Active monitoring, radical prostatectomy and radical radiotherapy in PSA-detected clinically localised prostate cancer: the ProtecT three-arm RCT

“[Abstract]
Objectives: To evaluate the effectiveness of conventional treatments for localised prostate cancer (active monitoring, radical prostatectomy and radical radiotherapy) in men aged 50–69 years.

Design: A prospective, multicentre prostate-specific antigen testing programme followed by a randomised trial of treatment, with a comprehensive cohort follow-up.

Setting: Prostate-specific antigen testing in primary care and treatment in nine urology departments in the UK.

Participants: Between 2001 and 2009, 228,966 men aged 50–69 years received an invitation to attend an appointment for information about the Prostate testing for cancer and Treatment (ProtecT) study and a prostate-specific antigen test; 82,429 men were tested, 2664 were diagnosed with localised prostate cancer, 1643 agreed to randomisation to active monitoring (n = 545), radical prostatectomy (n = 553) or radical radiotherapy (n = 545) and 997 chose a treatment.

Interventions: The interventions were active monitoring, radical prostatectomy and radical radiotherapy.

[..] Results: There were no statistically significant differences between the groups for 17 prostate cancer-specific (p = 0.48) and 169 all-cause (p = 0.87) deaths. Eight men died of prostate cancer in the active monitoring group (1.5 per 1000 person-years, 95% confidence interval 0.7 to 3.0); five died of prostate cancer in the radical prostatectomy group (0.9 per 1000 person-years, 95% confidence interval 0.4 to 2.2 per 1000 person years) and four died of prostate cancer in the radical radiotherapy group (0.7 per 1000 person-years, 95% confidence interval 0.3 to 2.0 per 1000 person years). More men developed metastases in the active monitoring group than in the radical prostatectomy and radical radiotherapy groups: active monitoring, n = 33 (6.3 per 1000 person-years, 95% confidence interval 4.5 to 8.8); radical prostatectomy, n = 13 (2.4 per 1000 person-years, 95% confidence interval 1.4 to 4.2 per 1000 person years); and radical radiotherapy, n = 16 (3.0 per 1000 person-years, 95% confidence interval 1.9 to 4.9 per 1000 person-years). There were higher rates of disease progression in the active monitoring group than in the radical prostatectomy and radical radiotherapy groups: active monitoring (n = 112; 22.9 per 1000 person-years, 95% confidence interval 19.0 to 27.5 per 1000 person years); radical prostatectomy (n = 46; 8.9 per 1000 person-years, 95% confidence interval 6.7 to 11.9 per 1000 person-years); and radical radiotherapy (n = 46; 9.0 per 1000 person-years, 95% confidence interval 6.7 to 12.0 per 1000 person years). Radical prostatectomy had the greatest impact on sexual function/urinary continence and remained worse than radical radiotherapy and active monitoring. Radical radiotherapy’s impact on sexual function was greatest at 6 months, but recovered somewhat in the majority of participants. Sexual and urinary function gradually declined in the active monitoring group. Bowel function was worse with radical radiotherapy at 6 months, but it recovered with the exception of bloody stools. Urinary voiding and nocturia worsened in the radical radiotherapy group at 6 months but recovered. Condition-specific quality-of-life effects mirrored functional changes. No differences in anxiety/depression or generic or cancer-related quality of life were found. At the National Institute for Health and Care Excellence threshold of £20,000 per quality-adjusted life-year, the probabilities that each arm was the most cost-effective option were 58% (radical radiotherapy), 32% (active monitoring) and 10% (radical prostatectomy).

Limitations: A single prostate-specific antigen test and transrectal ultrasound biopsies were used. There were very few non-white men in the trial. The majority of men had low- and intermediate-risk disease. Longer follow-up is needed.

Conclusions: At a median follow-up point of 10 years, prostate cancer-specific mortality was low, irrespective of the assigned treatment. Radical prostatectomy and radical radiotherapy reduced disease progression and metastases, but with side effects. Further work is needed to follow up participants at a median of 15 years.

[Plain English Summary]
Prostate cancer is the most common cancer in men and is often found through a blood test called a prostate-specific antigen test and through biopsies of the prostate. Over the years, these tests led to the detection of many small cancers that do not cause harm. Some prostate cancers are harmful, but it is difficult to recognise them early. When cancer is still inside the prostate, the conventional treatments are surgery or radiotherapy, which carry side effects including leaking urine and difficulty getting an erection, so another option is repeat investigations at regular intervals (active monitoring), with treatments given if the cancer progresses. These options needed to be compared in a study called a ‘randomised trial’ in which men agree to be allocated to one of the three treatments.

In the Prostate testing for cancer and Treatment (ProtecT) study, 200,000 men aged 50–69 years were invited to have a prostate-specific antigen test. Of the 82,849 men who agreed to be tested, 1643 of whom had prostate cancer that was still contained in the prostate agreed to be allocated to one of the three treatments. After an average of 10 years of follow-up, 99% of men were alive in each of the treatment groups. However, when compared with active monitoring, surgery and radiotherapy reduced the risk of disease spreading outside the prostate by half. Patients reported that urinary leakage and sexual function were worst with surgery, and sexual and bowel functions were affected by radiotherapy. Men on active monitoring had a gradual decline in their urinary and sexual function, particularly as around half of them later had surgery or radiotherapy. Radiotherapy was the treatment that seemed to be the best value for money. The findings from the Prostate testing for cancer and Treatment (ProtecT) study can help men make decisions about being tested and which treatment to have if they are found to have cancer within the prostate. We now need to find out the longer-term effects of these treatments on how long men live and their quality of life.”

Full article, Hamdy FC, Donovan JL, Lane JA et al. Health Technology Assessment 2020 August