Bladder Cancer (cont.)

Grading of bladder cancer is done by the pathologist by examination of the tumor specimen under a microscope. It is a measure of the extent by which the tumor cells differ in their appearance from normal bladder cells. Greater the distortion of appearance, the higher the grade assigned. High-grade cancers are more aggressive than low-grade ones and have a greater propensity to invade into the bladder wall and spread to other parts of the body.

• Grade 1 cancers have cells that look very much like normal cells. They are called low grade or well differentiated and tend to grow slowly and are not likely to spread.



• Grade 2 cancers have cells that look more abnormal. They are called medium grade or moderately differentiated and may grow or spread more quickly than low grade.



• Grade 3 cancers have cells that look very abnormal. They are called high grade or poorly differentiated and are more quickly growing and more likely to spread.

In 2004, the World Health Organization developed a new grading system for bladder cancer. This system divides bladder cancers into the following groups.

• Urothelial papilloma - noncancerous (benign) tumor



• Papillary urothelial neoplasm of low malignant potential (PUNLMP) - slow growing and unlikely to spread



• Low-grade papillary urothelial carcinoma - slow growing and unlikely to spread



• High-grade papillary urothelial carcinoma - more quickly growing and more likely to spread

Stage and grade of bladder cancer play a very important role not just in deciding the treatment that an individual patient should receive but also in quantifying the chances of success with that treatment. Of note, carcinoma in situ (CIS or Tis, as mentioned in the section on staging) is always high grade.

Source: MedicineNet.com
http://www.medicinenet.com/bladder_cancer/article.htm