Prostate cancer (prostate carcinoma, prostate tumor)

Prostate cancer (PCA) is a malignant tumor of the male prostate gland. The prostate is about the size and shape of a chestnut. It is located directly under the bladder and surrounds the upper part of the urethra in a ring. The main function of the prostate is to produce a secretion that is added to the seminal fluid during ejaculation (ejaculation).

As prostate cancer progresses, the urethra can become constricted, causing bladder emptying problems. In most cases, however, problems with urination are due to other causes, such as benign prostatic hyperplasia (enlargement of the prostate) caused by an adenoma (benign tumour). In addition, prostatitis or an infection of the urinary tract can cause similar symptoms.

Prostate cancer is the most common cancer in men in Germany. According to estimates, about 60,000 men in Germany are newly diagnosed with prostate cancer every year. The average age of onset is around 70 years. Prostate cancer cases before the age of 50 are very rare.

Since the prognosis is much better the earlier the prostate cancer is diagnosed and treated, men over the age of 45 are recommended to have an annual check-up with a urologist. However, the cancer is often diagnosed late because prostate cancer does not cause symptoms until it is advanced and few men complete the recommended cancer screening. In one in three cases of prostate cancer, the cancer is diagnosed so late that there is little or no chance of a cure.

The exact cause for the development of prostate cancer is not known. However, there are some factors that are suspected to promote the development of prostate cancer:

• Age: Age is the greatest risk factor for developing prostate cancer. Over 80 percent of all prostate cancer patients are older than 60 at the time of diagnosis.
• Genetic disposition (predisposition): Genetic factors also play a role in the development of cancer. The risk that first-degree relatives of prostate cancer patients will also develop the cancer is at least twice that of the average population. If two or more close relatives have prostate cancer, the risk increases many times over.
• Hormones: Hormones have a major influence on the development of prostate cancer, but their exact role is not yet fully understood. It is certain that the male sex hormone testosterone influences the development of the cancer by stimulating the growth of the cancer cells. Testosterone is mainly produced in the testicles and is necessary for prostate function. Without the influence of testosterone, prostate cancer cannot develop.
• Ethnic factors: The risk of prostate cancer varies greatly between different ethnic groups. For example, prostate tumors occur less frequently in the white population of the United States than in the population of color. Globally, men from Scandinavia are most likely to suffer from prostate cancer, while Asians are least likely.
• Dietary habits: Diets high in fat and calories and low in fiber are thought to increase the likelihood of developing prostate cancer. Since prostate cancer is much less common among Asians and vegetarians, it is believed that frequent consumption of vegetables, grains and soy products has a preventive effect.
• Occupational risk factors: It is very likely that exposure to radiation and heavy metals as well as vitamin D deficiency also increase the risk of prostate cancer.

Since prostate cancer mostly develops in the outer layer of the prostate, it does not cause any symptoms in the early stage of development. It is only when the cancer has progressed to the point where the urethra is constricted that the following symptoms may occur:

• Pollakiuria: frequent urination with small amounts of urine - the total amount of urine is not increased.
• Dysuria: difficult, deliberate emptying of the bladder
• Alguria: pain when urinating
• Erectile dysfunction
• Strong urge to urinate
• In rare cases, blood in the seminal fluid or urine

Only very rarely does a prostate tumour develop in the inner zone of the prostate gland, causing the urethra to become narrowed at a very early stage of the disease.

If metastases (daughter tumours) form, the lymph nodes of the pelvis are usually the first to be affected. The cancer can then spread further into the body - preferably into the bones of the pelvis and lumbar spine. The destruction of the bones can cause very severe pain. In addition, due to reduced bone stability, even minor injuries can lead to bone fractures. Furthermore, metastases may form in the liver or lung tissue.

Lymph node involvement in the groin and pelvic area can lead to the development of edema (fluid retention) in the scrotum and legs. In addition, in many cases, general symptoms of cancer occur, such as night sweats, fever, fatigue, unwanted weight loss, and decreased performance.

Benign enlargement of the prostate (benign prostatic hyperplasia) develops in the inner layer of the prostate. Since the urethra is narrowed very quickly in this case, this disease, in contrast to prostate carcinoma, already causes bladder emptying disorders in the early stages of development.

Early detection

Since the prognosis of prostate cancer is significantly better the earlier the cancer is diagnosed and treated, men should have regular cancer check-ups with their general practitioner or preferably with a urologist. Annual cancer screening is recommended for all men over the age of 45. Men with blood relatives who have prostate cancer should be screened earlier.

