What is prostate cancer
For tumor prostate means an abnormal growth of cells in the prostate gland, and in particular with characteristics of malignancy; and the second cause of cancer mortality after lung malignancy, despite being more frequent of the latter.
There prostate it is a gland that produces its own secretion, the prostatic fluid, which is normally added to the seminal fluid during ejaculation. It is placed below the bladder, around the urethral canal into which it pours its own secretion, and is divided into a central area (about 25% of the volume), a small transitional area and a voluminous peripheral area (70% of the volume) . From the point of view histological, the gland consists of a supporting fibromuscular stroma within which the branched tubuloacinar glands that produce prostatic fluid are included, in a number ranging from 30 to 50; they pour their own secretion inside small ducts that flow into larger ducts, which end at the level of the prostatic sinuses, on both sides of the seminal colliculus inside the urethra.
Malignant prostate cancer originates from glandular tissue (unlike prostate adenoma in which there is instead a proliferation of stroma cells), and is therefore also called prostate adenocarcinoma. In particular, in 70% of cases it originates from the peripheral area, in 20% from the transition area and in 10% from the central area: this is important in terms of rectal exploration, which is one of the main diagnostic maneuvers, it is not possible to verify the presence of nodules - as long as these are small - when they are inside the central area; the maneuver alone is therefore not sufficient to exclude the diagnosis if the presence of nodules.
It is the most frequent type of cancer in men, with a prevalence rate that increases by 3-4% for each year from 50 years on, up to 80% over 85 years of age.
In Italy it is affected 1 in 8 men, and 1 in 30 dies from cancer.
Risk and protection factors
What are the causes of prostate cancer? In the genesis and growth of all tumors there is never a single cause (except in some cases), as the formation of tumor cells is due to various factors of different origin. Surely there is a certain percentage, variable from tumor to tumor, of genetic predisposition, which is the substrate on which environmental risk factors can act which can be physical (ionizing radiation), chemical (carcinogenic substances) or biological (particular infections). Some work activities (textile industry, polluting factories) and leisure activities (smoking, alcohol, coffee), as well as diet, have been associated with a number of different tumor types.
In the case of prostate cancer, the main risk factors for its development are:
- The advancement of age, both for the normal aging of cells, and for the greater possibility of exposure to other risk factors;
- Familiarity. The development of prostate cancer is more likely if you have relatives affected by the disease;
- L' ethnicity: prostate cancer is more common in African Americans and in the Scandinavian population, followed by Caucasians and finally by Asians;
- Radiation ionizing;
- Pollution atmospheric;
- Diet rich in fat and meat, and poor in fruit and vegetables;
- High levels of testosterone: this hormone is certainly not a direct cause of the tumor, but it favors its maintenance and progression.
- There is perhaps a correlation between the intervention of vasectomy and the development of prostate cancer, but it has not yet been proven.
Some food factors that have a protective effect are: soy (which contains phytoestrogens), the tomato (which contains lycopene), fruit (especially the pomegranate), green tea and vitamin E (in adequate quantities).
Prostate Cancer Symptoms
The high mortality of the malignant tumor of the prostate it comes from the fact that this causes only a lot of manifestations belatedly: due to the absence of initial symptoms, many people suffering from prostate cancer they don't know they are, and this allows the tumor to continue growing until it metastasizes.
When the cancer becomes symptomatic, the disorders it causes can be divided into three categories:
- Prostate cancer symptoms from infiltration local, due to invasion by the growing cells of the structures adjacent to the tumor mass:
- ache perineal (in the area between the anus and scrotum)
- hemospermia, or the presence of blood in the ejaculate
- hematuria, presence of blood in the urine, due to invasion of the prostatic urethra
- impotentia erigendi (impotence, or erectile dysfunction), ie the inability to achieve penile erection. This symptom is due to the destruction of the nerve fibers of the pudendal nerve, which are used to allow an erection.
- Prostate cancer symptoms from compression local, when the tumor mass grows a lot in size and compresses the contiguous structures:
- urination hesitation, i.e. lengthening the time to start urination
- mitto hypovalid (low urine flow) and / or interrupted
- drip terminal
- urinary infections due to chronic urinary retention
- Prostate cancer symptoms from metastasis, which are most frequently located in the bones, lymph nodes, lungs and liver:
- bone pain in case of bone metastases
- lymphedema for lymph node metastases
- dyspnea, cough for lung metastases
For the diagnosis of prostate cancer it is necessary to go through various stages, which lead first to the suspicion and then to the certainty of the pathology.
First of all, it is important to check for the presence of the risk factors listed above, and to associate them with any symptoms: this can already provide some suspicion of prostatic pathology.
Subsequently, it is useful to proceed with an investigation of rectal examination by the doctor, through which he can verify the presence of a possible nodule at the level of the prostate gland (unless this is still small and is in the central area). This investigation is very important from the point of view of prevention as, although it can sometimes be unpleasant, it allows for a quick check that can lead to the identification of the tumor: the earlier the diagnosis, the higher the person's life expectancy.
At the same time as prevention, a very important investigation is the dosage of PSA. This marker is a kallikrein class protein that is produced by cells of the prostate gland and serves to dissolve seminal clots that form in spermatic fluid. The PSA dosage gives the doctor an idea of any pathological processes that are occurring in the prostate: the PSA can be increased during a prostatitis, after a rectal examination or a long ride on a bicycle or motorbike (by compression of the prostate cells), and obviously also in prostatic hypertrophy (the so-called "enlarged prostate"), In benign prostatic hyperplasia (o prostate adenoma) is in the prostate cancer.
