Prostate Cancer

Written by on June 22, 2021

Prostate

The prostate is a walnut-sized gland located behind the base of the penis, in front of the rectum, and below the bladder. It surrounds the urethra, the tube-like channel that carries urine and semen through the penis. The prostate’s main function is to make seminal fluid, the liquid in semen that protects, supports, and helps transport sperm.

The prostate continues to enlarge as people age. This can lead to a condition called benign prostatic hypertrophy (BPH), which is when the urethra becomes blocked. BPH is a common condition associated with growing older, and it has not been associated with a greater risk of having prostate cancer.

What is prostate cancer?

The prostate is a gland that is only found in men. It is about the size of a walnut and is found beneath the bladder.

The prostate makes fluid that protects the urethra (the tube that carries urine and sperm out of the body) and helps sperm survive.

Prostate cancer develops when a cell in the prostate gland gets damaged and starts to grow in an uncontrolled way.

 

How common is prostate cancer?

More than 130 cases of prostate cancer are diagnosed every day in the UK, making it the most common cancer in men. In 2017, 48,561 cases of prostate cancer were diagnosed*.

Who is most at risk of prostate cancer?

As with all cancers, the risk of developing prostate cancer depends on a number of factors and varies from person to person. About three out of every four cases of prostate cancer are diagnosed in men aged 65 and over. These are some of the most important factors.

There is strong evidence that being overweight or obese is a cause of advanced prostate cancers, including aggressive prostate cancers, which can be fatal.

  • Age

Men under the age of 50 have a very low risk of prostate cancer. The risk increases as you get older. Most men in their 80s will have some degree of prostate cancer, but it is often not life-limiting.

  • Family history

Your risk is higher if you have a close relative (for example, your father, brother or uncle) who has been affected by the disease. There is also evidence which shows that having a close female relative (for example, your mother) who has had breast cancer can increase your risk. Experts believe that around 5–9 per cent of prostate cancer cases are linked to genes or family history.

  • Ethnicity

Men of African-Caribbean or African descent have a higher risk of prostate cancer than white men. Asian and Chinese men have a lower risk than white men.

Prostate Cancer

Cancer begins when healthy cells in the prostate change and grow out of control, forming a tumor. A tumor can be cancerous or benign. A cancerous tumor is malignant, meaning it can grow and spread to other parts of the body. A benign tumor means the tumor can grow but will not spread.

Prostate cancer is somewhat unusual when compared with other types of cancer. This is because many prostate tumors do not spread quickly to other parts of the body. Some prostate cancers grow very slowly and may not cause symptoms or problems for years or ever. Even when prostate cancer has spread to other parts of the body, it often can be managed for a long time. So people with prostate cancer, and even those with advanced prostate cancer, may live with good health and quality of life for many years. However, if the cancer cannot be well controlled with existing treatments, it can cause symptoms like pain and fatigue and can sometimes lead to death. An important part of managing prostate cancer is monitoring it for growth over time, in order to find out if it is growing slowly or quickly. Based on the pattern of growth, your doctor can decide the best available treatment options and when to give them.

Histology is how cancer cells look under a microscope. The most common histology found in prostate cancer is called adenocarcinoma. Other, less common histologic types include neuroendocrine prostate cancer and small cell prostate cancer. These rare variants tend to be more aggressive, produce much less PSA, and spread outside the prostate earlier. Read more about neuroendocrine tumors.

 

Prostate-Specific Antigen (PSA)

Prostate-specific antigen (PSA) is a protein produced by cells in the prostate gland and released into the bloodstream. PSA levels are measured using a blood test. Although there is no such thing as a “normal PSA” for anyone at any given age, a higher-than-normal level of PSA can be found in people with prostate cancer. Other non-cancerous prostate conditions, such as BPH (see above) or prostatitis can also lead to an elevated PSA level. Prostatitis is the inflammation or infection of the prostate. In addition, some activities like ejaculation can temporarily increase PSA levels. Ejaculations should be avoided before a PSA test to avoid falsely elevated tests. People should discuss with their primary care doctor the pros and cons of PSA testing before using it to screen for prostate cancer. See the Screening section for more information.

