What is cancer screening?
Cancer screenings are recommended for people to stay in control of their own health. While you may not have any particular symptoms, screenings can identify the presence of cancer even in the absence of any physical indicators. Screenings allow for early detection and diagnosis which results in earlier treatment. This is especially important because by the time symptoms are present, the cancer may have already begun the process of spreading, making treatment more of a challenge.
The medical community has made great strides in identifying certain risk factors associated with cancers of all kind. The presence of these risk factors indicates what types of screenings should be done and how often. But we are still trying to better understand what causes some people to be more likely to be diagnosed with cancer. Research continues in this area and will ultimately determine more accurate screening recommendations.
Screenings are a normal part of routine healthcare and are begun at certain ages to establish a baseline so that if cancer does develop, changes will be identified easier during screenings.
Further tests are ordered if screening findings are outside of normal limits. These are referred to as diagnostic tests.
What are the diagnostic tests for prostate cancer?
Abnormal findings from any of these tests can help diagnose a problem and suggest the next steps to take:
- Digital Rectal Exam (DRE) – a physical examination of the prostate by a doctor. This is done in a doctor’s office at which time the doctor inserts a gloved finger into the rectum. Through the rectum wall the doctor can feel the prostate and determine if there are any hard or lumpy areas.
- Prostate Specific Antigen (PSA) – a blood test that measures the levels of PSA in the blood. PSA is a protein that is specifically produced by the prostate gland. Low levels of PSA are normally found in the blood stream but when levels are found to be higher, this can indicate the presence of an abnormality including tumor. It should be noted however, that only 25% to 30% of men who test high for PSA in their bloodstream actually turn out to have prostate cancer. The results of a PSA test may simply indicate whether further testing is warranted.
- Biopsy – in which tissue samples are removed to test for cancer.
The digital rectal exam and the PSA test can be used to screen for prostate cancer even if symptoms are not present, while a biopsy is done when the presence of cancer is suspected.
How reliable are the screening tests for prostate cancer?
Neither the DRE or PSE is a perfect means for identifying prostate cancer. Even during a digital rectal exam, abnormalities may be missed by the doctor. A PSA can be difficult to use as a marker because even men without prostate cancer can have elevated PSA levels. That’s why, often, the most accurate results are found by using a combination of the two tests.
Why is the PSA test performed?
The PSA and DRE tests are recommended for men age 50 and older by the U.S. Food and Drug Administration (FDA) as a method for detecting prostate cancer.
An elevated PSA level does not necessarily indicate the presence of prostate cancer but may help the doctor determine if further tests need to be done.
In addition to being used as a screening process for prostate cancer, the PSA has also been approved by the FDA as a method for monitoring patients who have a prior history of prostate cancer so that they can be screened for any recurrence of the disease. Again, an elevated PSA does not mean the return of prostate cancer but it can be a way for the doctor to make recommendations for further testing.
While it is important to note that PSA levels may be high even in the absence of cancer, it is also important to recognize that PSA levels may be falsely low in some cases including when a man is receiving hormone therapy to treat his prostate cancer. In this case, a PSA may not be an accurate indicator of true PSA levels in a man’s bloodstream and it may be advised that testing be put off until hormone therapy is completed.
Who should have a PSA screening test?
Screening recommendations vary from doctor to doctor. While some doctors may recommend a yearly screening for men once they turn 50, others recommend screening at an earlier age (40-45) if they have certain risk factors. It’s important for patients to work with their doctors to determine the recommendations for their particular situation as well as working with their individual insurance companies to determine what screenings are covered and at what age.
The risk factors that are taken into consideration by doctors when determining screening recommendations include age (most occurrences of prostate cancer are in men older than age 65), a diet high in fat (especially animal fat), family history (a father or brother with prostate cancer), and even race (African American men have the highest risk of developing prostate cancer followed by white men, while Asian and Native American men have the lowest risks).
How are PSA test results reported?
The PSA test measures the amount of PSA protein in the bloodstream and are reported as nanograms of PSA present per milliliter of blood. The resulting measurement is ng/ml. The following ranges of PSA are commonly used by doctors as a grading system:
0 to 2.5 ng/ml – considered low level
2.6 to 10 ng/ml – slightly to moderately elevated level
10 to 19.9 ng/ml – a moderately elevated level
20 ng/ml or more – considered to be a significantly elevated level
There are no “normal” levels of PSA. Rather, a doctor may be alerted to continue with further testing if a man’s PSA levels are high or start to elevate over time as compared with their baseline level established during a first screening.
