Types of Prostate Cancer According to Stages and Grades

Prostate Cancer Classification

Different types of prostate cancer are classified according to the parameters of stage and grade. In terms of stages, there are broadly two categories of prostate cancer, which are clinical stage and pathological stage. The clinical stage of prostate cancer is determined on the basis of preliminary information available upon examinations such as the digital imaging of the rectum. But this stage does not take the PSA test or the Gleason score into account.

The pathological stage of prostate cancer is evaluated once the lymph nodes or the prostate have been surgically removed. The doctor is then in a better position to judge the spread of tumor to surrounding tissue and other areas, and make a further prognosis. The most common way to classify prostate cancer stages is by using the TNM system, where T is for tumor, N for lymph node, and M for metastasis. T1 and T2 are early stages, T3 and T4 are advanced stages, N denotes metastasis to lymph nodes, and M indicates distant metastasis.

Types of Prostate Cancer by Stages

Stage I prostate cancer is localized to the prostate. It is microscopic in size and cannot be detected by a digital imaging of the rectal area. It is not noticeable even on the digital imaging of the prostate. In Stage II, the tumor becomes large and noticeable through digital rectal examination or a digital imaging of the prostate. However, at this stage, the tumor is confined only to the prostate.

Prostate cancer is classified as Stage III type when the tumor has extended beyond the prostate. However, at this stage the metastasis is only marginal and only tissue surrounding the prostate may be affected by the cancer. Stage IV is the stage of distant metastasis when the tumor has spread to other parts of the body. The organs commonly affected by prostate metastasis include the lungs, liver, lymph nodes and bones. Correct identification of the stage of cancer is very important to decide the best treatment approach.

Prostate Cancer Types by Grading

Just like staging classification, grading levels are also determined in the cases of prostate cancer. Grading method is performed once a sample of the affected tissue has been removed for biopsy. The tissue sample is analyzed in the lab by a pathologist who will assign the grading for the prostate cancer if it is detected. Grading is determined by the appearance and pattern of the cancerous cells. The most common grading scale used by pathologists in this cancer is the Gleason score, which assigns grades from 1 to 5.

Grade 1 prostate cancer is assigned if the cancer cells in the prostate tissue appear very similar to the healthy cells. Grades 2, 3 and 4 are assigned when some of the malignant cells appear like healthy prostate cells, while some others look abnormal. Grade 5 prostate cancer is assigned if almost all the cells in the prostate appear to be abnormal, and are spread in an irregular manner throughout the prostate. The higher the Gleason score, the more aggressive the prostate cancer is likely to be.

References

Prostate Cancer Treatment Guide: https://www.prostate-cancer.com/prostate-cancer-treatment-overview/overview-staging.html

Web MD: https://www.webmd.com/prostate-cancer/guide/prostate-cancer-grading-prostate-cancer