Prostate Cancer: Causes, Symptoms, and Treatments

The prostate is a male organ responsible for the secretion of a fluid that favors the function of sperm. It is located at the outlet of the bladder and surrounds the urethra, the tube that allows urine to escape from the bladder.

Prostate cancer is the development of malignant cells within the body, leading to a progressive increase in size. This increase in size compresses the urethra, producing the characteristic clinical manifestations of this disease.

Prostate cancer is more common in the elderly and has a certain hereditary component, being more common in relatives of patients who have already had prostate cancer. It is one of the most common cancers in men.

Autopsy studies have shown that a large number of men who die from any other cause had prostate cancer without any symptoms. Therefore, given the slow growth of prostate cancers, many people with this cancer die of anything else without ever having symptoms.

What are the causes of prostate cancer?

The causes of prostate cancer are unknown. Apart from advanced age and a certain genetic component, no other risk factors for its development have been identified. Men who have inherited a mutation in the BRCA gene, a disorder closely related to breast cancer and ovarian cancer in women, have a higher risk of developing prostate cancer.

Symptoms of cancer in the prostate

The clinical manifestations of prostate cancer can be:

Difficulty when trying to urinate.
Increased frequency and urgency to urinate, generally emitting a small amount of urine.
Increase in the number of times you go to urinate at night, forcing the patient to get up several times.
Decreased force of the urine stream.
Other symptoms related to prostate growth can be erectile dysfunction (impotence), emission of blood with urine or when ejaculating, a higher frequency of urinary infections and the possibility of acute urine retention, that is, the absence of sudden and complete emission of urine that is accompanied by severe pain in the lower abdomen and inability to urinate. Urinary retention can be favored by the development of infections, the consumption of alcohol or the consumption of antihistamines or tranquilizers.

All these local symptoms can also appear in benign prostate diseases such as benign prostatic hyperplasia. They occur in advanced stages of the disease, although they are sometimes the first manifestation of cancer.

They consist of the appearance of bone metastases due to the extension of the tumor towards the bones. Bone metastases cause bone pain, generally in the lumbar region (in the area of the kidneys), due to involvement of the vertebrae.

How is prostate cancer diagnosed?

The initial diagnostic suspicion of prostate cancer is established by performing a digital rectal examination and determining the concentration of PSA (prostate specific antigen) in a blood test.

The biopsy is done transrectally, that is, inserting a needle into the anus and puncturing through the rectum. For this, the biopsy is guided by rectal ultrasound.

An ultrasound probe is inserted through the anus and several biopsies are obtained with a needle. About 6 biopsies are usually obtained so as not to leave any area of the prostate without evaluating.

Cancer is found by biopsy in about a quarter of people with a PSA greater than 4 ng / mL and an abnormal rectal exam. If PSA remains elevated over time and initial biopsies have been negative for cancer, repeated biopsies are sometimes recommended.

In case a prostate cancer is found in the biopsy, the pathologist must indicate its degree of aggressiveness according to the Gleason scale. A cancer with a score on this scale between 2 and 6 is considered low aggressiveness, a value of 7 is intermediate aggressiveness and a value greater than 8 is considered aggressive. The more aggressive the worse the prognosis.

How is the extent of the disease assessed?

Knowing the level of prostate cancer is important as it has implications for prognosis and treatment.

The most common classification is called TNM.

The T indicates the local extension of the tumor:

T1. The tumor is not palpable by rectal examination and has been diagnosed by the presence of an elevated PSA and by subsequent biopsies.
T2. The tumor is palpable on digital rectal examination and is located in the prostate, affecting only 1 of the 2 lobes of the prostate (a and b) or 2 (c).
T3. The tumor extends beyond the prostate and can invade the seminal vesicles.
T4. The tumor invades nearby structures beyond the seminal vesicles such as the bladder, rectum, local muscles, etc.

The N indicates the presence of nodes:

N0. There are no nodes.
N1. There are nodes.

The M indicates the presence of metastases:

M0. There are no metastases.
M1. There is distant extension of the tumor (metastasis).

In general, to assess the extension, prostate ultrasound is usually recommended and sometimes MRI and bone scan to see if there is metastasis.

