Grades of prostate cancer
Grading is a way of classifying prostate cancer cells based on their appearance and behaviour when viewed under a microscope. To find out the grade of a tumour, the biopsy sample is examined under a microscope. A grade is given based on the pattern of growth and how different the prostate cancer tissue looks and behaves compared with normal prostate tissue (differentiation). This can give the healthcare team an idea of how likely the cancer is to grow beyond the prostate.
The most common grading system for prostate cancer is the Gleason classification system. This system is based on the structure of the prostate gland tissue.
- Well-differentiated prostate cancer glands look and behave almost like normal prostate glands. These tumours tend to be less aggressive and slow growing.
- Undifferentiated or poorly differentiated prostate cancer glands look and behave quite differently from normal prostate glands. They look immature and undeveloped. These tumours tend to be more aggressive and to grow more quickly.
Grading plays an important part in planning prostate cancer treatment and can also be used to help estimate the prognosis (future outcome).