What are some of the limitations of the PSA test?
The PSA test can be an effective tool in helping doctors determine if further testing should be done to determine the presence of prostate cancer. But it should be noted that there are limitations to the test including:
False Positives – This can happen quite often because high levels of PSA in the bloodstream does not necessarily indicate the presence of cancer. Of course, false positives can result in further testing causing increased costs, increased anxiety for the patient, and the possibility of going through more invasive testing for little reason. In fact, only up to 30% of men who undergo biopsies due to the results received from PSA level testing wind up actually having prostate cancer.
False Negatives – Just as levels of PSA can be high when cancer is not present, they can also be in the lower range when cancer does in fact exist. Prostate cancer is a slow-growing disease and symptoms, including elevated PSA levels, are often delayed in being noticeable.
Inability to Have Much Impact – Smaller prostate tumors are very slow-growing and may not ever produce symptoms or cause any health risk whatsoever. Elevated PSA levels and further testing will not have any impact on this and will only serve to identify the presence of cancer that is very unlikely to cause any health problems to a man during his lifetime. Conversely, if elevated PSA levels are identified in a man with a fast-growing prostate cancer, there is the possibility that the disease has already spread to other parts of the body.
What if the test results show an elevated PSA level?
This is not to say that elevated PSA levels should ever be ignored. It’s important to discuss the possibilities for an elevated PSA test result – which may include benign and very common conditions such as prostate enlargement, inflammation, infection, etc. – and determine if further testing may be in order.
If there are no other symptoms present, your doctor may recommend a “wait and watch” plan in which regular DRE and PSA tests are conducted on a regular basis to keep a lookout for any changes.
To rule out other conditions that may be causing elevated PSA levels, a doctor may recommend other tests such as a urine test, imaging tests including x-ray, ultrasound, cystoscopy, etc. If there is evidence of enlarged prostate, inflammation, or infection, then a treatment plan will be put into place to manage and/or cure the condition which may include medication or surgery.
However, if, based on other factors combined with the elevated PSA levels, the doctor suspects evidence of prostate cancer, a biopsy may be ordered. During a biopsy, samples of tissue are removed from the prostate and examined under a microscope for evidence of cancer cells.
The controversy of the PSA test
Screening tests are used to test for prostate cancer with the goal of identifying disease earlier and ultimately saving lives. The PSA test continues to be a controversial screening process because it is yet unclear whether the test saves lives. Because elevated PSA levels can indicate a variety of conditions, experts are concerned that a high level test finding can result in unnecessary follow-up procedures for men who wind up not having prostate cancer at all. Even when cancer is detected, most are so small that they are unlikely to ever cause a health risk. However, the follow-up testing or treatment (including surgery or radiation) that men undergo because of their PSA results can be a health risk.
For instance, when PSA levels are elevated, a prostate biopsy may be ordered during which tissue is removed from the prostate and examined under a microscope to look for evidence of disease. The side effects from the biopsy can include some bleeding and even the potential for infection. And treatment for a prostate cancer that may not ever pose any risk could include terrible side effects including incontinence, erectile dysfunction, and more. Experts are concerned that PSA testing is resulting in over-diagnosis which does more harm than good.
As a result, research continues to be done to improve the accuracy and validity of the PSA test and the benefits of the test itself are under much scrutiny by the National Cancer Institute in their ongoing quest for better testing to save lives. To that end, a variety of new methods for examining PSA levels are currently being thoroughly researched.
Should I seek a second opinion?
Once testing has been complete, the results are in, and a course of treatment has been recommended, it’s important to ensure that you have had all your questions answered (see a full list of common questions to ask your doctor here).
A second opinion is always encouraged to help you to have all the information you need to make the best decision regarding your health care. Having another opinion can help you confirm that you are making the best decision regarding treatment or allow you to adjust your plan accordingly. Another doctor may also better help you understand answers to certain questions and even offer information regarding clinical trials for prostate cancer treatment for which you may be appropriate.
It may also be helpful to reach out for peer support from others who have gone through similar experiences. Support groups for men who have been diagnosed with prostate cancer can be invaluable in connecting you with others who understand what you’re going through and can offer insight into particular treatment procedures.