, in JAMA Oncology, involved data on more than 19,000 patients with cT1-4N0-1M0 prostate adenocarcinoma treated between 1992 and 2013.

Overall, 12,421 underwent radical prostatectomy and the remaining 7,263 received radiotherapy with or without androgen-deprivation therapy. Median follow-up was almost six years but more than 20% of patients were followed for at least 10 years.

Among factors considered when developing the scoring system were age, T category, N category, Gleason grade, pretreatment serum prostate-specific-antigen level, and proportion of positive core biopsies.

The system performed well across validation cohorts. In one validation set, predicted 10-year prostate-cancer-specific mortality ranged from 0.3% to 40.0%. The 10-year C index of the Score staging system (0.796) exceeded that of the AJCC 8th edition (0.757). This improved performance was evident across age, race, and treatment subgroups. The score system also showed superior performance in a second validation set.

"Thus," concluded Dr. Spratt, "an international consortium of over 60 practices created the first staging system for prostate cancer that not only is valid and meets all criteria to be used as a formal staging system, but it outperforms NCCN risk groups, Cancer of the Prostate Risk Assessment (CAPRA), and the expert opinion derived AJCC 8th edition of staging. This will help physicians better communicate and personalize their treatment recommendations."

Commenting on the findings by email, Dr. Yaw A. Nyame of the University of Washington, in Seattle, the co-author of an accompanying editorial, told Reuters Health, "The strength of this study is that it provides an easy-to-use clinical decision aid that was developed using contemporary data and evaluates a meaningful clinical endpoint in death from prostate cancer."

By David Douglas

SOURCE: https://bit.ly/37OptXN and https://bit.ly/3oxuWIp JAMA Oncology, online October 27, 2020



Posted on 30 October 20206 November 2020