PROSTATE CANCER DIAGNOSIS

Accurately diagnosing prostate cancer is crucial in determining which treatment options will be the most effective.

Early Detection and Screening

Most prostate cancers are first found as a result of screening. Two tests commonly used to screen for prostate cancer are:

  • Prostate specific antigen (PSA) level (age-adjusted normal range 4.0 to 6.5)
  • Digital rectal examination (DRE)
    (Roberts et al., 2018; ACS, 2021b)

Prostate Cancer Biopsy

If prostate cancer is suspected based on results of screening or symptoms, the actual diagnosis can only be made by performing a prostate biopsy. A biopsy involves removing about 12 small core samples of the prostate for histological examination. A core biopsy is the main method used.

Biopsies can sometimes miss a cancer, and if it is strongly suspected cancer is present after the biopsy, a repeat biopsy may be considered or other lab tests carried out to confirm it. These tests include:

  • Prostate Health Index (PHI)
  • 4K Score Test
  • PCA3 (Progensa)
  • ExoDxProstate (IntelliScore)
  • TMPRSS2-ERG
  • ConfirmMDx
    (ACS, 2021c)

Determining the Extent of Cancer

To determine if cancer has spread outside of the prostate, imaging tests may be used to provide information about the cancer’s location. Such imaging may include:

  • Bone scan
  • CT scan
  • MRI
  • PET-CT scan
    (ASCO, 2020a)

Grading and Staging

When cancer is found on biopsy, it is graded using the Gleason scoring system, which indicates how quickly a cancer is growing. The lower the score, the healthier the cells appear. The lowest score for a low-grade cancer is 6. A score of 7 is medium grade, and 8–10 are high grade cancers.

Staging indicates how advanced the cancer is. The most common method is the TNM staging system. For instance:

  • T (tumor) indicates extent of primary tumor.
  • N9 (node) indicates spread to lymph nodes near the bladder.
  • M9 (metastasis) indicates spread to other lymph nodes and organs.
    (ASCO, 2021a)
T1, T2, T3 stage, prostate cancer

Stages T1–3 prostate cancer.
(Source: Cancer Research UK / Wikimedia Commons.)