Diagnostic Protocols For Prostate Cancer

Are you aware that each year more than 129.4 per 100,000 new cases of prostate cancer are reported in the United States alone? Despite excellent prognosis and quality treatment, prostate malignancy claims 20.7 cancer sufferers per 100,000 each year (1). Experts suggests that early diagnosis can reduce the risk of morbidity and mortality in patients.

The identification of prostate malignancy involves two types of tests:

• Screening tests are performed in otherwise healthy individuals with mild or no symptoms of cancer. Most frequently employed prostate cancer screening tests include; assessment of PSA levels and digital rectal examination (DRE).
• Confirmatory tests are performed to confirm the presence or absence of prostate malignancy in individuals with abnormal results of screening tests. Most commonly recommended confirmatory tests include; ultrasonography and biopsy.

Screening For Prostate Cancer

Serum levels of Prostate Specific Antigen (PSA) are used to screen patients for prostate cancer. It is ideally recommended to get screened after 40 -50 years of age (or even earlier if you have certain risk factors that makes you more likely to get the cancer). But there is no general consensus. For example:

• Mayo Clinic recommends annual PSA screening and DRE (digital rectal examination) for men between 50-70 years of age, with a life expectancy more than 10 years. Prostate cancer screening should be done earlier in men who have 2 or more risk factors.
• According to American Cancer Society (ACS), men who are 50 years old and have average risk of developing prostate cancer should take the decision for screening after weighing risks and benefits of PSA screening. Those who are 45 years old and are at high risk of developing prostate cancer or those who are 40 years old and have very high risk for prostate cancer should make an informed decision in the favor of PSA testing after carefully analyzing pros and cons.

Does Normal PSA Levels Mean I am Cancer-Free?

High serum PSA levels are usually suggestive of prostate cancer, but normal PSA levels doesn’t necessarily mean that there is no cancer. This happens in some cases, when prostate cancer grows very quickly. Such condition is referred to as ‘false negative’ i.e. you have prostate cancer but test results are showing that you do not have cancer.

Since PSA screening is very complex therefore, you must consult a doctor who has expertise in interpreting PSA levels.

What Are Some Classic Advantages Of PSA Test?

• Early diagnosis through PSA screening can help in preventing severe consequences. Prompt diagnosis and early treatment is a life saver (especially because the prognosis of prostate cancer is highly favorable).
• Early diagnosis means that you will need less aggressive treatment which will minimize serious side effects such as erectile dysfunction or incontinence (that are common with advanced illness).
• Early diagnosis of prostate cancer can also prevent distant spread/ metastasis to other organs.

What Are Some Classic Disadvantages Of PSA Test?

• There is always a risk of false-positive results
• Follow-ups are stressful, time-consuming and expensive
• Individuals who undergo PSA screening often develops fear, agitation and frustration.

2. Digital Rectal Examination

Besides PSA screening there are other diagnostic tools as well for the detection of prostate cancer. Digital rectal examination involves insertion of a gloved lubricated finger in the rectum to feel the posterior border and edges of prostate gland. During DRE, your doctor also looks for:

• Size of the gland
• Presence of any bumps or irregularities along the edges or borders of prostate gland.

Digital rectal examination has two benefits over PSA. Along with prostate cancer it can also help in diagnosing rectal cancers. Moreover, it is a safe, easy and less expensive test. Yet, some people find it embarrassing and uncomfortable.

What Are Some Confirmatory Tests For Prostate Cancer?

These tests are usually performed as the second set of investigations to confirm the presence of cancer as well as other information regarding the tumor (such as size, morphology, location etc.)

1. Ultrasound:

Investigators utilize ultrasonic radiations to obtain the exact shape, size and morphology of prostate gland to see:

• If there are any physiological or pathological anomalies (such as bumps, irregularities of edges, borders etc.)
• The physiology of surrounding tissues

Ultrasound of prostate gland is performed by a small cigar shaped probe that is inserted via rectum to obtain clear images.

2. Prostate Biopsy:

Biopsy of prostate gland under ultrasound guidance is the gold-standard diagnostic procedure. It involves extraction of a small piece of gland via needle or core biopsy and visualization under the microscope to identify abnormal/ cancer cells.  There are several benefits of this procedure such as:

• Biopsy helps in the confirmation of malignancy.
• Direct visualization under the microscope gives valuable information about the tumor (especially in terms of type of cancer as well as staging and grading).
• Investigators can advise treatment options based on the results of biopsy.

Besides these basic tests, your healthcare provider may also advise a number of tests to ascertain the extent of spread of cancer cells (distant metastasis) and local invasion of tumor cells. Some classic tests include:

• Magnetic resonance imaging (MRI)
• Bone scan
• Positron emission tomography (PET) scan
• Ultrasound
• Computerized tomography (CT) scan

If you or someone in your family is at risk of developing prostate cancer, speak to your primary care provider to schedule screening tests for early identification of prostate cancer.

References

1. http://seer.cancer.gov/statfacts/html/prost.html

2. Puech, P., Rouvière, O., Renard-Penna, R., Villers, A., Devos, P., Colombel, M., … & Ouzzane, A. (2013). Prostate cancer diagnosis: multiparametric MR-targeted biopsy with cognitive and transrectal US–MR fusion guidance versus systematic biopsy—prospective multicenter study. Radiology, 268(2), 461-469.

3. Carter, H. B., Albertsen, P. C., Barry, M. J., Etzioni, R., Freedland, S. J., Greene, K. L., … & Penson, D. F. (2013). Early detection of prostate cancer: AUA guideline. The Journal of urology, 190(2), 419-426.