Prostate cancer

Anatomy of prostate gland

The prostate gland is roughly the size of a walnut (height 30mm, width: 40mm, thickness: 20mm), weighing between 20-25 g, its color is white and fairly firm consistency. It is located in front of the rectum, behind the symphysis pubis perineal floor above and below the bladder. Surrounds the rear portion of the urethra, the tube that carries urine and semen to the outside and rich in prostate produces fluid that helps lysis of the ejaculation

Epidemiologic data

Prostate cancer is often the first tumor in the male population that suffers. In the U.S., ranks second in frequency as a cause of death in men. The American Cancer Society estimated that approximately 198,100 new cases of prostate cancer in this country in 2001 and about 31,500 men will die of this disease.

Venezuela in prostate cancer is the third leading cause of death in men and is more common in males of 70 years. The mortality rate is 2.1 per 1,000 men.

Most epidemiological studies suggest that the incidence of prostate cancer has increased over the years, but this may be partly due to improved detection and reporting of cases of prostate cancer. 92% of men diagnosed with prostate cancer survive at least 5 years, and 67% survive at least 10 years.

Risk Factors

Age: The chance of having prostate cancer increases rapidly after 50 years of age. Over 80% of all cases of prostate cancer are diagnosed in men older than 65 years.

Race: Prostate cancer is nearly twice as common among black men than among whites.

Nationality: The frequency of prostate cancer is high in North America and Europe, intermediate in South American countries and low in Eastern countries.

Diet: The results of most studies suggest that men who eat a lot of fat in their diet are more likely to develop prostate cancer. Recent research also suggests that a diet high in calcium and low in fructose (fruit sugar) increases risk of prostate cancer. The lycopene, found in particularly high levels in some fruits and vegetables (such as raw or cooked tomatoes, grapefruit and watermelon) also appear to reduce the risk of prostate cancer, as does selenium.

Hereditary Factors: Prostate cancer seems to be common in some families, suggesting an inherited or genetic factor. Having a father or brother with prostate cancer doubles the risk of a man developing the disease. The risk is even greater in men with several affected relatives, particularly if those relatives were young at the time of diagnosis.

Hormonal Factors: The active androgen which acts as an intermediary is prostate growth and male estradiol levels increase with age, those acting in synergy to induce growth.

Stages of prostate cancer

Clinical Manifestations

Symptoms of prostate cancer are:

• Obstructive symptoms: post-drip, effort, urinary stream with little strength or size.
• Irritative symptoms: frequency, urgency, tenesmus, suprapubic tension, dysuria.
• Sexual symptoms: decreased erectile function, ejaculation pain, discomfort in the erection, low satisfaction, bloody ejaculations.
• Hematuria: at the terminal (end of urination).
• General symptoms: fatigue, anorexia, cachexia, weight loss.

Prostate cancer remains a highly variable natural course and unpredictable in some men, the disease develops very slowly and their clinical condition is satisfactory for 10 years without treatment. In others, rapid metastatic spread disorder shows that culminates in early death. Today it is considered that if the man lived 100 years 90% will have prostate cancer.

Physical examination, the patient may present with lymphadenopathy, signs of uremia and congestive heart failure, or urinary retention with bladder distension. Most often, physical alterations are confined to the prostate. On rectal examination, the gland feels harder than normal or hyperplastic, and sometimes they have lost their normal limits. Up to 50% of the indurated areas located within the prostate are malignant, and the rest are due to calculations prostate with inflammation, infarction of the prostate or a change in postoperative patient who previously underwent partial prostatectomy for benign prostatic hyperplasia. If we discover an induration carcinoma suggests that it is necessary to establish whether their nature is focal or diffuse and appears to extend beyond the edge of the prostate.

Diagnosis

Medical science makes use of several methods for detecting the presence of prostate cancer.

Digital Rectal Exam: or DRE, is the most widely used and serves to assess the size, shape, and consistency of prostate, as well as the presence of nodules or indurated areas. This procedure is very fast and causes little discomfort to the patient.

Prostate Specific Antigen (PSA): Another common procedure, often used by digital rectal examination, is the PSA, the detection method is more modern, built to be used in the diagnosis of prostate cancer.

The PSA is a serine enzyme - protease belonging to a mily which was discovered in 1978. It is a prostate tissue-specific protein and is found in the seminal plasma, in serum and epithelial tissue of the prostate. The normal serum level is less than 4 ng / ml.

Although in most cancers is high, there are also abnormal in non-cancerous conditions of the prostate (prostatic manipulation significantly massage prostate, transurethral prostatectomy, cystoscopy, prostate biopsy, prostatitis and acute urinary retention, prostatic infarction and benign prostatic hyperplasia). This is due to a broken basement membrane, which is the natural barrier of containment which, under normal conditions, prevents the escape of PSA into the bloodstream. Serum PSA levels also vary with the patient's age and size of the prostate.

Several studies report that APE has an acceptable sensitivity but does not demonstrate a great specificity, thus they have the same variables to improve its capacity to detect and thus predict the number of biopsies for false positives.

The methods have been proposed are:

PSA velocity (APEV) is defined as the variation (increase) of serum PSA with time between two consecutive dosage and is said to predict that cancer, the observation period should be extended and increased APE should be more 1 ng / ml per year of observation. The APEV is very useful in long periods of observation.

PSA density (APED) is the quotient of dividing the serum PSA concentration by the volume of the prostate determined by transrectal ultrasound (APED = PSA / prostate volume). The principle of using APED is that produced 0.3 ng / ml per gram of normal or hyperplastic prostate tissue, therefore, the serum PSA level depends largely on the volume of the prostate. However, the APED is not recommended as the primary method for selecting patients for prostate biopsy because the published results are mixed.

