Active monitoring for prostate cancer is as effective as radical treatment

By John Murphy, MDLinx
Published September 15, 2016

Key Takeaways

Men treated for localized prostate cancer—by radical prostatectomy, radiotherapy, or active monitoring—have equally high survival rates, according to a first-of-its-kind study published September 14, 2016 in The New England Journal of Medicine.

The researchers also found that patients treated with surgery and radiotherapy had lower incidences of disease progression and metastases—but a greater incidence of treatment-related side effects—than patients who were monitored.

“What we have learnt from this study so far is that prostate cancer detected by PSA blood test grows very slowly, and very few men die of it when followed up over a period of 10 years—around 1%—irrespective of the treatment assigned. This is considerably lower than anticipated when we started the study,” said lead investigator Freddie Hamdy, MBChB, MD, Professor of Surgery at the University of Oxford, in Oxford, UK.

“However, treating the disease radically, when found, reduces the number of men who develop spread of prostate cancer,” Dr. Hamdy added. “But we do not know yet whether this will make a difference to them living longer or better, and we have been unable to determine reliably which disease is lethal, and which can be left alone.”

This study, the Prostate Testing for Cancer and Treatment (ProtecT) trial, is the first to evaluate the effectiveness, cost-effectiveness, and acceptability of the three major treatment options. Between 1999 and 2009, researchers at nine centers in the UK recruited 1,643 men, ages 50 to 69, who were diagnosed with localized prostate cancer by PSA testing. The investigators randomized the men into three treatment groups: active monitoring (545 subjects), radical prostatectomy (553 subjects), and radical radiotherapy (545 subjects).

After an average of 10 years, the research team found that survival was extremely high among all subjects—approximately 99%—with no significant difference among the treatments. 

About twice as many men in the active monitoring group developed metastases (33) than those in the surgery group (13) or the radiotherapy group (16). Also, subjects in the active monitoring group had higher rates of disease progression (112) than men in the surgery group (46) or the radiotherapy group (46).

“Interestingly, we saw that disease spread was reduced by half in men who were assigned to radical treatment, but no difference in survival outcomes with either surgery or radiotherapy, and no progression of the disease in three quarters of the men in the active monitoring treatment group over the 10 years,” noted co-investigator David Neal, CBE, Professor of Surgical Oncology at the University of Oxford. “We need to continue to study these men to find out whether prevention of cancer progression by surgery or radiotherapy leads to better cancer control and survival in the longer term.”

An accompanying study assessed patient-reported outcomes and quality-of-life measures in ProtecT trial subjects. Problems with sexual function and urinary incontinence occurred most often in the prostatectomy group. Although some men recovered, these problems remained throughout the six years of this study. Bowel function was affected only in the men in the radiotherapy group, but recovered somewhat after six months. Nearly one-half of subjects who received active monitoring did not go on to radical treatment, and so avoided its side effects.

By the fifth year of the study, researchers observed no effects on anxiety, depression, general health status (mental or physical), or cancer-related quality of life in any treatment group.

The researchers also acknowledged that treatments and diagnostic techniques for prostate cancer have evolved in the two decades since the study protocol was first developed.

“Longer follow-up is now required to determine the ‘trade-off’ that patients need to make between cancer outcomes and quality of life, and further research to understand how we can distinguish lethal from non-lethal disease,” Dr. Hamby said.

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