Palpation

The rectal palpation of the prostate (called palpation) serves as the first examination to detect prostate cancer. This involves palpating the prostate through the rectum with a finger, which allows the doctor to detect any enlargement of the prostate as well as nodular indurations in early stages of cancer. In many cases, however, the prostate cancer has already penetrated the capsule of the prostate, so it is no longer nodularly encapsulated. Prostate tumors that lie to the side or toward the abdominal wall cannot be palpated. Rectal examination may suggest a suspicion of prostate cancer, but a definite diagnosis is not possible.

PSA test

Prostate-specific antigen (PSA) is a protein produced in the prostate gland. It is not a specific tumour marker, as the PSA level can generally be elevated in any disease of the prostate. In addition, the level can rise when the prostate is massaged - for example, during rectal palpation, cycling or sex. The PSA level can then be elevated for up to 24 hours.

In contrast to Germany, the PSA test is part of the urological screening in Austria. The value of the prostate-specific antigen in the blood is determined. However, the test does not guarantee an exact diagnosis, as the PSA test can be negative despite prostate carcinoma or it can be positive due to another prostate disease.

Biopsy (tissue removal) and ultrasound examination

A reliable diagnosis of prostate cancer can only be made by means of a biopsy. During a biopsy, several tissue samples are taken from the prostate using a thin needle. The biopsy is performed under ultrasound guidance via the rectum (transrectal ultrasound sonography). The tissue samples are then examined in the laboratory under a microscope for the presence of cancer cells. In addition, the aggressiveness of the prostate tumor can be determined, which makes it easier to plan the subsequent therapy.

The biopsy is a safe examination procedure in which there is no risk of the tumour cells spreading. Tissue removal can be performed under local anaesthesia.

Checking the spread of the tumour

After a successful diagnosis, further examinations are carried out so that, for example, existing metastases (daughter tumours) can be detected:

• With the help of an ultrasound examination , it can be shown whether the tumor is obstructing the outflow of urine from the kidneys.
• An excretory urography (X-ray examination of the urinary tract) shows whether parts of the urethra, bladder or ureter are affected by the cancer. However, this examination procedure is rarely performed nowadays, for example in the case of an abnormal ultrasound finding.
• A chest X-ray (X-ray of the chest) can detect prostate cancer metastases in the lungs.
• A skeletal scintigraphy can be used to determine whether the cancer has already spread to the bones.
• A magnetic resonance imaging(MRI) or computed tomography(CT) scan is performed to detect other metastases. In addition, the results of these imaging procedures help determine whether surgery is appropriate.

Additional tests

Because not all parts of the prostate are reached when tissue is removed with a biopsy needle, in some cases the findings may be negative even though prostate cancer is present. If it is suspected that the patient nevertheless has prostate cancer, the biopsy may have to be repeated.

In order to circumvent this problem, completely new diagnostic methods are currently being developed. For example, protein analysis can be used to detect altered compositions of certain proteins in the urine, which may indicate prostate cancer. However, this is not yet an established routine procedure.

The type of treatment for prostate cancer depends largely on how far the cancer has progressed. In addition, the growth rate of the tumor as well as the general condition, age and surgical risk of the patient play a major role. There are numerous different treatment options available, which may also be used in combination with each other. It is therefore advisable to get a second opinion from another doctor before starting therapy.

Basically, the following treatment approaches are available:

• Surgical intervention
• Chemotherapy
• Hormone therapy
• Radiotherapy

Stages of prostate cancer

The treatment options and prospects for cure vary greatly depending on the stage of prostate cancer:

Limited prostate cancer

In this stage of prostate cancer, the tumor is still located exclusively in the prostate tissue. The therapy with the best chances of cure is a complete surgical removal of the prostate. If the tumour is still small, radiotherapy can be performed as an alternative instead of surgery.

For patients over the age of 75, or for those with small, barely aggressive tumors, the option of no treatment at first and watching how quickly the cancer progresses should be considered. Otherwise, the cancer therapy could cause far greater discomfort than the cancer itself.

Advanced prostate cancer

At this stage, the prostate tumor has already broken through the capsule of the prostate and is infiltrating the surrounding tissue. Since in many cases the cancerous tissue can no longer be completely removed by surgery, a cure for the prostate cancer is only possible to a limited extent.

