Cancer Grading and Staging
Taber's Medical Encyclopedia
Available on Rxlist.com
http://www.rxlist.com/
2001
Cancer Grading and Staging
The standardized procedure for expressing cancer
cell differentiation, called grading, and the extent of dissemination
of the cancer, called staging.This procedure is very helpful in comparing
the results of various forms of therapy. Cancer is graded on the differentiation
of the tumor cells and the number of mitoses present. These are thought
to be correlated with the ability of the tumor to grow and spread. Some
cancers are graded I to IV, the latter being the most anaplastic and having
the least resemblance to normal tissue. Cancers are staged according to
size, amount of local spread (metastases), and whether blood-borne metastasis
has occurred. There are two major staging systems. The TNM judges the
size of primary tumor (T), evidence of regional extension or nodes (N),
and evidence of metastases (M). Another system classifies cancers as Stage
0 to IV according to the size of the tumor and its spread.
It is not possible to determine the site of the primary malignancy for
some metastatic cancers. The most frequent cell types are adenocarcinoma,
melanoma, lymphoma, sarcoma, and squamous cell carcinoma. Even though
the prognosis is poor for affected patients, their response may be improved
if the cell type is specifically identified.
"Taber's Cyclopedic Medical Dictionary," Copyright © 2001
by F. A. Davis Co., Phil., PA
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