Staging Prostate CancerIf you have been diagnosed, it is helpful to know how large how large the tumor is and where it is located. Also good to know how far it has spread Depending on its size and spread, your doctor will stage your tumor. Information on your tumor stage, along with tumor grade and PSA level, is an important consideration in choosing treatment and to predicting a cancer free life. Tumor stages are: Localized
Stage I or A or T1: a tumor that cannot be felt (nonpalpable). Stage II or B or T2: a tumor that can be felt (palpable) but is confined to the prostate gland. Regional
Stage III or C or T3: a tumor that has grown through the prostate capsule, perhaps into the seminal vesicles. T4: a tumor that has grown into nearby muscles and organs. Metastatic
Stage IV or D and N+ or M+: tumors that have metastasized to the regional (pelvic) lymph nodes (N+) or more distant parts of the body (M+). | One of two widely used staging systems, known as TNM, evaluates Tumor size and spread, cancer in the nearby lymph Nodes, and whether the cancer has established distant Metastases. The second system measures the same tumor characteristics, but uses an ABCD rating. |
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Each of these stages is subdivided into more precise categories (see Staging Systems, above). In 1990, two-thirds of newly diagnosed prostate cancers in the United States were Stage I or II (clinically localized). Slightly more than 10 percent were Stage III (regional), while about 20 percent were Stage IV (metastatic). The main tests used for clinical staging of prostate cancer are DRE, PSA, and transrectal ultrasound (TRUS). Bone scans may be used when distant metastases are suspected. The digital rectal exam (DRE), a procedure in which the doctor inserts a gloved finger into the rectum to examine the rectum and prostate to look for an irregular or abnormally firm area, helps to gauge tumor size, and it may show if the cancer has spread into nearby tissues. PSA tests are playing an increasingly common role in cancer staging. Elevated PSA levels in the blood correlate roughly with the volume of cancer in the prostate, with the stage and grade of the tumor, and with the presence or absence of cancer metastases or growths in other tissues. (For more about PSA, see Understanding Prostate Changes: A Health Guide for All Men .) Valuable information about tumor size and location can also be obtained from TRUS used to guide the biopsy in sampling abnormal areas of the prostate. TRUS uses an ultrasound probe inserted in the rectum to visualize the area on a screen. The pathologist's evaluation of the biopsy samples also helps to establish the clinical stage (size and extent) of a cancer. The pathologist tallies how many of the tissue samples contain cancer, notes whether any of the samples are more than half cancerous, and determines a Gleason score. When clinical staging suggests that cancer has spread to the lymph nodes or beyond, radionuclide bone scans can be used to look for metastases to bone, a common site of prostate cancer spread. However, research now shows that patients with PSA levels of 10 ng/ml or less, without bone pain, are so unlikely to have bone metastases-regardless of tumor stage or grade-that doctors often recommend that these patients can skip the bone scan. Sophisticated imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI) can also help to uncover distant metastases. Like bone scans, however, such tests may be unnecessary for some men. Recent studies indicate that when prostate cancer is clinically localized -the situation for two-thirds of newly diagnosed cases-CT and MRI add little to the information available through DRE, PSA, and TRUS. | The higher a man's PSA level, the more likely that cancer could be in the picture. During screenings in men ages 50 or older, 85 of every 100 men in the United States will have normal PSA levels (4 ng/ml or below). Among the remaining 15 men, only 3 will have biopsies that show cancer. Some recent refinements designed to make PSA testing more accurate and more precise are under clinical study. For instance, PSA density relates a man's PSA level to the size of his prostate, which can be estimated through ultrasound. PSA velocity is based on changes in PSA levels over time; a sharp rise from a baseline level raises the suspicion of cancer. |
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