Eight out of 10 prostate cancers are diagnosed with localized disease in the prostate (T1 and T2) and are associated with a 5-year 100% survival. Local extension (T3 and T4) without metastasis is also associated with 100% survival. The few patients who are diagnosed when they already have metastases have a 5-year survival of greater than 30%.

Cancer treatment

Treatment depends on the extent of the tumor and the life expectancy of the patient for reasons other than prostate cancer. Due to the fact that it is a disease that affects the elderly and that can progress slowly, in many cases, it may not be advisable to carry out aggressive treatments and the evolution should simply be monitored.

A localized tumor (stages I and II). When the tumor is located in the prostate, surgery can be performed to completely remove the prostate (radical prostatectomy), give radiation therapy, or simply do nothing and monitor. It depends in many cases on the discomfort that the patient has, their personal preferences and, as already indicated, their quality and life expectancy for other reasons.

The prostatectomy by surgery can be performed by open prostatectomy, opening the abdomen, or by robotic prostatectomy, through multiple incisions in the abdomen where cameras and surgical instruments are introduced. Both techniques produce the same cure rate and have the same risk of complications and recovery time. Prostatectomy can cause urinary incontinence (urine leakage), sexual impotence, or intestinal discomfort.
The radiation can be performed from outside the body (external radiotherapy) or placing radioactive implants in the prostate itself (internal radiation therapy or brachytherapy). In brachytherapy, the device that emits radiation can be low intensity, in which case it is placed inside the prostate and is left for life progressively losing intensity, or high intensity, in which case it is placed for 1 or 2 days while you are admitted to the hospital, and then it is removed. The most common adverse effects of radiation therapy are the need to urinate several times a day, pain in the bladder area, urinary retention, and pain and inflammation of the rectum area. Radiation therapy causes more long-term intestinal complications than surgery and can also cause problems of sexual impotence. Radiation therapy treatments are often associated with hormonal treatments that block the action of androgens (male sex hormones).
The strategy of doing nothing and watching is to have regular check-ups (every 3 to 6 months) that assess the growth of cancer. If the tumor increases in size, then treatment is decided. It can be used for small, very slow-growing cancers with low Gleason stages. It is an appropriate option for people of advanced age or with multiple diseases in which surgery or radiation therapy can have serious complications.

Locally advanced tumor (stage III). It is cancer that has spread beyond the prostate gland. Treatment usually consists of:

Radiation therapy (external or internal) associated with antiandrogen hormonal treatment.
Radical prostatectomy together with subsequent radiotherapy.

Tumor with metastases (stage IV). Treatments are not curative but can control cancer growth for long periods of time, reducing symptoms and improving quality of life.

Antiandrogenic hormone treatment (anti male sex hormones). It is usually the initially recommended treatment. This treatment is intended to reduce the production of male hormones or block their effects so that the tumor does not continue to grow. Some doctors recommend starting this treatment the moment metastases are discovered, and others only when the metastases produce symptoms.

There are advantages and disadvantages to each of these treatments, although the efficacy is similar. In general, this type of treatment produces a syndrome of lack of male sex hormones that manifests itself with fatigue, weakness and loss of muscle mass, hot flashes, impotence, depression, breast growth ( gynecomastia ), personality changes and loss of bone mass. Medicines can also be used to block the effect of androgens at the tumor level (flutamide, bicalutamide, etc.). These medicines have adverse effects similar to the previous ones, although less marked.

Abiraterone. It blocks the production of androgens by the prostate cancer itself and in other locations. It is usually used when the tumor becomes resistant to or associated with antiandrogenic hormonal treatment. It must be used in combination with prednisone.
Enzalutamide and apalutamide. They also block the action of male hormones.
Chemotherapy. It is usually the appropriate treatment when advanced cancer does not respond to hormonal treatment.In addition to the previous treatment, it is necessary to control the pain, especially if the bones are affected. In addition to the usual treatments for pain, there are specific treatments with radioisotopes (Radio-223) for the treatment of pain caused by bone metastases. They are used in cases of pain difficult to manage with medications.

Prostate cancer prevention

The development of prostate cancer cannot currently be prevented, but it can be detected early to establish the appropriate treatment.

Although there is much controversy, in men over 50 years of age, a rectal examination and PSA determination may be recommended from time to time. It is not indicated above 75 years because the detection of an anomaly from this age does not modify the prognosis.