As an additional treatment after surgery, an attempt can be made to kill any remaining tumour cells with the help of radiotherapy. It is also possible to inhibit the growth of the remaining cancer cells by withdrawing the growth-promoting hormone testosterone from the cells.

Metastases

If the prostate cancer has metastasized to other organs, such as the lungs or bones, it is usually no longer possible to cure the patient. A so-called palliative therapy is carried out, in which the treatment goal is to improve the cancer patient's quality of life. The further growth of the prostate tumour is inhibited by radical hormone withdrawal. In addition, an attempt is made to destroy the cells of the metastases by means of cytostatic drugs.

Therapy options at a glance

Active monitoring

If the prostate tumour is small and growing very slowly, the therapy can be postponed if necessary. This option should be considered especially in older patients over 75 years of age or in patients with poor health. Otherwise, the cancer therapy could cause far greater discomfort than the cancer itself. The further development of the prostate carcinoma is regularly examined and closely monitored.

Surgery

Radical prostatectomy (complete removal of the prostate) is the recommended procedure if the spread of the tumour is limited to the prostate gland and the surrounding tissue has not been infiltrated. At this stage of cancer, surgery offers the highest chance of cure. In addition to the prostate gland, the vesicular glands below the prostate gland and, in some cases, nearby lymph nodes are surgically removed.

If the cancer has already affected the surrounding tissue, the operation will at least relieve the symptoms. In addition to the prostate and the vesicular glands, all nearby lymph nodes must be removed.

In the conventional surgical procedure, the prostate is removed through an abdominal incision approximately 12 centimeters long above the pubic hairline. The minimally invasive laparoscopic procedure is an alternative method in which the surgical device is introduced into the abdominal cavity through five approximately 1.5-centimeter-long incisions. A complete opening of the abdominal wall is not necessary - the operation is performed with the help of a video camera inserted into the abdominal cavity. According to studies, however, the laparoscopic procedure is not necessarily gentler for the patient. Wound pain, recovery time and late effects such as impaired continence (ability to hold back urine) and erectile function are not always less than with conventional surgical procedures. The reason for this is that postoperative complaints depend less on the access route than on the individual circumstances of the operation and the skills of the surgeon.

A frequent late consequence of surgical removal of the prostate is loss of potency. Since certain nerves that are important for erection run directly along the prostate capsule, there is a great risk that these nerves will be damaged during the operation. Despite nerve-sparing surgical procedures, about 80 percent of men suffer from erection problems after the procedure. Stress incontinence occurs in about 3 to 5 percent of cases. In this case, coughing, sneezing or laughing can lead to an involuntary leakage of urine.

Radiation therapy

Radiation therapy can be given to a prostate tumor from the outside (percutaneous radiation therapy) or directly from the inside (radionuclide implantation, brachytherapy):

• Radiation therapy from the outside: Usually, five radiation sessions are given per week over a period of about eight weeks. A single radiation session lasts about 15 minutes.
• Radiation therapy from the inside: In a one-time procedure, radioactive grains about the size of grains of rice are placed inside the prostate. These radioactive particles continuously emit radiation a few millimeters deep into the surrounding prostate tissue over a period of about one year. Subsequent removal of the grains is not necessary.

Just like surgery, internal or external radiation therapy can also cause erectile dysfunction. This is because the radioactive radiation can also damage tissue that is necessary for the erection. About 50 percent of those affected suffer from erection problems after radiation therapy. The incidence of late effects of treatment, such as impaired potency or erection, is similar between nerve-sparing surgery and radiation therapy - differences are mainly the result of individual circumstances and the skills of the treating physician.

The radioactive radiation can also damage the intestines and urethra, which is why some patients experience problems with urination or digestion (for example diarrhoea).

Cryotherapy

Cryotherapy involves freezing the prostate tissue over the intestine, which then causes it to die. However, current evidence suggests that cryotherapy is less effective than other established treatments, so it is not an equivalent alternative in prostate cancer treatment.

Hormone deprivation

In many prostate tumors, the male sex hormone testosterone promotes the growth as well as the spread of the cancer. In about 80 percent of cases, inhibiting testosterone production can slow tumor growth and relieve the pain caused by the tumor. However, the extent to which prostate cancers respond to hormone withdrawal varies from patient to patient. In addition, the therapy loses effectiveness over time and the cancer can then grow independently of testosterone, making treatment more difficult thereafter.

