Prostate cancer is the second leading cause of cancer among adult males in the United States, after skin cancer. However, it is highly treatable, especially in the early stages.
Prostate cancer starts in the prostate gland, which is part of the male reproductive system. The gland produces a fluid that helps make up semen. Muscle cells inside the prostate play a role in ejaculation.
The American Cancer Society (ACS) expected that there would be
The ACS also notes that 1 in 8 males will receive a diagnosis of prostate cancer during their lifetime, and around 1 in 41 males will die from the disease. With treatment, there is a good chance of surviving prostate cancer.
Prostate cancer often produces no symptoms in the early stages. After a certain age, a doctor may recommend regular screening. A prostate exam can help detect cancer while it is still highly treatable, even if symptoms are not present.
Screening involves looking for early signs of disease in people who do not have any symptoms. Cancer screening aims to detect telltale changes at an early stage when treatment is more likely to be effective.
Doctors commonly use two main tests to screen for prostate cancer:
- the digital rectal exam (DRE)
- the prostate-specific antigen (PSA) test
Neither test can confirm that prostate cancer is present, as various other factors may influence results. However, these tests can indicate whether further steps are necessary.
A prostate biopsy is the only way to confirm that a person has prostate cancer.
Before undergoing either of these tests, the person will need to give consent, which involves confirming that they understand the potential benefits and risks.
- 50 years for males with an average risk and a life expectancy of more than 10 years
- 45 years for those with a high risk
- 40 years for people with more than one close relative (parent or sibling) who developed prostate cancer at an early age (younger than 65)
Who has a higher risk?
People may have a
- are non-Hispanic Black males
- are older males, as the average age at diagnosis is 66 years
- have one or more relatives with a history of prostate cancer
- follow a diet that is high in fat and highly processed carbohydrates
- have overweight or obesity
- have a sedentary (inactive) lifestyle
- have experienced exposure to Agent Orange
Black American males are almost 75% more likely to develop prostate cancer than white American males, and 2.2 times more likely to die as a result, according to the Prostate Cancer Foundation. The Foundation notes that, while experts do not know why the risk is higher for this group, the fatality rate is likely higher due to unequal access to healthcare and other socioeconomic factors.
In 2018, the U.S. Preventive Services Task Force recommended that the decision to undergo screening from the ages of 55–69 years should be up to the individual. This is because screening can lead to false-positive results, which may result in unnecessary biopsies. It can also lead to overtreatment of low risk disease.
Before going ahead with screening, a person should discuss the risks and benefits with their doctor.
The DRE is a physical examination for changes in the prostate that could indicate a tumor.
Before the DRE
Common questions to ask before a DRE include:
- What will happen during the DRE?
- How long will it take?
- Will it be painful?
- How accurate is a DRE, in terms of finding cancer?
- What will happen next?
If the person has insurance, they should also ask their insurance provider about coverage and whether there will be additional costs.
During the DRE
The procedure usually requires the person to undress from the waist down.
The specialist may instruct the person to lie on their left side and pull their knees up to their chest or stand and lean against a table.
The specialist will:
- put on gloves and put lubricant on one finger
- assess the area around the rectum for anything unusual
- gently insert a lubricated, gloved finger into the rectum
- feel the prostate to assess the size and check for bumps, soft or hard spots, and other abnormalities
A DRE is not usually painful, but it may be slightly uncomfortable. It takes only a few minutes to complete.
After the DRE
After the exam, the doctor will explain the results.
The person can usually go back to their regular activities immediately after a DRE.
The doctor will usually explain the results of the DRE after the exam.
The person may also undergo a PSA test on the same day. If the doctor believes that further steps may be necessary, they will base this on the results of both the PSA and DRE.
It is worth noting that a DRE can often produce a
Prostate nodules can develop because of prostate cancer or other prostate-related conditions.
This blood test measures the amount of PSA (prostate-specific antigen) that the prostate gland produces. Some of this antigen leaks into the blood and will show up during testing.
High levels of PSA in the blood can indicate prostate cancer, but various other conditions and factors can raise PSA levels. High levels do not necessarily mean cancer is present.
What does the PSA test involve?
The PSA test involves taking a blood sample and sending it to a laboratory for analysis. The results indicate:
- Normal levels: Most healthy adult males have PSA levels
below 4 nanogramsper milliliter (ng/ml).
