Grading bladder cancer

Grading describes how the cancer cells look compared to normal, healthy 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), including how the cancer might respond to treatment and the chance that the cancer will come back (recur).

To find out the grade of bladder cancer, a pathologist looks at a tissue sample from the tumour under a microscope. They look at how different the cells look from normal cells (called differentiation) and other features of the tumour such as the size and shape of the cells and how the cells are arranged. They can usually tell how fast a tumour is growing by looking at how many cells are dividing.

The pathologist may give bladder cancer a grade from 1 to 3. A lower number means the cancer is a lower grade.

Low-grade cancers have cancer cells that are well differentiated. The cells are abnormal but look and are arranged a lot like normal cells. Lower-grade cancers tend to grow slowly and are less likely to spread.

High-grade cancers have cancer cells that are poorly differentiated or undifferentiated. The cells don’t look like normal cells and are arranged very differently. High-grade cancers tend to grow more quickly and are more likely to spread than low-grade cancers. They are also more likely to come back after treatment. Almost all invasive bladder cancers are high grade when diagnosed.