Table of Contents
What is Prostate Cancer
Prostate Cancer is a malignant (cancerous) tumor that arises from the glandular tissue of the PROSTATE GLAND, a walnut-size structure that encircles a man’s URETHRA at the base of the BLADDER. Prostate cancer is one of the HORMONE-DRIVEN CANCERS that appears to have some genetic foundations as it tends to run in families. Prostate cancer also strongly correlates to increased age; it is rare among men under age 50 and affects more than half of men over age 70.
Prostate cancer is the most frequently diagnosed cancer among men in the United States and is primarily found in men over age 60. Though prostate cancer may take an aggressive path with widespread METASTASIS that leads to premature death, prostate cancer more often than not is a slow-growing cancer and runs a course that doctors can control through various treatments. Far more men die with prostate cancer than from prostate cancer. With early detection and treatment, prostate cancer may be curable.
The symptoms of prostate cancer are often difficult to distinguish from the symptoms of noncancerous conditions that affect the prostate gland, particularly BENIGN PROSTATIC HYPERPLASIA (BPH). All men eventually develop some degree of BPH as they grow older, enlargement of the prostate gland begins to occur as a natural dimension of aging. However, BPH is not and does not become prostate cancer, though a man may have both conditions concurrently.
Symptoms of Prostate Cancer and Diagnostic Path
Early to moderately advanced prostate cancer may cause no symptoms, with diagnosis resulting from further investigation of an abnormally high PROSTATE-SPECIFIC ANTIGEN (PSA) BLOOD level or abnormal findings during DIGITAL RECTAL EXAMINATION (DRE) performed during a ROUTINE MEDICAL EXAMINATION. When symptoms are present they may include
- frequent URINATION, particularly at night (NOCTURIA)
- incomplete emptying of the bladder with urination, sometimes resulting in URINARY URGENCY, URINARY FREQUENCY, and URINARY TRACT INFECTION (UTI)
- reduced urinary flow, urinary hesitation (difficulty starting the flow of urine), and dribbling (difficulty stopping the flow of URINE)
- blood in the urine (HEMATURIA) or SEMEN (hematospermia)
- sensation of heaviness or fullness in the lower abdomen (pelvic area)
- low BACK PAIN or rectal pressure
The diagnostic path may include DRE to palpate the prostate gland, blood tests to measure PSA levels and detect the presence of other TUMOR MARKERS, urinalysis, transrectal ULTRASOUND (TRUS), and biopsy (multiple tissue samples) of the prostate gland.
STAGING AND GRADING OF CANCER are critical for identifying and selecting the most appropriate treatment options. Several systems exist for cancer staging and grading. Because prostate cancer cells typically invade different areas of the prostate gland at varying levels of what pathologists call architectural disorder—the extent to which the cell structure deviates from normal—conventional staging and grading methods often cannot accurately classify the prostate cancer overall. Some areas of invasion may be fairly advanced and others minimally involved. The Gleason system and the Jewett system are methods unique to prostate cancer and the ones most doctors use to guide treatment decisions. In addition, conventional staging methods provide further classification.
Gleason pattern and score
The Gleason system allows the pathologist to select the pattern (sometimes called grade) of the two most predominant architectures (primary and secondary) among the biopsy samples and combine them into a score that represents the character of the prostate cancer overall. There are five patterns and nine scores possible within the Gleason system. The lower the Gleason score (also called the Gleason sum), the more likely the cancer is confined and will respond to treatment. However, the patterns that establish the score are also important. For example, a prostate cancer that has a Gleason score of 7 coming from 3 + 4 has a more positive prognosis than one with a Gleason score of 7 coming from a 4 + 3 because the first number indicates the primary pattern and pattern 3 is less aggressive than pattern 4. It is important to know both patterns as well as the score.
