GENERAL INFORMATION
What is prostate cancer?
It is the proliferation of malignant cells which starts in the prostate and passes unnoticed for years, finally progressing towards neighbouring organs and through the blood to other organs, especially the bones. It is unusual as it above all affects men of advanced age, is influenced by hormones and has a high cure rate. Furthermore, patients who already have metastasis in the bones can live for many years (more than 8) with hormonal treatment.
What causes it?
It is believed to be the accumulation of several causes such as family history, age, hormonal stimulation, a high-fat diet, possible venereal diseases, etc, which progressively lesion the genes of the prostate causing primary benign lesions which develop into cancer over the years.
Who has a propensity for prostate cancer?
It has been seen that there are racial factors, as American blacks have a greater propensity than American whites. Being above 70 years old is a risk factor, but a risk starts to exist after the age of 50. At 90 years old, 80% of men have prostate cancer, which does not mean that they are going to die of the disease. It can be said that these people die of cancer but not of prostate cancer, as life expectancy is high and gives time for people to die from other diseases associated with age. It is most common in north-eastern Europe and North America and very infrequent in the Far East.
Is there any way of preventing it?
It is considered that avoiding predisposing factors reduces the risk of suffering from prostate cancer. Men should avoid a high fat diet, the consumption of alcohol and other toxins, and venereal infections. In spite of all this however, age is a fundamental factor and if a man is of advanced age, he will always be at risk of prostate cancer. The best thing to prevent dying from this disease is timely diagnosis as an effective curative treatment exists.
I’ve heard that eunuchs do not suffer from this cancer; does castration prevent it?
It is true that eunuchs do not suffer from this type of cancer, however castration is only used as a treatment when the patient already has prostate cancer and not as a means of prevention. One of the main reasons is that this would have to be done when the man is still young so that there is a lack of hormones over many years. Some of the undesirable effects of this method are impotency and depression.
Can we prevent the disease with hormonal treatments?
By the same token the administration of anti-androgens is not used as a preventive measure as this would have the same effects as surgical castration. The drug finasteride is administered to prevent benign prostatic hypertrophy. Some studies suggest that it could also prevent cancer. More information will be available in the near future on its use in preventing cancer.
What can men do to avoid dying from prostate cancer?
The best thing to do is ensure early diagnosis, which consists of regular check-ups by a urologist or specialist doctor from the age of 50 (from the age of 40 if there is a family history of the disease or other very high risk factors). This consists of a rectal examination with a latex glove in which the doctor touches the surface of the prostate and takes blood samples to look for prostate-specific antigen (PSA). These procedures mean that there is a high likelihood of suspecting a tumour if there is one, or of ruling one out if not. They only serve to establish a suspected case as diagnosis is more complex; a lump in the prostate and a raised PSA level does not always mean that the patient has cancer.
Campaigns are being set up to analyse PSA levels in men aged above 50 years old “without symptoms” who are not at high risk and to find out whether patients with early detections live longer. This came about as a controversy exists about whether diagnosing the cancer in an earlier phase enables patients to live longer as often the decision after an early diagnosis can be to wait for its spontaneous development and not to treat the cancer. In conclusion, campaigns for early diagnosis have still not shown that the life expectancy of patients with a moderate risk of suffering from prostate cancer is increased.
In the hands of a specialist 80% of initial prostate cancer can be cured, but if the cancer is of low malignancy, the patient will live for many years without treatment. Nevertheless, with treatment he can live for the same amount of time but with a poorer quality of life due to the impotency and urinary incontinence caused by the treatment.
How does prostate cancer spread?
Initially it spreads to the rest of the prostate gland which is divided into several parts known as lobes. It sometimes starts in several lobes at once and is said to be multifocal. From here it invades neighbouring organs, above all the urinary bladder, and the pelvic lymph nodes. Later it can invade lymph nodes which are farther away such as those of the groin or those of the retroperitoneum next to the kidneys. Finally it can pass to the blood and create foci of metastases, most often to the bones and less frequently to the lungs, suprarenal glands, left supraclavicular lymph node (it arrives here via the lymphatic vessels), etc.
DIAGNOSIS
What are the symptoms of prostate cancer?
As is almost always the case with cancer, the disease has somewhat unspecific symptoms which can occur in other benign diseases such as benign prostatic hypertrophy.
