Prostate cancer diagnosis
Prostate cancer diagnosis, From the age of 50, changes of the prostate occur in almost every second man. This can be a benign enlargement of the gland, the so-called benign prostatic hyperplasia (BPH). It has its starting point in that part of the prostate, which directly encloses the urethra. Gradually, the urethra is constricted, causing discomfort: the urine stream becomes weaker and the urge to urinate more frequently. BPH is mostly treated with drugs; But sometimes an operation is also necessary.
To investigate whether a BPH or malignant (malignant) change, that is to say cancer, is investigated various investigations are initiated.
As described in chapter “Early Detection”, the digital-rectal tracer is a simple procedure that detects the prostate carcinoma in approximately one-fifth of all patients. However, it is not suitable as the only diagnostic method since only carcinomas of a certain size can be found.
Due to their lack of reliability or lack of additional benefit for the initial diagnosis of prostate cancer, imaging methods are of only minor relevance. Therefore, they are only used in certain cases.
In the case of transrectal ultrasound (TRUS), the prostate and surrounding tissue structures can be visualized on a screen using an ultrasound probe, which is introduced into the rectum via the anus. The examination is painless but can be felt as unpleasant.
The TRUS is sometimes undertaken as a supplement to the probing, in order to determine the size, position and extent of a tumor more precisely. However, with respect to the cancer diagnosis itself, the method is not more reliable than the scanning examination alone.
An ultrasound examination of the kidneys is used to determine whether the urine discharge from the kidneys is already impaired as a result of cancer.
MRT and CT
Magnetic resonance tomography (MRI) and, more rarely, computed tomography (CT) can provide useful information on the prostate volume or localization of the suspicious area. This makes it possible, for example, to better estimate whether suspicious areas are present in the prostate, which therapy should be selected, and whether it can be operated with nerve-conserving surgery. In addition, enlarged lymph nodes can be detected, which can be indicative of lymph node metastases. If an irradiation is planned, an MRI can serve the exact planning of the target area. A MRI can also be sensible after a negative biopsy and still existing cancer suspicion.
Tissue collection (biopsy)
If the scan has a conspicuous result or if the PSA value is noticeably high, a biopsy can provide certainty as to whether or not prostate cancer is present. In this study, several tissue samples are taken from the prostate using a thin needle with ultrasound control via the rectum. This is done under local anesthesia; A hospital stay is not required. The tissue obtained is subsequently examined by a specially trained physician, the pathologist, for cancer cells under the microscope (histological examination).
A tissue collection by biopsy should be performed if one of the following criteria is present:
- PSA value of 4 ng / ml and above
- Cancer-suspected outcome in the digital-rectal examination (DRU)
- Conspicuous increase in the PSA value (without a change of the determination procedure)
Before performing the prostate biopsy, the patient must also be thoroughly informed about the benefits, risks and possible consequences of the investigation.
The histological examination of the tissue samples reveals within a few days whether a prostate carcinoma is present or not. The pathologist can also determine how aggressive a malignant tumor is.
If the PSA value and the result of the histological examination indicate an advanced disease or the patient has bone pain, various imaging methods are used in the context of the spread diagnosis.
- The skeletal scintigraphy serves the search for bone metastases.
- MRT and CT are used for the search for lymph node and other metastases and can be helpful if scintigraphy findings are unclear.
- The Oberbauch-Sonography (OBS) serves the exclusion of metastases in the liver.
- PET or PET / CT are only used in prostate cancer in exceptional cases or in studies.
Blood tests may also provide information on the stage of the disease. An increased concentration of the enzyme alkaline phosphatase (AP) and the calcium level can be indications of bone metastases. Also the level of the PSA value can give approximate indications of how far the disease has progressed. The higher the value, the higher the probability of the presence of metastases.