 

Prostate Cancer: Risk Factors and Prevention

A risk factor is anything that increases a person’s chance of developing cancer. Although risk factors often influence the chance to develop cancer, most do not directly or by themselves cause cancer. Some people with several known risk factors never develop cancer, while others with no known risk factors do. Knowing your risk factors and talking about them with your doctor may help you make more informed lifestyle and health care choices.

The following factors may raise a man’s risk of developing prostate cancer:

  • Age. The risk of prostate cancer increases with age, especially after age 50. Around 60% of prostate cancers are diagnosed in people who are 65 or older. Older adults who are diagnosed with prostate cancer can face unique challenges, specifically with regard to cancer treatment. For more information, please visit Cancer.Net’s section about aging and cancer.
  • Race. Black men in the United States, and other men of African ancestry, are diagnosed with prostate cancer more than men of other races. Black men are more likely to die from prostate cancer than white men.
  • Location. Prostate cancer occurs most often in North America and northern Europe. It also appears that prostate cancer is increasing among Asian people living in urbanized environments, such as Hong Kong, Singapore, and North American and European cities, particularly among those who have a lifestyle with less physical activity and a less healthy diet.
  • Family history. Prostate cancer that runs in a family, called familial prostate cancer, makes up about 20% of all prostate cancers. This type of prostate cancer develops because of a combination of shared genes and shared environmental or lifestyle factors.Hereditary prostate cancer, which is inheriting the risk from a relative, is rare and accounts for about 5% of all cases. Hereditary prostate cancer occurs when changes in genes, or mutations, are passed down within a family from 1 generation to the next. Hereditary prostate cancer may be suspected if a family history includes any of the following characteristics:
    • 3 or more first-degree relatives with prostate cancer
    • Prostate cancer in 3 generations on the same side of the family
    • 2 or more close relatives, such as a parent, sibling, child, grandparent, uncle, or nephew, on the same side of the family diagnosed with prostate cancer before age 55

    If someone has a first-degree relative—meaning a parent, sibling, or child—with prostate cancer, their risk of developing prostate cancer is 2 to 3 times higher than the average risk. This risk increases even further with the number of relatives diagnosed with prostate cancer.

Prevention

Different factors cause different types of cancer. Researchers continue to look into what factors cause prostate cancer, including ways to prevent it. Although there is no proven way to completely prevent prostate cancer, you may be able to lower your risk. Talk with your health care team for more information about your personal risk of cancer.

Chemoprevention

A class of drugs called 5-alpha-reductase inhibitors (5-ARIs), which includes dutasteride (Avodart) and finasteride (Proscar), are often used to treat BPH. They may also lower a man’s risk of developing prostate cancer. Some previous clinical trials suggested that 5-ARIs were linked to more aggressive prostate cancers, but newer studies have suggested that this is not true. According to the results of a long-term follow-up study published in 2013, 78% of people either taking finasteride or a placebo were still alive 15 years later. These results suggest that taking finasteride does not lower the risk of death for those with prostate cancer. The U.S. Food and Drug Administration (FDA) has not approved these drugs for the prevention of prostate cancer. However, a 5-ARI is approved by the FDA for the treatment of lower urinary tract symptoms associated with BPH.

The decision to take a 5-ARI is different for each person. Anyone considering taking this class of medication should discuss the possible benefits and side effects with their doctor.

Dietary changes

There is not enough information right now to make clear recommendations about the exact role eating behaviors play in prostate cancer. Dietary changes may need to be made many years earlier in a person’s life to reduce the risk of developing prostate cancer later in life.

