Usually, to detect a prostate cancer, very specific tests are performed: digital rectal exam (DRE), prostate-specific antigen (PSA) test, transrectal ultrasound (TRUS) and biopsy.
Digital rectal exam (DRE) – a rectal examination is a painless palpation of the posterior abdomen and the organs in it. During the procedure, your doctor will introduce a glove finger in your anus to search for abnormalities such as inflammation. Gently, your physician will inspect the lining of your rectum, trying to:
- detect abnormal tissue growth on the surface of the rectum;
- specify exactly where the tumor is located
- assess the size, volume and appearance of the tumor
- Determine if the tumor can move or if it is fixed to the wall of the rectum.
Prostate-specific antigen (PSA) test – prostate specific antigen is a protein produced exclusively by the prostate. It plays two major roles: 1) liquefying the semen to facilitate the movement of sperm; 2) helping to dissolve the cervical mucus to facilitate the entry of sperm. The PSA is present in the blood of all men; however, high rates, between 4 and 10 ng/ml are often associated with benign prostatic hyperplasia (BPH) or prostate cancer. Though not fully accurate, the PSA test is an important tool in detecting early prostate cancer.
Transrectal ultrasound – this imaging technique is often used in the prostate cancer diagnosis. Itconsists of using inaudible sound waves produced by a probe inserted into the rectum to create an image of organs in the pelvis. Ultrasound images are captured in real time; therefore, your doctor is able to visualize movements of organs and tissues of the pelvis. An ultrasound of the prostate is used to detect possible problems in the prostate gland, and indicate whether the prostate gland is enlarged or if it is occupied by a cancerous tumor.
Biopsy – although other diagnostic techniques can be used to reveal a prostate cancer, a biopsy is usually required to accurately confirm the disease. In fact, a prostate biopsy is the only test that can affirm the presence or absence of cancerous cells inside the prostate gland. Usually, a prostate biopsy consists of removing cells or tissues from the prostate gland to examine under a microscope. Indeed, analysis of samples under a microscope can distinguish benign tumor from malignant tumor (cancer).
There are many types of biopsies that can be performed in prostate cancer diagnosis. The type of biopsy practiced depends on the size or the location of the tumor. However, whatever the method used, it must be done carefully so it does not promote the spread of cancer cells into healthy.
Bone scan – this imaging technique allows your doctor to visualize your bone and detect very early abnormalities, sometimes not even visible on routine X-rays. During the procedure, the specialist will inject a small amount of radioactive material (radiotracer) into a vein which will bind to the diseased bone. The radiation emitted is detected by a gamma camera that creates picture of the skeleton. The purpose of this test in prostate cancer diagnosis is to determine if the cancer has spread to any bone in your body.
Ultrasound – this painless imaging technique uses high-frequency sound waves to visualize various organs in your body including the prostate gland. In the diagnosis of prostate cancer, it involves applying an ultrasound sensor (transducer) on your upper abdomen in order to obtain images of the prostate. The transducer emits sound waves through the tissues of the prostate gland, which then return as an echo. The echo is then collected and analyzed by a computer system that transmits a live image on a video screen.
CT scan – a scanner is the use x-rays to form images of the internal organs. It can detect abnormalities not visible on standard x-rays or ultrasound. A CT scan allows not only the diagnosis but also highlighting of lymph nodes or liver metastasis.
Magnetic resonance imaging (MRI) – an MRI with contrast injection allows your health care provider to visualize organs of the inside of your body. In the case of prostate cancer, it can analyze the structure of your prostate gland to search for abnormalities: inflammation, abnormal tissue growth, etc. In addition, MRI allows your doctor to determine the exact size and extent of the tumor in your prostate gland.
Lymph node biopsy – a lymph node biopsy is a recent surgical intervention used in the diagnosis of prostate cancer. During the procedure, samples of lymph nodes are collected for laboratory analysis to determine if the cancer has spread to nearby lymph nodes. In general, one or more lymph nodes closed to your prostate are removed. This test is recommended if the MRI or CT scan has revealed enlarged lymph nodes.