Diagnosing Prostate Cancer

What is a cancer diagnosis?

Diagnosis is not the same as detection. Cancer may be detected when symptoms occur, an abnormality is recognized on digital rectal exam, or you are found to have an elevated blood prostate specific antigen level.  After cancer is detected, it still must be accurately diagnosed.

How is prostate cancer diagnosed?

Prostate cancer once detected must be confirmed with a biopsy and carefully evaluated with a number of other tests in order to determine an accurate diagnosis, stage, and learn additional useful information that can direct treatment.  If laboratory tests or physical examination results suggest that prostate cancer may be present, you will need to have a prostate biopsy. A biopsy is the only way to know for sure whether an individual has cancer. During a biopsy, a needle is used to remove several small pieces of prostate tissue through the rectum. These pieces of prostate tissue are examined under the microscope to determine whether cancer cells are present. If cancer cells are present, an assessment of how aggressive or abnormal the cancer appears is performed. Understanding your pathology report.

What is a cancer stage?

If a prostate cancer diagnosis is confirmed by biopsy, the next step is to determine the stage or extent of spread of the cancer. Stage describes how far the cancer has spread. Each stage of prostate cancer may be treated differently. In order for you to begin evaluating and discussing treatment options with your healthcare team, you need to know the correct stage of your cancer. Determining the stage of the cancer may require a number of procedures, including additional surgery (lymph node evaluation), blood tests, ultrasound, chest x-rays and occasionally, CT/MRI or bone scans.  There are many staging systems, but TNM is the most common. “T” refers to the size of the tumor, “N” to the number of lymph nodes involved, and “M” to metastasis. TNM staging measures the extent of the disease by evaluating these three aspects and assigning a stage, which is usually between 0-4. Generally, the lower the stage, the better the treatment prognosis (outcome).

  • Stage 1 – the cancer cannot be felt during digital rectal examination (DRE) and there is no evidence that cancer has spread outside the prostate.
  • Stage 2 – the cancer can be felt during DRE or there is an elevated prostate-specific antigen (PSA) and there is no evidence that the cancer has spread outside the prostate to other organs.
  • Stage 3 – the cancer has extended through the capsule that encloses the prostate gland and may involve nearby tissues.
  • Stage 4 – the cancer has spread to distant locations in the body, which often includes the bones.

There are many types of tests specifically designed to evaluate cancer:  For more information about diagnostic tests, visit the Testing Center.

How does diagnosis determine treatment?

Overall treatment is determined based on the stage of disease, however other prognostic factors can influence treatment decisions. Higher stage cancers typically receive more aggressive treatments and lower stage disease less aggressive treatment.

Research has indicated that identifying the stage of disease may not be the most accurate technique for determining the cancers aggressiveness. For example, some early stage diseases may recur or progress even after treatment, while some late stage cancers may stay in remission. These findings suggest that there may be factors other than how the cancer looks under a microscope and how far it has spread at the time of diagnosis that may better indicate the likelihood that a given cancer will recur and/or progress.

Human genomics, which is the study of the entire genetic material of humans, has provided invaluable tools for identifying the genetic components of cancers. The mapping of the human genome, which consists of 30,000 to 70,000 genes, has laid the ground work for understanding the role those genes play. Cancer is many different diseases; however, one aspect of all cancers that is similar is damage to the DNA resulting in uncontrolled cell growth. Identifying the genes for each cancer type that are involved in the capacity grow and spread may provide valuable prognostic information.

How is prognosis determined?

The probable course and/or outcome of the cancer is called the prognosis. Identifying factors that indicate a better or worse prognosis will help you and your doctor plan your treatment. There are many factors that help determine your prognosis.  Age, other health conditions and cancer stage effect your prognosis and influence treatment options. The Gleason score and prostate specific antigen blood (PSA) blood level provide additional information that will help individuals make treatment decisions especially for early stage cancers.

Gleason Score:  Cancer that is removed by surgical resection or needle biopsy will be classified according to the Gleason Grading System for prostate cancer. This grading system, on a scale of 2-10, helps physicians predict how rapidly the cancer is likely to spread. Higher Gleason scores are associated with more advanced and more rapidly growing cancers than lower scores.

Prostate-specific antigen blood test:PSA is a protein that is normally secreted and disposed of by the prostate gland. In patients with a known diagnosis of prostate cancer, the PSA level roughly reflects the total amount of cancer. The higher the PSA level, the more likely that the cancer is advanced.

Genomics-OncotypeDX A new genomic test—the Oncotype DX® Prostate Cancer Test—measures the aggressiveness of prostate cancer and may help scores of men choose between immediate treatment or active surveillance.

The Oncotype DX prostate cancer test measures the level of expression of 17 genes across four biological pathways to predict prostate cancer aggressiveness. The test results are reported as a Genomic Prostate Score (GPS) that ranges from 0 to 100 and is combined with other clinical factors to further clarify a man’s risk prior to treatment intervention.  Oncotype DX GPS strongly predicted disease aggressiveness, offering information beyond currently available clinical factors, such as PSA and biopsy Gleason Score, to help physicians and their prostate cancer patients confidently choose the most appropriate treatment based on an individualized risk assessment. What’s more, the test has been validated to guide treatment decisions with the prostate needle biopsy sample—meaning low-risk patients could avoid invasive treatments such as surgery or radiation.

Genomic testing helps individualize treatment. This means that patients with more serious conditions can be identified and offered aggressive and innovative therapies that may prolong their lives, while patients who are diagnosed with a less serious condition may be spared unnecessary treatments.

Next Section: Introduction to Cancer Treatment »