Complete drug inhibition of testosterone has the same effects on the body as castration. The patient suffers from impotence, a decrease in libido (sex drive), hot flashes, weight gain, breast enlargement, and an increased loss of bone and muscle mass, leading to an increase in the risk of osteoporosis. Bone densitometry should therefore be carried out regularly as part of hormone withdrawal therapy and osteoporosis therapy may need to be initiated.

Hormone therapy

LHRH analogues and GnRH analogues can be used to lower testosterone levels. The effect is based on the fact that the active substances correspond to the body's own hormones, which have the effect of reducing testosterone production.

Antiandrogens , on the other hand, shield the prostate carcinoma from the hormone testosterone without affecting the production of the hormone. The drugs cause significantly fewer side effects because they do not lower the level of testosterone in the blood. However, antiandrogens are less effective than testosterone blockers.

Oestrogens (female sex hormones) can lower testosterone levels in the blood within seven days. However, they cause much more severe side effects in men than testosterone blockers. In addition, they should not be used in patients with cardiovascular disease.

Removal of the testicles

Because most testosterone production occurs in the testes, removing them can provide rapid relief from pain in late-stage prostate cancer by quickly lowering testosterone levels. Because removal of the testicles cannot be reversed and it is therefore a psychologically very stressful procedure for the patient, this procedure is now rarely performed for prostate tumors.

Chemotherapy

If the prostate cancer does not respond or no longer responds to testosterone withdrawal, chemotherapy is given to kill the cancer cells. However, cytostatics (cancer drugs) are primarily used to damage fast-growing tumor cells. Because a prostate tumour sometimes grows very slowly, chemotherapy for prostate cancer is difficult. A life-prolonging effect of cytostatic therapy has only been proven for fast-growing forms of prostate cancer. Since cytostatic drugs kill not only cancer cells but all rapidly dividing cells in the body (for example intestinal cells or hair root cells), chemotherapy causes severe side effects.

Palliative therapy

In many cases of an advanced, metastatic prostate tumour, those affected suffer severe pain. Since a cure can usually no longer be achieved, effective pain control is an important therapeutic goal.

Late-stage prostate cancer often leads to the formation of metastases in bone tissue, which can cause severe pain and bone fractures. The risk of bone fractures can be reduced by radiation therapy. In addition, certain drugs such as bisphosphonates can be administered, which inhibit the breakdown of bone substance.

Own measures

Since there is only a chance of a cure if prostate cancer is diagnosed early, annual cancer screening is very important for men from the age of 45. If there have been cases of prostate cancer in the family, screening examinations should be carried out earlier.

The speed at which the prostate tumour grows can vary greatly from person to person. In some cases, the cancer grows very slowly over a period of years, so that treatment may not be necessary. However, there are also forms of prostate cancer in which the cancer grows quickly and aggressively and can lead to death in a relatively short time. The exact reasons why some prostate tumours grow quickly or slowly are not known.

At the time of diagnosis, the course of the disease cannot be accurately assessed in many cases, making it difficult to decide what treatment should be given. Therefore, prostate cancer should be monitored and treated regularly by an experienced urologist.

The prognosis of prostate cancer depends largely on the stage at which the tumor is diagnosed. In general, however, the prognosis is quite favorable. If the prostate cancer spreads to the surrounding tissue and especially if the tumor metastasizes, the chances of cure decrease rapidly. The 5-year survival rate for prostate cancer is about 87 percent.

A healthy lifestyle can reduce the risk of prostate cancer. A normal body weight, a healthy and varied diet and regular physical activity are important. Alcohol should only be consumed in moderation. The following points should be observed:

• Normal body weight: with the help of a healthy, moderate diet and sufficient physical activity, a healthy body weight can be maintained or achieved. An effective and healthy way to reduce the intake of calories is to consume less sweets, sugar, fat and alcohol. All these foods are very high in calories and offer little essential nutrients to the body such as vitamins, fiber or minerals.
• Regular exercise: Physical activity can reduce the risk of disease. A half-hour to one-hour light workout at least five days a week will ensure adequate fitness.
• Healthy diet: Fruit and vegetables should be eaten daily if possible, but meat products (especially red meat) should only be consumed in moderation.
• Moderate alcohol consumption: It is recommended that men consume no more than two alcoholic drinks per day. One drink corresponds, for example, to a small beer, a shot glass of schnapps or an eighth of wine.
• Early detection: The earlier prostate cancer is diagnosed and treated, the better the chances of cure. Men should therefore have an annual cancer check-up from the age of 45. If there have already been cases of prostate cancer in the family, screening should be started earlier.