PSA levels normally have values between 0 and 4 ng / ml, and can increase in the pathological processes mentioned above up to values higher than 10 ng / ml. For values below 4 ng / ml there is a 5% probability of the presence of carcinoma; for values between 4 and 10 the percentage rises to 25%, up to 55% in the presence of values greater than 10 ng / ml. To improve the reliability of PSA values (when higher than 4 ng / ml), three other parameters may be required at the same time as its dosage:
- ratio between free PSA and total PSA: if it is lower than 15%, the probability that the tumor is present increases (but there is still no certainty).
- PSA density: is the ratio between the PSA value and the volume of the prostate (measured by transrectal or suprapubic ultrasound). It can be indicative of cancer when greater than 0.1.
- PSA velocity: indicates the amount of annual increase in PSA dosage; values greater than 0.75 ng / (ml * year) may indicate the presence of prostate cancer.
Further diagnostic investigations are: ultrasound suprapubic or, better, transrectal, which also allows to investigate the central area of the prostate; there bone scan and the CT scan to search for metastases.
The diagnosis of certainty is given exclusively by the biopsy, which is made only in the presence of PSA> 4 ng / ml, detection of a lump on rectal exploration and indicative ultrasound findings. The biopsy consists in the removal of a piece of tissue from the suspected nodule and its subsequent anatomo-pathological analysis.
The PSA not seems useful as a test of screening: in fact, an important Swedish study in 2014 highlighted the lack of advantages in measuring PSA in the absence of symptoms or clinical suspicion. Future studies may confirm or contradict this claim.
Grading and staging
Through the evaluation of the tissue sample taken through the biopsy, the Gleason Score. In the analysis of the two different areas most represented within the sample, the pathologist assigns each of them a score between 1 and 5 where 1 indicates the presence of well differentiated cells (therefore with little malignancy), while 5 indicates the presence of undifferentiated cells (high malignancy). The Gleason score is nothing more than the sum of the two values, and will therefore be between 2 and 10; this score determines the overall malignancy of the tumor tissue.
L'life expectation of subjects with prostate cancer is closely linked to PSA values, TNM staging (which assesses the size and presence of metastases to lymph nodes and other tissues) and to the Gleason grade. It is therefore necessary that all three of these parameters are evaluated in order to provide any estimate of the subject's survival.
In general, in the presence of early stage disease, the cure rate is very high, reaching almost 100% at 5 years; for advanced carcinomas, however, the survival at 5 years it is around 40%. There life expectancy it may drop to 20% if systemic metastases are present.
Exist care for the prostate cancer? Therapeutic interventions for prostate cancer depend mainly on four factors: tumor extension, its aggressiveness, the patient's life expectancy and the presence of concomitant pathologies.
The therapeutic possibilities are various, and can be both medical and surgical:
- “Wait and watch": In the case of very elderly patients with comorbidities, if they suffer from carcinoma with a low degree of malignancy, it is possible not to do any therapy, as they would shorten the patient's life expectancy more than the tumor itself would do (in in the elderly, tumors progress more slowly).
- Surveillance active: if there are no metastases and the grade is not advanced, it is possible to check the evolution of the tumor, without intervening, with dosages of PSA, magnetic resonance and biopsies every 3-4-6 months.
- Radical prostatectomy: also called prostatovesiculectomy radical, especially for localized tumors, this is the procedure of choice. This is an operation that allows the removal of the entire prostate gland, together with the seminal vesicles, through an open, laparoscopic or assisted by surgical robot approach. However, this treatment can have some unwelcome consequences, being burdened by a risk, albeit small, of going to cause urinary incontinence and impotence. Instead, TURP (transurethral resection of the prostate) is not used, reserved for patients with benign prostatic hypertrophy.
- Radiotherapy: it is a conventional therapy also used in the case of localized tumors, in subjects in which surgery is not possible. It is able to give almost the same results as surgery in terms of tumor destruction. It is possible to act from the outside with high energy radiation or to implant radioactive seeds in the prostate (brachytherapy).
- Hormone therapy: used in case of advanced tumors. As one of the main factors leading to the progression of prostatic neoplasm is testosterone, it is possible to deprive the tumor of this support through a sort of chemical “castration”, using central (GnRH at stable concentrations) or peripheral antiandrogenic drugs, typically administered with a monthly injection.
- Chemotherapy: is reserved for patients who do not respond to hormonal therapy, and only has effects of temporary relief of symptoms.
- Cryotherapy: used as an alternative to surgical therapy, it is a treatment with liquid nitrogen, with which the area of the prostate where is the tumor at -170 degrees centigrade.
Follow up and relapse
The follow up after tumor removal therapy is based on values of PSA, as this substance is produced exclusively by prostate cells. If there are PSA values higher than 0,2 ng / ml (after surgical therapy) or higher a 2,0 ng / ml (after radiotherapy), it is likely that there has been incomplete removal or destruction of the tumor prostate tissue and that a relapse, i.e. new neoplastic tissue that is growing, or that they are present metastasis which had not been previously identified.
After finding a high PSA value it is advisable to perform more investigations diagnostic (ultrasound, resonance, etc.) in order to make a picture of the new situation.
Tags: Surgery Oncology Prostate