Prostate cancer therapy

Possible therapies

Depending on the time of diagnosis and the extent of the tumor, as well as patient-specific factors such as age and previous illnesses, prostate tumors are treated with surgery, radiotherapy, chemotherapy or hormone therapy. Sometimes a combination of these treatments is also necessary. For localized prostate cancer, surgery and radiotherapy are the two curative treatment options in line with the guidelines.

Active surveillance

In patients whose prostate cancer is small, very slow growing, has a low histologic grade of cancer cell differentiation (Gleason Score), and does not cause symptoms, the tumor is often only monitored regularly. This means that the patient comes to the clinic for close-meshed control examinations, where the PSA level is monitored and imaging diagnostics (ultrasound, magnetic resonance imaging) and tissue sampling from the prostate (control biopsies) are performed regularly. No specific treatment is given. This active monitoring is called “active surveillance” (watch and wait).

Surgery

In a procedure called prostatectomy, the entire prostate gland is surgically removed. There are various surgical techniques for this, including surgery with the robot, which is used as standard at the USZ. We use the latest Da Vinci technology as a surgical system for this purpose. Here, the operation is performed endoscopically, i.e. minimally invasive through several small incisions and with the help of thin special instruments. As far as possible, “nerve-sparing” surgery can be performed to reduce side effects such as impotence and incontinence.

Irradiation

Radio-oncology uses high-energy X-rays, which are focused inside the body in the prostate and prostate cancer and specifically kill it. Radiation is carried out “from the outside” using so-called linear accelerators, does not require surgery or anesthesia and can be integrated into everyday professional and private life as an outpatient therapy. At the USZ we use a highly precise form of radiotherapy that is unique in Switzerland and is completely MRI-guided: most patients can therefore be treated with just 5 outpatient therapy sessions. With this stereotactic technique, prostate cancer in the intermediate risk group can be cured in >95% of patients and at the same time >90% of all patients remain without relevant side effects. In the case of aggressive prostate cancer, the best survival rates are achieved with a combination of radiotherapy and modern anti-hormone therapy. Radiation can also prolong the survival of metastasized cancer or prevent or alleviate symptoms caused by the cancer.

High Intensity Focused Ultrasound (HIFU)

With this focal therapy, the tumor is destroyed in a targeted and gentle manner without affecting the surrounding tissue. The prostate remains as a functioning organ. In HIFU treatment, ultrasound waves heat the tumor tissue to 90 degrees Celsius and ” boil away” the cancer cells in the prostate. The ultrasound waves are very precisely bundled (focused) in one place and destroy the tumor focus with millimeter precision. This procedure can be used for localized moderately aggressive prostate cancer. HIFU is particularly gentle in comparison and has a lower risk of side effects such as unwanted urinary leakage (incontinence) or erectile dysfunction (impotence).

Hormone therapy

Technically correct terms are anti-hormone therapy, hormone deprivation therapy or hormone deprivation treatment. In order to grow, prostate cancer cells need male sex hormones, so-called androgens such as testosterone. Hormone deprivation therapy attempts to withdraw these hormones from the cells through medication and thus stop the progression of the cancer. It is important to note that hormone deprivation therapy alone can often slow down tumor growth in prostate cancer for years, but a cure is not possible.

Various drugs with different modes of action are available for anti-hormone therapy and are used as injections or in tablet form. There are medications that lower testosterone levels in the blood. Other drugs prevent the growth-promoting effect of testosterone on cells; however, they do not affect the concentration of testosterone in the blood.

Since testosterone is produced in the testicles, it is also possible to lower hormone levels by surgically removing the testicles (orchiectomy). However, this procedure is irreversible, unlike regular medication.

Chemotherapy

As with other types of cancer, chemotherapy (cytostatic drugs) for prostate tumors is intended to cause the cytostatic drugs to prevent the cancer cells from dividing. This can slow or stop the growth of prostate cancer. Chemotherapy is given in addition to anti-hormone therapy in the metastatic stage. It is the drugs docetaxel and cabazitaxel that can be administered.

PARP inhibitors

In some patients, the tumor cells have a specific change in the genes, known as a BRCA mutation. Patients with metastatic disease who have this alteration can receive targeted therapy with so-called PARP inhibitors (drug olaparib).

Lutetium PSMA ligand therapy

This is a form of treatment for patients with a metastatic tumor. Here, a radioactive substance is injected, which is transported to the tumor cell via a carrier and thus specifically kills the tumor cell.

Cancer cells originating from the prostate usually carry prostate-specific membrane antigen (PSMA) on the cell surface. PSMA is present in small amounts on the surface of healthy prostate cells, but much more on cancer cells. Like a magnet, the PSMA serves as a docking site for the carrier that transports the radioactive therapeutic substance (lutetium-177). The therapeutic substance travels via the bloodstream directly to the tumor tissue and leads to targeted irradiation of the malignant cells.