Millions of men worldwide suffer from prostate cancer. In Germany, most prostate cancer patients are treated in the Martini Clinic Hamburg. There, doctors have the highest level of experience with this type of cancer. Here is an interview with private lecturer Dr. Tobias Maurer who works there.
Clinic Compass: Why is prostate cancer so common in Germany? What are the causes of this disease?
PD Dr. Tobias Maurer: As it is a multifactorial process, the causes are not known. Age is a key factor. If patients are diagnosed at a very young age, genetic predisposition can be a reason.
Clinic Compass: In what way does the diet play are role in the disease?
PD Dr. Tobias Maurer: A meat-based diet rich in carbo-hydrates can promote disease. However, it is difficult to trace back a disease to the diet for a 60 year old patient with a prostate carcinoma. It is also very hard to record one’s diet over a longer period of time. Sometimes you don’t know yourself what you ate two weeks ago. However, a healthy lifestyle has a protective effect.
Clinic Compass: Patients often have to choose between surgery and radiotherapy. Which method would you recommend for a patient with a Gleason Score of 7a, an increased level of PSA and a locally limited prostate carcinoma?
PD Dr. Tobias Maurer: The most important aspect is the patient’s overall situation. How old is he? Is he in a good physical condition? Does he have any accompanying illnesses? Aspects to consider here are: Is active surveillance an option? In some records, active surveillance is applied for patients with a Gleason Score of 7a. However, if the patient is 77 years old and suffering from heart condition, we probably don’t have to do anything. Also, the development of the PSA level indicates the severity of the disease. Then, it depends on how many biopsies are affected. In general, I would say: If a patient is in a good condition and does not have any severe accompanying illnesses as well as a prostate carcinoma with a Gleason Score of 7a in several biopsies, then he should not get any active therapy like surgery or radiotherapy.
Comparing radiotherapy with surgery, the difference is that after surgery, a histological evaluation is available. You know what the deal is. In radiotherapy, you don’t know that. Also, the PSA level only has to fall below the detection limit after surgery, in contrast to radiotherapy. Thus, patients that had an operation often have a better conscience. Of course, surgery can also have side effects. If the surgery is done very well, for organ-confined tumors there is no big risk of incontinence anymore today. There are continence rates of far above 90 percent after three months. But this is different for potency. It is possible that the relevant nerves are damaged during the surgery, but this also applies for radiotherapy in the long run.
Clinic Compass: What do you think about treatment using High Intensity Focused Ultrasound? How would you rate this kind of focal therapy?
PD Dr. Tobias Maurer: The tumor can be localized in the prostate much better with modern imaging processes and a targeted fusion biopsy, which is used more and more often. However, I still take a critical view on these proceedings. Unlike a renal tumor which generally grows in a round shape and develops a pseudo-capsule, the prostate is a gland organ. These glands are branched like a tree with very small ramifications. The cancer cells grow along these tubular glands and are thus branched as well. The proponents of a focal therapy say: We treat the significant tumor, the tumor which is important for the patient. But the small metastases can also contain significant, malignant components which cannot be localized as easily. Looking at the follow up when a focal therapy is applied, I think that the outcome is sobering. In accordance with the guidelines, focal types of therapy should only be considered for patients that are apt for both active surveillance and active therapy. In general, I am rather critical of focal therapy, because my understanding is that for the prostate, there is no demarcated tumor development.
Clinic Compass: Only recently, radioactive substances are used for a better treatment of prostate cancer patients. With the PSMA-radioguided surgery, small metastases can be detected due to their radioactive radiation. How would you rate this method?
PD Dr. Tobias Maurer: First, I would like to say something about positron emission tomography. Tumor metastases can be made visible with the help of small radioactively labeled particles that are directed against the prostate-specific membrane antigen (PSMA). With this method, tumor centers can be detected much earlier and more precisely than using MRT or CT. This allows for a more precise treatment. First, these tracers could only be used for imaging, namely for the positron emission tomography. For some years now, these tracers can also be used for surgery in a modified form. Before surgery, the patients get an injection of a radioactive substance. With the help of a gamma detector, which is similar to a Geiger counter, the small tumor centers can be detected and safely resected. However, it is also important to mention that none of these methods is one hundred percent perfect. We will not detect the single tumor cell with this process. But it is definitely better than it used to be when we only operated based on the pictures.
Clinic Compass: For prostate surgery, the Da Vinci Surgical System is often used. The S3 medical guideline for prostate cancer states that to date, no study has been able to prove that surgery with the Da Vinci robot are more efficient than the classic open surgery. Why is the Da Vinci robot used anyway?
PD Dr. Tobias Maurer: It may be that patients can be discharged a little bit earlier and they only have small incisions – this is also about cosmetics. Blood loss is a little lower and the urinary catheter can usually be removed earlier. Eventually, it is also more comfortable for the surgeon to sit at a console than to operate standing at the table. But you are right, there is only one prospective trial from Australia on this subject. It revealed that there is no significant difference concerning the oncological outcome and the rates of continence and potency. At the Martini Clinic, we do not see any decisive advantage here, either.
Clinic Compass: Was there a personal highlight in your career as an urologist?
PD Dr. Tobias Maurer: I can remember very well when we examined the first patient with a PSMA-PET in 2012. That was as if someone switched on the light. I still get goosebumps when I think about it. In that moment, we realized that there was a sudden change in prostate cancer medicine.
Dr. Maurer, thank you for the interview!
PD Dr. Tobias Maurer is a specialist for Urology and Senior Physician at the Martini-Clinic of the University Hospital Hamburg-Eppendorf. Before, he worked as Chief Physician at the Clinic and Polyclinic for Urology of the Technical University of Munich, Rechts der Isar Hospital.