|GLEASON PATTERNS AND SCORES FOR PROSTATE CANCER|
|pattern 1||cells and architecture nearly normal (well differentiated)|
|pattern 2||cells nearly normal though glandular cells beginning to invade MUSCLE tissue within the PROSTATE GLAND|
|pattern 3||cells still maintain glandular structure though invasion of muscle tissue within the prostate gland is significant; possible regional METASTASIS|
|pattern 4||significant cell abnormality with loss of normal architecture and distorted glandular structure; probable regional metastasis; possible distant metastasis|
|pattern 5||cells and architecture completely irregular and abnormal (undifferentiated); probable distant and multiple metastases|
|2||lowest possible score; very early cancer with excellent prognosis|
|3 to 4||slow growing tumor; early cancer with good prognosis|
|5 to 6||mildly aggressive tumor likely confined to the prostate gland|
|7||moderately aggressive tumor with possible regional metastasis|
|8 to 9||aggressive tumor with regional metastasis|
|10||highly aggressive tumor with multiple distant metastases|
Jewett staging system
The Jewett system, also called the Jewett-Whitmore system, assigns four alphabetic values to the extent of cancer metastasis, with numeric subvalues for more precise classification.
|JEWETT STAGING SYSTEM CLASSIFICATIONS|
|stage A||very early, localized cancer; only indication is elevated BLOOD PROSTATE-SPECIFIC ANTIGEN (PSA) level|
A1: well-differentiated or single site within PROSTATE GLAND
A2: clearly abnormal cells or multiple sites within prostate gland
|stage B||localized cancer palpable via DIGITAL RECTAL EXAMINATION (DRE); may cause mild symptoms|
B1: single site
B2: multiple sites
|stage C||METASTASIS to adjacent tissue but not to LYMPH nodes|
C1: tumor is outside the prostate gland but nonobstructive
C2: tumor obstructs the BLADDER or the URETHRA (urinary symptoms)
|stage D||metastasis to lymph nodes or distant organs|
D1: regional LYMPH NODE involvement
D2: distant lymph node or organ involvement (including BONE)
D3: RECURRENCE after treatment
Some doctors additionally use conventional staging and grading systems to further classify and understand the prostate cancer’s characteristics to optimally tailor treatment approaches. The two main conventional staging systems are
- the numeric system, which identifies five levels of tumor aggressiveness (stage 0 through stage 4, or IV)
- the American Joint Committee on Cancer (AJCC) tumor, node, and metastasis (TNM) system, which assigns numeric values to the size of the tumor, invasion of LYMPH NODES, and spread to distant organs or structuresJewett staging system classificationsProstate Cancer Treatment Options and Outlook
The treatment of choice for men under age 70 is nearly always PROSTATECTOMY, a surgical OPERATION to remove the prostate gland, with adjuvant (follow-up) CHEMOTHERAPY, RADIATION THERAPY, or HORMONE THERAPY as appropriate. Radiation therapy is most effective when the cancer remains confined to the prostate gland. For men over age 70, in whom prostate cancer is likely to be slow growing and remain localized, the doctor may recommend less invasive approaches such as diligent monitoring (watchful waiting) or radiation therapy (external beam or internal seeding).
No matter his age at the time of diagnosis, a man must consider the many factors that contribute to the relative benefits and risks of treatment options for his stage and grade of cancer, prognosis, other health conditions, and personal desires. Treatments such as surgery and hormone therapy may affect sexual function and have other undesirable side effects. It is important to fully understand the potential implications of treatment options and their effects on QUALITY OF LIFE. Though prostate cancer is the second-leading cause of cancer deaths among men in the United States (LUNG CANCERbeing first), treatment provides long-term management and prostate cancer is not fatal in the majority of men who develop it.
Risk Factors and Preventive Measures
The most significant risk for prostate cancer is age. Prostate cancer is uncommon in men under age 50 though is present in about half of men over age 80. Other factors that increase the risk for prostate cancer are African American heritage and longterm EATING HABITS that feature foods high in saturated fat. There is some evidence that dietary consumption of SOY proteins, such as in soybeanbased foods and in nutritional supplement products, and LYCOPENE, found in tomatoes and pink grapefruit, improve the ability of prostate glandular cells to resist cancerous changes. The medicinal botanical product SAW PALMETTO, available in the United States as a nutritional supplement, may help maintain overall PROSTATE HEALTH.
Health experts differ in their opinions about the value of routine screening procedures, such as DRE and PSA blood levels, for detecting prostate cancer and especially for improving the outcome of treatment. PSA in particular tends to generate a high percentage of false-positive findings, thrusting men into more invasive diagnostic procedures that have increased risks as well as heightened emotional stress. However, both DRE and PSA are components of a routine medical examination in the United States for men over age 50. It is important for a man and his doctor to carefully and comprehensively evaluate all aspects of the man’s personal prostate health and to weigh the risks and benefits of further diagnostic assessment.