The PSA test is not a reliable indicator of cancer and for these reasons its use in the diagnosis of prostate cancer is controversial.
WHAT ARE THE FACTORS THAT CAN AFFECT THE TEST RESULTS?
- recent ejaculation
- digital rectal examination
- transrectal ultrasound
- diagnostic procedures (e.g. cystoscopy)
Trauma due to cycling or driving a motorbike
IS THIS BECAUSE THE PSA IS NOT A MARKER FOR THE PRESENCE OR ABSENCE OF MALIGNANCY?
- About 20% of prostate cancers diagnosed by biopsy were detected in patients with "normal" PSA values;
- The values of PSA can be elevated even in the presence of prostatitis or benign prostatic hypertrophy;
- There may be small changes in PSA for reasons that are unclear but, definitely, not pathological.
In contrast, in men who have already been treated for prostate cancer, a PSA test performed to monitor the evolution of the disease it is very useful tool to evaluate the effectiveness of therapy; in fact after the treatment the PSA level returns to within the normal range in a time that varies according to the treatment received.
The severity of the tumor is defined by two parameters, the grading and the stage of disease.
GRADING
The pathologist who receives the tissue taken by biopsy and which is analyzing under the microscope, can not only determine whether cancer cells are present, but can also define the grading. The grading, the degree of differentiation of tumor cells, is related to aggressiveness of the tumor, and indicates the speed with which the mass tends to grow and spread to other organs.
- A score of 2 to 4 indicates a well-differentiated tumor growth and with little tendency to spread to other organs;
- A score of 5 to 6 indicates a moderately differentiated tumor with an intermediate degree of aggressiveness;
- A score of 7 to 10 indicates an aggressive cancer poorly differentiated and more likely to spread to other organs.
STAGING
The other factor used for the evaluation of prostate cancer is the stage of disease. The staging is used to define the location and size of the tumor: it also indicates whether the disease has spread to other organs. The method employed to describe the stage of the tumor disease, for all tumor types, is the so-called TNM system, where the letter T indicates the extent of the primary tumor, the letter N identifies the involvement of the lymph nodes, while the letter M records the presence of distant metastases.The TNM letters are complemented by a number. The T1 and T2 tumors are called 'localized', while the T3 are 'locally advanced'. When a cancer has reached the lymph nodes or other organs is called 'advanced' or 'metastatic'.
In relation to the histological features of the tumor and the values of PSA, the risk classes are defined to guide the therapeutic choice. Beside the definition of grading, indicating the degree of differentiation of cancer cells, and the stage of the disease, which defines the extent of the tumor, over the years it has become increasingly important to pay attention to the concept of risk of disease progression. The definition of the class of risk makes it possible to relate the 'extent of the tumor', based on the staging of the disease, with the values of PSA and Gleason grading. This definition will guide the oncologist in selecting the most appropriate therapy.
various classes of risk have been identified:
- low risk
- intermediate risk
- high risk
The definition of risk classes is based on the Staging (defined using the TNM system), the grading (defined by Gleason score) and levels of PSA.
Localized disease means that the tumor is limited to the prostate.
Locally advanced means that the tumor has spread outside of the prostate.