This consists of pain on urinating, an increase in the frequency of urination, a reduction in the force of the flow of urine, still feeling uncomfortable after urinating, urinating a lot at night or residues of some drops of urine on finishing micturition. All of these symptoms are unspecific as mentioned previously.
More rarely it can be presented as a loss of blood with the urine. When prostate cancer has spread to the bones it can lead to intense and shifting pains in the bones, particularly at night when the patient is resting in bed.
How is the diagnosis made?
It is necessary to make a puncture or biopsy of the prostate or of any focus of metastasis if there is one. At the same time routine blood analyses should be made such as a haemogram, liver and kidney function tests, an analysis of salts dissolved in the blood and calcium, and specific tests for this cancer such as PSA (prostate-specific antigen). This information is not as specific as its name suggests and its level can be raised in other benign diseases, meaning that it should be interpreted by a specialist doctor.
Imaging tests are also used such as a transrectal ultrasound scan (through the rectum) to give doctors a better view of the existence and extension of the tumour, a chest X-ray, and bone tests, especially gammagrafía ósea, which is an X-ray of all the bones at once which is taken after injecting the patient with a radioactive contrast medium (using low levels of non-hazardous radiation) which accumulates for some hours in the bones and allows photos to be taken of them. If X-rays of bones are taken to see foci of metastases, these foci can be less dense and are at times more calcified than normal. On occasions it is appropriate to carry out other imaging tests such as CAT or Resonance (MRI), or abdominal (and occasionally pulmonary) ultrasound scan.
In the past pedal lymphography was performed in which a contrast medium was injected into a foot and then an X-ray taken of the contrast that appeared in the inguinal or retroperitoneal lymph nodes. CAT or MRI is preferred nowadays.
Why is the blood analysed?
This provides the doctor with information on the condition of important organs such as the kidney or liver and on whether metastasis is suspected in these organs or in the bones due to finding elevated levels of calcium or alkaline phosphatase. The PSA serves to monitor how the treatment is progressing and to reveal recurrences of the tumour if it has gone back to normal after treatment. Prostatic acid phosphatase is used less as it has the same function as PSA but is somewhat less sensitive and more expensive. The main thing is that it does not provide more information about the PSA.
The PSA also serves for early diagnosis in people without symptoms, as it is an indicator that prostate cancer might be present. Beware: a high PSA does not always indicate cancer. It may be raised due to benign diseases or alterations.
The PSA should be performed from the age of 50 and never after 80 in people without symptoms, as it is not clear whether it serves to enable people to live longer. Therefore if life expectancy is less than 10 years due to age or other diseases this means that the person will die from other diseases but not from prostate cancer.
Is it better to use an ultrasensitive PSA assay?
Analysis techniques are continually being improved. The ultrasensitive PSA assay detects the slightest changes and is theoretically better than the standard PSA assay. The latter is still useful and it is important not to confuse the measuring units of different PSA assays as they are not comparable. The reference values should be consulted with the laboratory. Extrapolation tables of different types of PSA assay are available.
Should the PSA be zero after complete prostatectomy?
It is not always zero, as this depends on whether the technique can detect residues of PSA. This is because remnants of the prostate always remain after the operation, especially the part that surrounds the urethra. This can never be removed without removing the urethra. These remains of the prostate mean that the PSA will not be zero, but reference values are available to help decide whether the residue is acceptable or higher than acceptable, and whether it is suspected that the tumour persists.
What role does a biopsy play in prostate cancer?
A biopsy is essential in order to make a microscopic study of the cells. Furthermore, it serves to classify the prognosis and the treatment to be followed according to the Gleason scale.
It can be rated as Gleason 2 to 10, depending on whether the cells seem almost normal, Gleason 2, or Gleason 10 if they seem very aggressive and malignant. When there are symptoms the most common situation is that cancer with a Gleason score of 7 or of 8 is diagnosed.
If the PSA and the Gleason score are low there is the option of not offering treatment and waiting to see if these figures increase or not. If the Gleason score is 7 or less it is usually treated with external surgery and radiotherapy or with radioactive seed implants within the prostate. If the figures are high, which indicates that the disease probably cannot be cured, patients can opt to do nothing or try to curb the cancer with radiotherapy and hormone treatment.
How do we classify how far the prostate cancer has spread?
