Grading penile cancer
The grade is a description of how the cancer cells look compared to normal cells. To find out the grade of penile cancer, the pathologist looks at a tissue sample from the penis under a microscope. The pathologist gives penile cancer a grade from 1 to 4. A lower number means the cancer is a lower grade.
How different the cancer cells are is described as differentiation.
Low grade means that the cancer cells are well differentiated. They look almost like normal cells. Lower grade cancer cells tend to be slow growing and are less likely to spread.
High grade means that the cancer cells are poorly differentiated or undifferentiated. They look less normal, or more abnormal. Higher grade cancer cells tend to grow more quickly and are more likely to spread than low-grade cancer cells.
Knowing the grade gives your healthcare team an idea of how quickly the cancer may be growing and how likely it is to spread. This helps them plan your treatment. The grade can also help the healthcare team predict future outcomes (your prognosis) and how the cancer might respond to treatment.
American Joint Committee on Cancer. AJCC Cancer Staging Handbook. 7th ed. Chicago: Springer; 2010.
American Society of Clinical Oncology. Penile Cancer. 2014: http://www.cancer.net/cancer-types/penile-cancer.