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Professor Christian Stief
Director of the Urological Clinic and Department, Grosshadern Campus, Munich University Hospital
In cases of prostate cancer, the use of active surveillance (or ’watchful waiting’) can delay or prevent entirely the need for a radical operation that – despite improved surgical techniques – can cause incontinence and impotence. It should not be underestimated, however, how stressful it can be knowing you have cancer but not actively doing anything about it.
The newly developed procedure of focal therapy for prostate carcinoma offers a third way: targeted elimination of the primary cancer in a way that leaves the organ intact and retains its function.
What type of patients are suitable for focal therapy as a non-aggressive means of treating prostate cancer?
Professor Stief: The same criteria apply as for the clinical trial on active surveillance: the PSA level should be no higher than 10 ng/ml; the Gleason score (a histological grading system indicating the stage of prostate cancer) should be no higher than six; a maximum of only three biopsies should return positive results; the prostate may only be of a certain size and no preliminary treatment of urethral stricture should have taken place – all these criteria indicate the presence of a localised and slow-growing prostate tumour. An MRI scan is also carried out to determine the precise size and location of the tumour. The data for all European hospitals participating in the study is evaluated centrally by a team of highly regarded experts. If the patient proves suitable for focal therapy, the tumour is identified and can then be removed with pinpoint precision.
How is the therapy performed?
Professor Stief: The actual therapy is performed on an inpatient basis involving a single overnight hospital stay. On the day before the operation, the patient is seen by the anaesthetist; on the day of treatment itself, the approx. 90 minute operation is carried out under general anaesthetic. During the operation, a substance is delivered to the tumour that can be activated by a laser, completely destroying the blood vessels that supply nutrients to the tumour. This causes a circumscribed tissue defect that will ideally encompass the entire primary cancer. The patient is then able to leave the hospital the same day after only a short stay in the recovery room.
What are the side effects of the therapy?
Professor Stief: Patients usually report only minor or moderate complaints such as a burning sensation while urinating and/or a more frequent need to urinate for a few days after the operation. In exceptional cases, patients have difficulty urinating and have to be temporarily fitted with a catheter. Continence and potency are unimpaired and the patient can return to work just one day after treatment.
How is the success rate of the treatment monitored?
Professor Stief: The patient must be continually monitored as part of the treatment and should return to us for a check-up every three months for a period of two years. Monitoring PSA levels after the operation tells us less because the bulk of the PSA-producing prostate tissue is preserved. Cross-sectional imaging is the most important tool for evaluating the post-operative situation (MRI: after a week, after 12 and 24 months). A punch biopsy is carried out after one year and again after two. The data gathered in the phase II clinical trial (40 patients) is extremely encouraging: in all cases in which at least 80 per cent of the target volume that was treated is shown to have declined in the post-operative crosssectional imaging, there have been no cases of remaining tumour tissue. Continence and potency are also completely preserved. Should there be evidence of remaining tumour tissue, options include further focal therapy, traditional radiotherapy and radical surgery.