- Borderline levels: PSA levels of 4–10 ng/ml are borderline. There is a 25% chance that cancer is present, and the person will usually need additional tests.
- High levels: If PSA levels are over 10 ng/ml, there is a 50% chance that the person has prostate cancer. The specialist will likely recommend more testing, including a prostate biopsy.
It is important to note that PSA levels can naturally vary from person to person. A person with high levels may not have prostate cancer. On the other hand, about
Prostate cancer is not the only cause of high PSA levels. Find out more about the other causes here.
What do the results mean?
PSA levels may be above the baseline for various reasons other than prostate cancer.
- older age
- recent ejaculation
- medical procedures, including a DRE, a biopsy, or some urological investigations
- testosterone supplementation
- an enlarged prostate — because of benign prostatic hyperplasia (BPH), for example
- prostatitis, which is inflammation and swelling of the prostate
Also, people with obesity may have lower PSA readings.
In addition, some medications may reduce PSA levels, including:
- 5-alpha-reductase inhibitors, which can help treat BPH
- aspirin, which some people take regularly as a blood thinner
- statins, which help manage cholesterol levels
- thiazide diuretics, a kind of water pill that can help reduce high blood pressure
Some herbal medicines and supplements can also lower PSA levels. A person should tell their doctor about any medications and supplements they take before undergoing the test.
High PSA levels alone do not indicate cancer. However, if a DRE also reveals changes, a doctor may recommend a biopsy for a more accurate result.
Some newer tests
The Prostate Health Index (PHI) combines the results of:
- total PSA
- free PSA
The 4Kscore test combines the results of various factors, such as:
- total PSA
- free PSA
- intact PSA
- human kallikrein 2 (hK2)
What happens next?
If the DRE and PSA tests show nothing unusual, the healthcare professional may recommend monitoring by repeating one or both tests every
If the results could indicate prostate cancer, the doctor may recommend a biopsy.
A prostate biopsy can lead to complications. What are the alternatives?
A prostate exam and a colonoscopy are both ways of examining the rectum, but for different purposes. A colonoscopy does not check for prostate cancer. The two tests also involve different procedures, as outlined in the table below:
|Aim||to detect changes in the prostate gland that could indicate prostate cancer||to detect polyps and other changes in the colon that could indicate colon cancer|
|What it involves||in a DRE, the doctor uses a gloved finger to feel for changes; they may also carry out a PSA blood test||the doctor inserts a colonoscope, a thin tube with a lighted camera, to take images from inside the large intestine|
|Who needs it?||males aged ||depending on risk factors, males and females aged 45–75 years and possibly beyond; those with a higher risk may |
However, when a doctor carries out a colonoscopy, they usually start with a DRE. In patients with a prostate, this is an opportunity for the doctor to check the prostate gland at the same time, according to 2018 research. If a person is due to have a colonoscopy, they may wish to speak with their doctor about checking the prostate gland at the same time.
Prostate cancer is common. However, if a doctor diagnoses cancer while it remains in the prostate or nearby and the person receives treatment, it is
If cancer spreads to other parts of the body, this survival rate falls to 30%.
A person should start asking about the benefits of screening after age 50, or earlier, if they have a higher risk of prostate cancer.
If so many factors can influence DRE and PSA test results, how does the doctor decide whether to recommend a biopsy?MNT Editorial Staff
The doctor and the individual should make the decision about a biopsy together, based on the DRE and PSA results and any additional useful data.
A single elevated PSA value should be taken in context. Often it is helpful to consider an elevated value in reference to prior values for the same patient. For instance, a PSA of 4.5 that has been stable for many years is less likely to indicate cancer than a value that has risen from 2 to 4 to 6 in a couple of years.
It is also helpful to take prostate size into consideration, which allows the physician to calculate a PSA density (PSA per unit of prostate). Many studies have shown that a higher PSA density is more likely to indicate cancer.
In modern practice, a multi-parametric prostate MRI is extremely helpful for stratifying patients for biopsy. This test not only allows identification of high suspicion areas within the prostate, but can be complexed with MRI / ultrasound fusion biopsy platforms to allow for targeted biopsy, which vastly increases the accuracy of prostate biopsy.Joseph Brito, MDAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.