Prostate Cancer Staging

The results of a prostate biopsy are often confusing: “A stage two adenocarcinoma with a Gleason score of three.” What’s that supposed to mean? Before you get your prostate biopsy results, you might want to learn a little about the grading and staging terminology: nothing too complex, just enough to be prepared.

Adenocarcinoma

The vast majority (95 percent) of prostate cancers are adenocarcinomas. An adenocarcinoma is a malignant cancer that starts in the cells lining the ducts and tubes of a glandular organ. Prostate adenocarcinomas are the second most common malignant cell growth found in men over 65. Only melanoma has a higher rate of occurrence.

Prostatic Intraepithelial Neoplasia (PIN)

 Sometime a histology report indicates that the biopsy produced “atypical” results, or evidence of prostatic intraepithelial neoplasia (PIN). PIN is not cancerous, but high-grade PIN is associated with an increased risk of prostate tumors, and needs to be routinely monitored. Neoplasia is simply the abnormal growth of cells.

Defining Histology

Histology is the scientific branch that examines the structure of tissues at a cellular level.

Reading a Gleason Score

Most North American prostate biopsy reports assign a Gleason score to malignant growths. Other scoring systems exist throughout the world, but the Gleason is one of the most common systems. Essentially, the tumor is given a grade according to the structure of the abnormal cells. The lower the grade, the closer the malignant cells’ appearance and function to normal cells. Cell structure is assigned a grade between one and five.

Grade One: The cells closely resemble normal prostate cells; the malignant cells are pale-colored, and grow close together.

Grade Two: The tissue sample resembles grade one, but the abnormal growth is less compact; cells may have invaded surrounding muscle tissue.

Grade Three: Abnormal tissue color is darker, and cells have different shapes; more invasion of muscular tissue than grade two.

Grade Four: Cell construction becomes increasingly abnormal.

Grade Five: Malignant growth shows a wide variety of patterns at the cellular level.

Two samples of abnormal tissue patterns are usually analyzed, and their individual score is added together. The lowest possible Gleason score is two (both samples are grade one), and the highest score is ten. Higher Gleason scores indicate less positive prognosis, but not always. Some men with high scores respond well to treatment.

Cancer Staging

Cancer staging is a way of summing up the information from biopsies, Gleason scores, radionuclide bone scan, ProstaScintTM scans and other diagnostic tools. Cancer scoring ranges from stage one to stage four, with the prognosis becoming progressively worse at each stage.

Stage One: Malignant cells are confined to the prostate; they have not spread to the lymph nodes or other organs; Gleason scores are between two to four, and less than five percent of the prostate is composed of tumor growth.

Stage Two: Gleason scores are five or higher, or over five percent of the gland shows abnormal growth; the cancer is still restricted to the prostate.

Stage Three: Malignant cells have spread to the seminal vesicles, but not to the lymph nodes or other organs.

Stage Four: The lymph nodes, pelvic tissue or more distant organs are affected.

Resources

American Cancer Society. (2003). How is prostate cancer staged? Retrieved January 29, 2003, from www.cancer.org/docroot/cri/content/cri_2_4_3x_how_is_
prostate_c ancer_staged_36.asp?sitearea=cri.

Virginia Urology. (nd). The grading of prostate cancer. Retrieved January 29, 2003, from www.uro.com/gleason.htm.