Age-specific PSA: This concept is based on the serum PSA increased in relation to the age of the population. The age-specific PSA improves the positive predictive factor, but lost men diagnosed with the cancers that can be offered curative local therapy. Therefore, it is recommended the level of serum PSA of 4 ng / ml.

Forms of PSA, the serum PSA was found in three molecular forms: free PSA, PSA-conjugated alpha-1-antiquimotripsina and APE combined with alpha-2-macroglobulin. Of these, only the free PSA and complex PSA: alpha-1-antiquimotripsina can be quantified with currently available immunoassays for PSA, and these two forms represent the so-called total PSA in plasma or serum.

Prostate-specific antigen

Initial results suggest that the proportion of PSA forms complexes with alpha-1-antiquimotripsina is significantly higher in prostate cancer than in benign hyperplasia of the prostate in the latter, although the proportion of APE is Conjugated majority exists APE Free for cancer, so the percentage of free PSA is the best and most promising of all the proposed methods to improve the positive predictive and select men who need prostate biopsy.

Transrectal prostatic ultrasound: Another method for detecting prostate cancer is the technique of transrectal ultrasound prostate, which reflects sound waves to crash into the tissues of different densities of the prostate. The sound waves resulting from reflection are transformed in the case of prostate cancer in anechoic and hypoechoic images.

Puncture / biopsy of the prostate: The only way to determine whether a mass is suspected prostate cancer is to examine microscopically a sample of tissue taken from the area. This sample can be extracted by a needle placed directly into the prostate through the rectum or perineum (the space between the scrotum and anus). This procedure is called a puncture-needle aspiration (FNA) or needle biopsy. It can also be obtained through a biopsy.

In conclusion, the determination of PSA, digital rectal examination and transrectal prostate to take the respective biopsy is the definitive diagnosis of prostate cancer.

Imaging studies also help in diagnosis. These are:

1. The elimination urography for evaluating the urinary tract high
2. The retrograde urethrography showing an image of the wire stiffness posterior urethra
3. The Eco-abdomino pelvic organs to evaluate abdominal
4. The computed tomography (CT) abdominal staging to establish
5. The bone scan images to determine osteolytic and osteoblastic bone discomfort with

Microscopic examination in most of the tumors were adenocarcinomas with well-defined glandular patterns. Typically, the neoplastic acini and irregular forms that are distributed randomly in the stroma. The cytoplasm of tumor cells did not show distinguishing features and is usually pale or darker with eosinophilia. The nuclei are large vacuolated and contain one or more large nucleoli.

Metastatic spread

Prostate cancer can be localized in the prostate, locally advanced (disseminated disease, but not distant sites), or an extension may occur remotely (metastasis). When it does spread through:

Local infiltration into the tissues surrounding the prostate, is frequent involvement of seminal vesicles and the base of the bladder, causing obstruction.

Through the lymph nodes, to the regional lymph in the pelvis, and after the shutters perivesicales, hypogastric, and iliac. The spread in this way is common and often a precursor to bone metastases.

Through the blood, affecting mainly the bones especially the vertebrae, they can be osteolytic, but are more frequent osteoblastic and finding them in a man should always think about prostate cancer. In descending order of the bones most often affected are the lumbar spine, the proximal femur, pelvis, spine and dorsal ribs.

Have been observed, rarely, metastasis to liver and lung.

Treatment

Surgery. Radical prostatectomy by Walsh is the most effective way to cure prostate cancer confined. In this technique, removes the entire prostate and both seminal vesicles via high. The overall ten-year actuarial cure defined by undetectable serum PSA is 70% after radical prostatectomy, and increases to over 85% in men with the disease in clinical stages A1-B1. The major complications of radical prostatectomy are incontinence and impotence.

However, recent advances in surgical technique have minimized the risk of significant incontinence less than 5%, and allowed to retain sexual function in most men who do this technique.

The TURP is indicated for those tumors where art is needed to improve the quality of life.

Radiation. We use two main types of radiotherapy: external-ray radiation and brachytherapy or internal radiation therapy using interstitial radioactive seeds that are implanted surgically in the prostate. Although there is still no general agreement on this, it seems more appropriate radiotherapy in patients with limited disease who do not want to undergo radical prostatectomy or who are unfit for surgery because of age (over 70 years) and their health status. Radiotherapy is the treatment of choice in patients with clinical stage C disease that has spread beyond the edges of the prostate and therefore can not be cured with surgery.

Hormone therapy. Is the key to the treatment of patients with disease in different stages, aims to remove circulating androgens and thus cause the regression of primary and metastatic lesions. Hormonal ablation is achieved by medical or surgical castration.

Historically, to achieve the first, but this method has been abandoned almost entirely, by the appearance of cardiovascular complications and gynecomastia.

Medical castration is done at present with agonists of luteinizing hormone-releasing hormone (LHRH), which inhibits testosterone, either alone or in combination with antiandrogens, which block the action of androgen in the prostate itself. These agents have the same efficiency as current hormone (estrogen) or orchiectomy, and the addition of an antiandrogen added several months to survival. Recurrence after hormone therapy is due to the relentless proliferation of cells insensitive to the hormone, and new efforts to decrease serum testosterone produced little or no additional mitigation.

A happy old man with his wife after undergoing successful chemotherapy

Chemotherapy. It is used for patients whose prostate cancer has spread outside the prostate gland and who have failed hormone therapy. It is not expected to destroy all cancer cells, but can slow tumor growth and reduce pain. Chemotherapy is not recommended as a treatment for men with prostate cancer at early stages.