Here is a brief summary of the current research:

  • In some studies, regularly eating foods high in fat, especially animal fat, has been associated with increased prostate cancer risk. However, no prospective studies have yet proven that diets high in animal fat raise the risk of prostate cancer. Prospective studies look at people who follow either high-fat or low-fat diets and then measure the total number of people in each group who are diagnosed with prostate cancer.
  • A diet high in vegetables, fruits, and legumes, such as beans and peas, may lower the risk of prostate cancer. It is unclear which nutrients are directly responsible. Although lycopene, a nutrient found in tomatoes and other vegetables, has been shown to be associated with a lower risk of prostate cancer, the data have not proven that there is a relationship between lycopene and preventing cancer.
  • Currently no specific vitamins, minerals, or other supplements have been shown in clinical trials to prevent prostate cancer. Talk with your doctor before taking any supplements to prevent prostate cancer.
  • Specific changes to eating behaviors may not stop or slow the development of prostate cancer. It is possible such changes would need to be made early in life to have an effect.

Prostate Cancer: Screening

Screening is used to look for cancer before you have any symptoms or signs. When cancer is found earlier in its development, it is often at an earlier stage. This means that there is a better chance of successfully treating the cancer. Scientists have developed, and continue to develop, tests that can be used to screen a person for specific types of cancer. The overall goals of cancer screening are to:

  • Lower the number of people who die from the disease, or eliminate deaths from cancer altogether
  • Lower the number of people who develop the disease

Learn more about the basics of cancer screening.

Screening information for prostate cancer

Screening for prostate cancer is done to find evidence of cancer in otherwise healthy adults. Two tests are commonly used to screen for prostate cancer:

  • Digital rectal examination (DRE). A DRE is a test in which the doctor inserts a gloved, lubricated finger into the rectum and feels the surface of the prostate through the bowel wall for any irregularities.
  • PSA blood test. There is controversy about using the PSA test to look for prostate cancer in people with no symptoms of the disease. On the one hand, the PSA test is useful for detecting early-stage prostate cancer, especially in those with many risk factors, which helps some get the treatment they need before the cancer grows and spreads. On the other hand, PSA screening may find very-slow-growing prostate cancers that would never threaten someone’s life. As a result, screening for prostate cancer using PSA may lead to treatments that are not needed, which can cause side effects and seriously affect a person’s quality of life.

Prostate Cancer: Symptoms and Signs

The symptoms and signs of prostate cancer may include:

  • Frequent urination
  • Weak or interrupted urine flow or the need to strain to empty the bladder
  • The urge to urinate frequently at night
  • Blood in the urine
  • New onset of erectile dysfunction
  • Pain or burning during urination, which is much less common
  • Discomfort or pain when sitting, caused by an enlarged prostate

Other noncancerous conditions of the prostate, such as BPH or an enlarged prostate, can cause similar symptoms. Or, the cause of a symptom may be a different medical condition that is also not related to cancer. Urinary symptoms also can be caused by an infection of the bladder or other conditions.

If cancer has spread outside of the prostate gland, symptoms may include:

  • Pain in the back, hips, thighs, shoulders, or other bones
  • Swelling or fluid buildup in the legs or feet
  • Unexplained weight loss
  • Fatigue
  • Change in bowel habits

If you are concerned about any changes you experience, please talk with your doctor. Your doctor will ask how long and how often you have been experiencing the symptom(s), in addition to other questions. This is to help figure out the cause of the problem, called a diagnosis.

If cancer is diagnosed, relieving symptoms remains an important part of cancer care and treatment. This may be called palliative care or supportive care. It is often started soon after diagnosis and continued throughout treatment. Be sure to talk with your health care team about the symptoms you experience, including any new symptoms or a change in symptoms.

 

Prostate Cancer: Diagnosis

Doctors use many tests to find, or diagnose, cancer. They also do tests to learn if cancer has spread to another part of the body from where it started. If this happens, it is called metastasis. For example, imaging tests can show if the cancer has spread. Imaging tests show pictures of the inside of the body. Doctors may also do tests to learn which treatments could work best.

For most types of cancer, a biopsy is the only sure way for the doctor to know if an area of the body has cancer. In a biopsy, the doctor takes a small sample of tissue for testing in a laboratory.

