Baseline Results of the UK Phase III ProtecT Trial of Active Monitoring, Radical Prostatectomy, or Radiotherapy for Localized Prostate Cancer
The UK phase III ProtecT trial is comparing the effectiveness of active monitoring, radical prostatectomy, and radiotherapy in men with localized prostate cancer. Lane et al have provided baseline results of the trial in an article in The Lancet Oncology.
Study Details
In the trial, men aged 50 to 69 years registered at 337 primary care centers in the UK were invited to attend a specialist nurse appointment for a serum prostate-specific antigen (PSA) test. Prostate biopsies were offered to those with PSA levels ≥ 3.0 μg/L. Patients with clinically localized prostate cancer were randomly assigned to active monitoring (surveillance strategy), radical prostatectomy, or three-dimensional conformal external-beam radiotherapy. Randomization was stratified by site, minimized for differences in participant age, PSA results, and Gleason score. The primary endpoint is prostate cancer mortality as assessed by an independent committee at a median 10-year follow-up; analysis in the intention-to-treat population is scheduled to occur in 2016.
Screening and Cancer Detection
Between October 2001 and January 2009, 228,966 men were invited to attend the appointment for PSA measurement; 100,444 (44%) attended the initial appointment, and 82,429 (82%) of those attending had a PSA test. PSA concentration was below the biopsy threshold of 3.0 µg/L in 73,538 (89%). Of the 8,566 men with PSA ≥ 3.0 µg/L (range, 3.0–19.9 μg/L), 7,414 (87%) underwent biopsies. Of these, 2,896 men were diagnosed with prostate cancer (4% of all tested men and 39% of those who had a biopsy), with 2,478 (86%) diagnosed at initial biopsy and 418 (14%) diagnosed after repeat biopsies. Of those diagnosed with cancer, 2,417 (83%) had clinically localized disease (mainly T1c, Gleason score 6) and were thus eligible for randomization, 270 (9%) had locally advanced, advanced, or metastatic disease, and 209 (7%) were excluded because of comorbidity.
Randomized Population
With the addition of 247 pilot study patients with localized disease recruited between 1999 and 2001, a total of 2,664 men were eligible for randomization. A total of 1,643 (62%) agreed to be randomized, with 545 randomly assigned to active monitoring, 553 to radical prostatectomy, and 545 to radiotherapy. The groups were generally balanced for age (median 62 years in each), PSA (median 4.6–4.7 µg/L), Gleason score (6 in 76%–78%, 7 in 20%–22%, 8–10 in 2%–3%), and clinical stage (T1c in 74%–79%, T2 in 21%–26%).
The investigators noted: “The ProtecT trial randomly assigned 1,643 men with localised prostate cancer to active monitoring, radiotherapy, or surgery. Participant clinicopathological features are more consistent with contemporary patient characteristics than in previous prostate cancer treatment trials.”
Freddie C. Hamdy, FMedSci, of University of Oxford, is the corresponding author for The Lancet Oncology article.
The study is funded by the UK National Institute for Health Research Health Technology Assessment Programme. For full disclosures of the study authors, visit www.thelancet.com.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
