What is prostate cancer?
Prostate cancer is a malignant tumor that originates in the prostate gland, a small gland that lies below the bladder and surrounds the urethra. The prostate has an important function in the male reproductive system by producing fluid that is part of the semen.
Most prostate cancers grow slowly and can be present in the body for many years without causing symptoms. In some cases, the tumor grows faster and can spread (metastasize), mainly to the bones and lymph nodes.
Every year, approximately 10,000–12,000 men in Sweden are diagnosed with the disease. The risk increases clearly with age and prostate cancer is uncommon before the age of 50. Most people who are diagnosed are over 65 years old and the average age at diagnosis is around 70 years. This is due both to the fact that the disease becomes more common with age and that PSA tests are often performed in older men.
Causes and risk factors
The exact cause of prostate cancer is not fully understood. The disease occurs when cells in the prostate gland develop genetic changes that cause them to begin to divide uncontrollably. Several factors influence the risk of being affected, and in most cases it is a combination of age, heredity, hormonal influences and lifestyle.
- Age – the strongest risk factor. The risk increases clearly after the age of 50 and the majority of cases are diagnosed in men over 65.
- Heredity – if a father or brother has had prostate cancer, the risk doubles. If several relatives are affected or the onset is early, the risk increases further.
- Genetic mutations – mutations in, for example, BRCA2 and certain other DNA repair genes are linked to increased risk and can result in more aggressive disease.
- Hormonal influences – testosterone and other male sex hormones stimulate the growth of prostate cells, which is a prerequisite for cancer to develop.
- Ethnicity – prostate cancer is more common and often more aggressive in men of African descent.
- Overweight and metabolic health – obesity, insulin resistance and metabolic syndrome have been linked to an increased risk of more aggressive forms of prostate cancer.
- Diet and lifestyle – high consumption of processed meat and low physical activity can affect the risk, although the connections are not entirely clear.
It is important to distinguish between the risk of developing prostate cancer and the risk of developing an aggressive form. Many men develop low-grade prostate cancer that never causes symptoms, while others develop a more rapidly growing disease that requires treatment.
Symptoms of prostate cancer
Prostate cancer often does not cause symptoms in the early stages. When symptoms do occur, they are usually due to the tumor affecting the urinary tract or having spread outside the prostate. The symptoms may be similar to those of benign prostatic hyperplasia, which is a very common and harmless condition in older men.
- Weak urine stream
- Difficulty starting urination
- Increased need to urinate, especially at night
- Feeling that the bladder is not emptying completely
- Burning or discomfort when urinating
- Blood in the urine or semen
- Pain in the pelvis, back, or hips (may indicate spread to the bones)
- Unexplained fatigue or weight loss
What type of pain can I experience with prostate cancer?
Pain is usually not an early symptom of prostate cancer, but usually only occurs when the disease is more advanced. If the cancer spreads to the bones, it can cause a dull, deep and persistent pain that is often located in the back, pelvis, hips or ribs. The pain can be constant, worsens with exertion and sometimes even feels more pronounced at night or at rest.
With locally advanced prostate cancer, some people may also experience a feeling of pressure or discomfort in the pelvic region. If the tumor affects the urinary tract, the pain can sometimes be experienced in connection with urination or give a feeling of heaviness in the lower abdomen.
How is the diagnosis made?
The aim of prostate cancer investigation is to detect the tumor, assess how aggressive it is and whether it has spread. The diagnosis is based on a combination of blood tests, clinical examination and diagnostic imaging. To definitively diagnose prostate cancer, a tissue sample (biopsy) is usually required.
- PSA test – a blood test that measures prostate-specific antigen. PSA can be elevated in prostate cancer but also in benign prostate enlargement, infection or inflammation.
- MRI of the prostate – often used when prostate cancer is suspected and provides a detailed image of the prostate tissue.
- Rectal palpation – the doctor examines the prostate through the rectum to feel for lumps or irregularities.
- Biopsy – tissue sample from the prostate that is analyzed under a microscope. This is required to confirm the diagnosis.
- Stage classification – if cancer is confirmed, CT scan, bone scintigraphy or PET scan can be used to see if the cancer has spread.
When prostate cancer is diagnosed, the aggressiveness of the tumor is often assessed using the Gleason score/ISUP grade as well as the PSA level and imaging findings, which help determine treatment.
Prognosis and treatment
The prognosis for prostate cancer varies depending on how early the disease is detected and how aggressive the tumor is. Many prostate cancers grow slowly and can be treated effectively, while other forms are more rapidly growing and require more extensive treatment.
Treatment is adjusted according to the stage of the tumor, the patient's age and general condition. In some cases, immediate treatment is not needed, but the disease is monitored closely.
- Active monitoring – used for low-risk prostate cancer where the tumor is considered to be growing slowly. The patient is followed regularly with PSA, MRI and sometimes biopsies.
- Surgery (radical prostatectomy) – the prostate is surgically removed, often in the case of localized cancer in patients with an expected long survival.
- Radiation therapy – can be given as an alternative to surgery or in combination with hormone therapy.
- Hormone therapy – lowers testosterone levels and slows the growth of the cancer. Often used in more advanced disease.
- Cytostatics and other drugs – can be used in the case of disseminated prostate cancer, sometimes together with modern targeted therapy.
- Palliative treatment – aims to relieve symptoms in advanced disease, for example pain relief in the case of bone metastases.
When prostate cancer is detected early, the prognosis is often good and many are cured. Therefore, it is important to investigate long-term urinary problems or elevated PSA, especially in men over 50 years of age or in cases of heredity.