This section describes options for diagnosing prostate cancer. Not all tests listed below are commonly used for every person. Your doctor may consider these factors when choosing a diagnostic test:

  • The type of cancer suspected
  • Your signs and symptoms
  • Your age and general health
  • The results of earlier medical tests

Early tests

If prostate cancer is suspected, a physical examination and the following tests may be used to decide if more diagnostic tests are needed:

PSA test. As described in the Introduction and Screening sections, PSA is a type of protein released by prostate tissue that is found in higher levels in blood. Levels can be raised when there is abnormal activity in the prostate, including prostate cancer, BPH, or inflammation of the prostate. Doctors can look at features of the PSA value to decide if a biopsy is needed, such as absolute level, change over time (also known as “PSA velocity”), and level in relation to prostate size.

Free PSA test. There is a version of the PSA test that allows the doctor to measure a specific component, called the “free” PSA. Free PSA is found in the bloodstream and is not bound to proteins. A standard PSA test measures total PSA, which includes both PSA that is and is not bound to proteins. The free PSA test measures the ratio of free PSA to total PSA. Knowing this ratio or percent can sometimes help find out if an elevated PSA level is more likely to be caused by a malignant condition like prostate cancer.

DRE. A doctor uses a DRE to find abnormal parts of the prostate by feeling the area using a finger. It is not very precise and not every doctor has expertise in the technique; therefore, DRE does not usually detect early prostate cancer. See the Screening section for more information.

Biomarker tests. A biomarker is a substance that is found in the blood, urine, or body tissues of a person with cancer. It is made by the tumor or by the body in response to the cancer. A biomarker may also be called a tumor marker. Biomarker tests for prostate cancer include the 4Kscore, which predicts the chances someone will develop high-risk prostate cancer, and the Prostate Health Index (PHI), which predicts the chances someone will develop prostate cancer.

For people diagnosed with prostate cancer by biopsy, there are times when a genomic test, such as Oncotype Dx Prostate, Prolaris, Decipher, and ProMark, can provide additional information to inform a decision about how the prostate cancer is managed. This includes when those with certain low-risk or intermediate-risk localized prostate cancer are considering active surveillance (see Types of Treatment). It also may include using the Decipher test to help decide whether more treatment should be considered in certain patients following surgical removal of the prostate, called prostatectomy. If a biomarker test is used, the results should always be evaluated in combination with all other available information.

Talk with your doctor for more information about biomarker tests, what they mean, and how the results might or might not affect your treatment plan.

Making a diagnosis

If the PSA or DRE test results are abnormal, then further tests will be used to confirm whether a person has prostate cancer. Many tests can suggest that cancer is present, but only a biopsy can make a definite diagnosis.

Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. To get a tissue sample, a surgeon most often uses transrectal ultrasound (TRUS, see below) and a biopsy tool to take very small slivers of prostate tissue. Biopsy specimens will be taken from several areas of the prostate. This is done to make sure that a good sample is taken for examination. Most people will have 12 to 14 pieces of tissue removed, and the procedure can take 20 to 30 minutes to complete.

This procedure is usually done at the hospital or doctor’s office without needing to stay overnight. The patient is given local anesthesia beforehand to numb the area and usually receives antibiotics before the procedure to prevent infection. The ultrasound tool is inserted into the rectum and then the biopsy needle is passed through the rectum and into the prostate gland to collect tissue samples.

There is a risk of infection associated with transrectal prostate biopsy, which is why some doctors choose to use transperineal prostate biopsy instead. This biopsy is also guided by TRUS, but the biopsy needle goes through the skin of the perineum and into the prostate gland. The perineum is the space between the scrotum and the anus. By passing the needle through the skin instead of the rectum, this procedure lowers the risk of infection.

A pathologist then analyzes the sample(s) under a microscope. A pathologist is a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease.

Ask to review the results of the pathology report with your health care team.

MRI fusion biopsy. An MRI fusion biopsy combines an MRI scan (see below) with TRUS. Evaluation with a prostate MRI scan has become a routine procedure in clinical practice. The patient first receives an MRI scan to identify suspicious areas of the prostate that require further evaluation. The patient then has an ultrasound of the prostate. Computer software combines these images to produce a 3D image that helps target a precise area for the biopsy. Although it may not eliminate the need for repeat biopsies, an MRI fusion biopsy can better identify areas that are more likely to be cancerous than other methods. An MRI fusion biopsy should only be performed by someone with expertise in the procedure.

