Grade vs Stage

['lizbeth]

The grade is included in the pathology report, but it isn't in the current staging of invasive breast cancer.

This is a easy to understand explanation which I borrowed from Susan G. Komen's website.

Tumor grade

For invasive breast cancers, the pathologist notes the shape of the cancer cells and assigns a histologic grade, using either a number system or words. Tumor grade describes the structure of the cells and is different from tumor stage. In general, the more the cancer cells look like normal breast cells, the lower the grade and the better the prognosis.
The most common grading system in current clinical practice is the Nottingham system:

Grade 1:

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Well-differentiated (cells look most similar to normal and are not growing rapidly)

Grade 2

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Moderately-differentiated (cells look somewhat different than normal)

Grade 3

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Poorly-differentiated (cells look very abnormal, and may be growing and spreading rapidly)

Nuclear grade

The nuclear grade describes how closely the nuclei of cancer cells look like the nuclei of normal breast cells. In general, the higher the grade, the more abnormal the nuclei are and the more aggressive the tumor cells tend to be. The nuclear grade is a part of overall tumor grade.
Learn more about histologic grading and prognosis.