Choosing treatment for localised prostate cancer: what each option costs

This is the most genuinely open decision in common cancer, and the reason it is open is that ProtecT measured both sides of it in the same men.

The cancer control side. ProtecT randomised 1,643 men with PSA-detected localised prostate cancer to active monitoring, prostatectomy or radiotherapy with hormones. At a median 15 years, death from prostate cancer had occurred in 45 of 1,643 men (2.7 percent): 17 (3.1 percent) under monitoring, 12 (2.2 percent) after surgery and 16 (2.9 percent) after radiotherapy, p=0.53 for the overall comparison. Death from any cause occurred in 356 men (21.7 percent), similar in all three groups. More than a third of the men had intermediate-risk or high-risk disease at diagnosis, so this is not a trial of trivial cancers.

What treatment does buy is control of spread. Metastases developed in 51 monitored men (9.4 percent) against 26 (4.7 percent) after surgery and 27 (5.0 percent) after radiotherapy; long-term androgen deprivation was started in 69 (12.7 percent), 40 (7.2 percent) and 42 (7.7 percent); clinical progression occurred in 141 (25.9 percent), 58 (10.5 percent) and 60 (11.0 percent). And 133 monitored men (24.4 percent) were alive at the end of follow-up having never had any prostate cancer treatment at all.

The cost side, from the same trial's patient-reported outcomes over 6 years. Prostatectomy had the greatest negative effect on sexual function and urinary continence, and although there was some recovery, both stayed worse in the surgery group throughout. Radiotherapy's effect on sexual function was worst at 6 months and then partly recovered and stayed stable; it had little effect on urinary continence. Bowel function was worse after radiotherapy at 6 months and then partly recovered, except that bloody stools became more frequent over time. Sexual and urinary function declined gradually under active monitoring too, because men age. No differences were seen between groups in anxiety, depression or general health-related quality of life.

PACE-B put five-year numbers on modern radiotherapy specifically. At 5 years, 64 percent of men after stereotactic body radiotherapy and 69 percent after conventional radiotherapy were leak-free, 91 and 90 percent were pad-free, and 6 and 4 percent reported moderate or big urinary leakage problems. Erections adequate for intercourse fell from 35 to 17 percent after stereotactic radiotherapy and from 40 to 20 percent after conventional radiotherapy.

How to use all this. If the cancer is CPG 1, the evidence supports doing nothing but watching, and about a quarter of monitored men in ProtecT never needed treatment. If it is CPG 2 or 3, surgery and radiotherapy have the same cancer outcome and different side-effect shapes: surgery front-loads incontinence and erectile dysfunction, radiotherapy spreads bowel and urinary symptoms out and needs hormone therapy added. If it is CPG 4 or 5, the question is no longer whether to treat but how hard, and the androgen deprivation duration trials answer that.