Prostate cancer: delaying treatment of localized cancer would not increase its mortality

Prostate cancer delaying treatment of localized cancer would not increase

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    Michaël Peyromaure (urologist)

    Actively monitoring prostate cancer has the same high 15-year survival rates as radiation therapy or surgery, according to a large new trial. Results that give physicians and patients time to choose the right therapeutic strategy. The opinion of Pr. Michaël Peyromaure, head of the urology department at Cochin Hospital in Paris.

    Prostate cancer is the leading male cancer, with 50,000 new cases detected in France each year. A new study published at the European Association of Urology (EAU) congress in Milan may have an effect on cancer management: according to a trial conducted over more than 15 years in men diagnosed with cancer of the localized prostate, the choice of regular monitoring rather than recourse to radiotherapy or surgery, would not affect the vital prognosis over 15 years.

    A good prognosis at 15 years regardless of the method considered

    The ProtecT trial, commissioned by the universities of Oxford and Bristol, was conducted in nine UK centers to fully assess three major treatment options: active surveillance, surgery (radical prostatectomy) and radiotherapy with hormones for men with localized prostate cancer.

    Between 1999 and 2009, 1,643 men aged 50-69 across the UK who were diagnosed with localized prostate cancer after a PSA blood test agreed to be randomized to active surveillance ( 545), radical prostatectomy (553) or radical radiotherapy (545). The research team followed the men for an average of 15 years, to measure death rates, cancer progression and spread, and the impact of treatments on quality of life.

    Several lessons emerge:

    • About 97% of men diagnosed with prostate cancer survived 15 years after diagnosis, regardless of the treatment they received;
    • About a quarter of men on active surveillance had still not had invasive treatment for their cancer after 15 years;
    • Patients in all three groups reported a similar overall quality of life, in terms of general mental and physical health;
    • The negative effects of surgery or radiotherapy on urinary, bowel, and sexual function have been shown to persist for much longer than previously thought, up to 12 years.

    Lessons to be taken into account in the treatment

    What do these results tell us? First, that these treatment decisions after a diagnosis of low- and intermediate-risk localized prostate cancer need not be rushed, according to lead researcher Professor Freddie Hamdy of the University of Oxford. .

    “Clearly, unlike many other cancers, a diagnosis of prostate cancer shouldn’t be a cause for panic or rushed decision-making,” he said. “Patients and clinicians can and should take their time to weigh the possible pros and cons of different treatments knowing that it will not affect their survival.”

    Not to rush does not mean for all that refraining from intervening, but rather to weigh the pros and cons. In earlier findings published in 2016, researchers found that after ten years of follow-up, men whose cancer was actively monitored were twice as likely to see it progress or metastasize than those in other groups. However, the 15-year follow-up results show that this is not the case and that survival rates remain similarly high in all groups.

    Co-investigator Professor Jenny Donovan, University of Bristol, said: “Patients and doctors now have the information they need about the long-term side effects of treatments to better understand the trade-offs between their benefits and harms. Survival no longer needs to be considered when choosing treatment – because it’s the same for all three options.”

    However, flaws persist in the prediction

    The trial, however, highlighted flaws in current methods for predicting which prostate cancers are likely to grow quickly and spread. Initially, all of the people recruited for the trial were diagnosed with localized cancer, and 77% of them were judged to be low risk. A reassessment using more modern methods showed that a far greater number would now be considered at intermediate risk – and in around 30% of the men the disease had already spread beyond the prostate. This means that study participants had higher grade and stage disease than initially thought.

    A point also raised by Professor Michaël Peyromaure, contacted by Doctissimo, less enthusiastic and more cautious than the study, on the follow-up to be given to the proposed monitoring:

    “This article shows that choosing as initial treatment for localized prostate cancer a prostatectomy, radiotherapy, or simple monitoring, the death rate at 15 years is similar. However, if monitored, the risk of metastatic progression is doubled. The absence of an increase in deaths while metastases increase does not show that monitoring is equivalent to conventional treatment. Rather, it shows that certain treatments (hormone therapy, chemotherapy) make it possible to postpone death when the disease has progressed. It is also likely that with further hindsight, the increase in metastases will translate into an increased risk of death” he concludes.