Prostate cancer is the most common malignancy in males (except for skin cancers) and the second for causing more deaths, being second only to lung cancer.
Despite the high mortality, most prostate cancers tend to have slow growth, being restricted to the prostate years without causing metastasis.
The prostate is a gland the size of a walnut (3cm in diameter) with approximately 20 grams of weight and present only in males. It is located at the base of the bladder and surrounds the initial part of the urethra, the tube that carries urine from the bladder to the penis.
The prostate is part of the male reproductive system and is responsible for secretion of a fluid alkaline (high pH) which protects the sperm from the acidic environment of the vagina and increases their mobility, facilitating the arrival of the same egg.
How does close relationship with the urethra cause changes in the size of the prostate compressing it and making it difficult to drain the urine, leading to symptoms of prostatism, will be explained further.
As the prostate leans against the rectum, it can be palpated by digital rectal examination, one of the simplest methods of evaluation of the gland. An enlarged or irregular prostate size due to the presence of a tumor can be easily identified by this method. We'll talk in more detail about the digital rectal examination in the diagnosis.
The prostate can grow and cause symptoms for three reasons:
As mentioned earlier in this text, prostate cancer is the most common cancer in males. It is a tumor that is usually indolent, slowly growing and may remain asymptomatic for several years.
We do not know that prostate cancer arises and there are few risk factors, the main thing is the age, this cancer is rare in patients younger than 40 years and extremely common after 80 years. As humans began to live longer, the diseases of the prostate begin to become increasingly frequent.
Risk factors
Because prostate cancer tends to have slow growth, remaining asymptomatic for many years, many older people have the disease and do not know about it. In fact, it is estimated that between 50% and 80% of men above 80 years have prostate cancer at some stage of its development.
Besides age, other risk factors have also been identified:
Afrodescendant (in this group, prostate cancer is more common and tends to be more aggressive)
Symptoms of prostate cancer usually occur due to obstruction of the urethra by the tumor. However, because the disease tends to progress slowly, this obstruction usually becomes apparent only in advanced stages of cancer as well.
Instead of benign prostatic hyperplasia which is symmetrical and grows in the prostate uniform, the prostate tumor is located and has irregular growth. Therefore, depending on the area where the cancer arises, there may be no compression of the urethra and, therefore, symptoms of an enlarged prostate.
In the illustration we show two examples of prostate cancer: the left, which grew up next to the urethra causing its compression and to the right the one that comes out of the urethra and causes urinary symptoms only when being very large.
When the tumor grows into the urethra and causes obstruction, the most common symptoms are:
Difficulty in urination
Jet weak urine
Pain when urinating
The need of frequent urination, since, with the obstruction of the passage of urine, the bladder is constantly filled, achieving only small volumes of empty time
Here it is noteworthy that, for the reasons explained in the previous paragraphs, these urinary symptoms are more common in benign prostatic hyperplasia than in prostate cancer. Most elderly patients with urinary complaints have actually prostatic hyperplasia. Since both diseases are very common in the elderly people, the patient may even have hyperplasia and cancer together, but the symptoms are usually caused by the first.
Currently the majority of prostate cancers are detected at early stages, before they cause symptoms, through the PSA, prostate ultrasound and digital rectal examination.
Hematuria and hematospermia (blood in urine and semen respectively) may occur in prostate cancer, but are not common symptoms. In these cases you must also think of kidney stones, urinary tract infection or bladder cancer.
Erectile dysfunction can be a symptom of prostate cancer, but is uncommon. The vast majority of cases of erection difficulties in the elderly are not caused by prostate cancer.
Some patients, who are not tested for disease screening, can only find out when the prostate tumor metastases begin to cause symptoms. If the tumor arises away from the urethra, it will cause metastases before they cause urinary symptoms. In this case the most common symptoms are pain and fractures due to bone metastases.
To avoid situations like these, international urological societies recommend screening for prostate cancer for all men over 45 years old.
There is a table of points called SCORE INTERNATIONAL prostatic symptoms. There are seven questions and each one receives a score from 0 to 5.
How many times was the situation of not emptying your bladder completely?
How often do you have to urinate again less than two hours after urinating?
How often it was noted that, during urination, it stopped and started again several times?
How often it was remarked that it was hard to hold urine?
How often have you observed that the urinary stream was weak?
How often did you have to push to begin urination?
How often, on average, did you have to get up at night to urinate?
Rectal examination
0 = No
1 = less than a fifth of the time
2 = Less than half of the time
3 = half of the time
4 = More than half of the time
5 = Almost always
Mild: 0-7;
Moderate: 8-19;
Severe: 20 or more
The above score evaluates the severity of prostatic symptoms, but does not differentiate between BPH, prostatitis and cancer. The differential diagnosis involves a digital rectal examination, the measurement of PSA, transrectal ultrasound and prostate biopsy.
Rectal examination can detect those tumors that grow toward the rectum. However, up to 35% of prostate cancers at an early stage are not detected by touch. The next illustration shows an example of tumor that is not detectable by digital rectal examination.
The PSA is a marker of prostate disease, collected by blood tests, which rises in BPH, and especially in prostate cancer.
PSA less than 2.5 = Low risk of cancer
PSA between 2.5 and 10 = Intermediate risk of cancer
PSA greater than 10 = high risk of cancer
PSA greater than 20 = very high risk of cancer and high chance of metastatic disease
When the PSA and digital rectal examination raise suspicion of neoplasia, a prostate biopsy should be performed.
Once the diagnosis of cancer is made, you should evaluate the degree of invasion (tumor stage) and aggressiveness (Gleason score).
The Gleason score is obtained after analysis of prostate biopsy, going 1-10, the higher is the value, the more aggressive cancer are the cells.
Patients with signs of local tumor invasion, Gleason 6 or PSA greater than very high, there is a high risk of disseminated disease and bone scintigraphy must be performed to identify possible bone metastases.
After this initial assessment of prostate cancer is divided into four groups:
Group I: early disease with microscopic tumor and confined to the prostate (PSA less than 10 and Gleason less than 6)
Group II: tumor confined to the prostate, but now large enough to be felt on rectal exam (PSA less than 20 or Gleason = 7)
Group III: tumor has invaded the organs around the prostate
Prostate cancers at an early stage are potentially curable by surgery and radiotherapy. Cancers of low aggressiveness take between ten to twenty years to invade other tissues. When they occur in patients with advanced age they cannot be processed, since the risks and consequences of treatment are not justified on one with a life expectancy less than that required for tumor progression.
Complications of treatment include impotence, incontinence and decreased libido. Advanced tumors without metastases are treated with radiotherapy. Tumors with metastases are treated with drugs that are hormonal blockade (inhibition of testosterone) and generally have a poor prognosis.
For more detailed information for the treatment of prostate cancer read about medicine Casodex.