Transrectal ultrasound (TRUS). A doctor inserts a probe into the rectum that takes a picture of the prostate using sound waves that bounce off the prostate. A TRUS is usually done at the same time as a biopsy.

Finding out if the cancer has spread

To find out if cancer has spread outside of the prostate, doctors may perform the imaging tests listed below. Doctors are able to estimate the risk of spread, called metastasis, based on PSA levels, tumor grade, and other factors, but an imaging test can confirm and provide information about the cancer’s location.

Imaging tests may not always be needed. A CT scan or bone scan may not be necessary for those with no symptoms and low-risk, early-stage prostate cancer, as determined with information from the PSA test and biopsy. Learn more about when these tests are recommended to find out if the cancer has spread.

For people with advanced prostate cancer, ASCO recommends that 1 or more of the imaging tests below be done to provide more information about the disease and help plan the best treatment. This includes when there is a newly diagnosed, high-risk cancer; if metastasis is suspected or confirmed; if the cancer has returned following treatment; or when the cancer grows during the treatment period. Learn more about this guideline on the ASCO website.

Whole-body bone scan. A bone scan uses a radioactive tracer (Technetium-99) to look at the inside of the bones. The tracer is injected into a patient’s vein. It collects in areas of the bone where metabolic activity has occurred. Healthy bone appears lighter to the camera, and areas of injury, such as those caused by cancer, stand out on the image. It is important to know that structural changes to the bone, such arthritis or bone injuries like fractures, can also be interpreted as abnormal and need to be evaluated by a doctor to make sure they are not cancer.

Computed tomography (CT or CAT) scan. A CT scan takes pictures of the inside of the body using x-rays taken from different angles. A computer combines these pictures into a detailed, 3-dimensional image that shows any abnormalities or tumors. A CT scan can be used to measure the tumor’s size. Sometimes, a special dye called a contrast medium is given before the scan to provide better detail on the image. This dye can be injected into a patient’s vein or given as a pill or liquid to swallow.

Magnetic resonance imaging (MRI). An MRI scan uses magnetic fields, not x-rays, to produce detailed images of the body. An MRI can be used to measure the tumor’s size, and a scan can focus specifically on the area of the prostate or on the whole body. A special dye called contrast medium is given before the scan to create a clearer picture, which is injected into a patient’s vein.

Positron emission tomography (PET) or PET-CT scan (updated 06/2021). A PET scan is usually combined with a CT scan (see above), called a PET-CT scan. However, you may hear your doctor refer to this procedure just as a PET scan. A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive substance is injected into the patient’s body. This substance is taken up by cells that use the most energy or are more biologically active. Because cancer tends to use energy and is biologically active, it absorbs more of the radioactive substance. A scanner then detects this substance to produce images of the inside of the body. For many types of cancer, a PET-CT scan uses fluorodeoxyglucose (FDG) as the substance that is imaged; however, FDG is not a useful substance for initial imaging in prostate cancer and should not be routinely used. If metastasis or recurrence are suspected, a PET scan using gallium-68 PSMA-11 or 18F-DCFPyL may be recommended. In this type of scan, the gallium-68 or fluorine-18 binds to prostate-specific membrane antigen (PSMA), which is often at higher levels in prostate cancer cells, and shows places where the cancer has spread.

Researchers are investigating using different substances with PET scans to find prostate cancer. For example, sodium fluoride is absorbed by bones, and its use in a PET scan may improve the chances of finding prostate cancer that has spread to the bone. Other substances being studied include choline acetate and fluciclovine.

After diagnostic tests are done, your doctor will review all of the results with you. If the diagnosis is cancer, these results also help the doctor describe the cancer. This is called staging.

How can you reduce your risk of prostate cancer?

The most up-to-date research shows that if you are overweight or obese you are at greater risk of advanced prostate cancer. To find out if you’re a healthy weight for your height, check your body mass index (BMI) using our BMI calculator.

Visit NHS Choices to find out about the symptoms and treatment of prostate cancer.

 


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