There are several different ways to stage tumours which use numbers or letters, from low to high depending on whether on how far the disease has spread. The most complex is the TNM classification that assesses tumour, lymph nodes (lymph nodes) and metastases. This staging system can also be summed up more simply: stages 1 (or A), when it is located in the prostate it does not give symptoms; stage II (or B) when the tumour can be felt by rectal examination and the PSA is raised but without evidence that it has spread beyond the prostate; stage III (or C) when the tumour has spread to neighbouring organs; stage IV (or D), when the cancerous cells have spread to the regional lymph nodes or through the blood to distant organs.
How is it treated in localised cases?
Most men prefer resection by surgery to avoid later spread; it takes 3 or more weeks to recover from this procedure.
Radiotherapy on the prostate is used in men who are too old to tolerate surgery. If radiotherapy fails, there is still the option of operating. A new technology called three-dimensional radiotherapy is being introduced which directs the radiation more effectively against the tumour achieving better cure results with less toxicity.
The implanting of radioactive seeds (known as brachytherapy) in the prostate is an out-patient treatment which in expert hands offers greater convenience and high cure rates. It consists of introducing radioactive seeds, somewhat like the tip of a pencil, through the rectum into the prostate guided by ultrasound.
Radioactivity is eliminated through these seeds within the prostate and cancerous cells are thereby removed. One side effect is short-term urinary problems. This is a promising treatment for the immediate future.
TREATMENT
What are the disadvantages of the treatment?
The biggest disadvantage is mainly impotency which affects 60% of patients due to damage to the pudendum nerve which is responsible for erection, and urinary incontinence as the nerves of the urethra are affected in 8% of cases. These figures are similar with both surgery and radiotherapy.
If the pudendum nerve is not totally damaged then taking Viagra can work, but if it is totally damaged this will not work. In this case there are several types of inflatable manual pumping devices which can bring about erections artificially. All of these methods have their problems, but men have to choose between being impotent and being alive or not being impotent and dying.
When is hormonal treatment indicated?
It is indicated to curb the progression of the cancer when there is distant metastasis. It is also called chemical castration as it reduces and stops the secretion of testosterone and the cancer is therefore curbed. It also causes side effects such as impotency and feminisation of the distribution of fat and muscles in the body.
What types of hormone treatment are there?
There are basically two types: androgen blockers (which are male hormones) and administering oestrogens (which are female hormones).
Androgen blocking is firstly achieved by administering an anti-androgen hormone which blocks the effect of the natural androgens in the receptors of the cells where they act. The source of androgens is suppressed by orchiectomy or surgical castration of the testicles, inserting a testicular prosthesis made of silicone. Another method is chemical orchiectomy which consists of suppressing the secretion of testosterone using hormones which block this action in the testicles. This is achieved with hormones similar to those secreted by the hypophysis but which do not have the action of stimulating the testicles but instead of inhibiting them.
Oestrogens are used less these days than androgen blockers as they have more side effects, such as feminisation and impotency.
How do we know if the treatment works?
It is relatively easy in prostate cancer, as the symptoms disappear quickly if they exist and the PSA in the blood falls to normal levels. Furthermore, several different types of X-rays and ultrasound scans can be made to see images of the development of the tumour.
PROGNOSIS
What is the prognosis of prostate cancer?
This depends on several factors, above all the stage: in stage A 70-80% remain disease-free 5 years after diagnosis which is the same as saying that 70-80% are cured; in stage B, 50-80%; from 15 to 70% in stage C and 6 to 30% in stage D with metastasis. In the latter case it is more risky to say that they are cured as recurrences are common beyond 5 years.
Other factors which bring about a poorer prognosis are tumours which do not respond to hormones, those which have invaded the lymph nodes of the pelvis, those which have invaded the seminal vesicles, those in which parts of the tumour remains in the margins of resection by surgery and those which have a Gleason score higher than 7.
MONITORING
Which controls should we make and how often?
Controls should be made at the discretion of the specialist doctor. In general, every 3 or 4 months for 3 years, and every 6 months for two years more. Afterwards, once a year, or every 3 months if there had been metastases even though they have disappeared.
The controls consist of a physical examination, blood analysis for PSA and other factors such as phosphatase alkaline or calcium in the blood serum, and on certain occasions, radiological studies.