Invasive Ductal Carcinoma (IDC)

The following information is a good summary of tumor grade, taken from http://www.cancerfacts.com/DefaultSecure.asp "Tumor grade (G) is an evaluation of how abnormal a cancer cell is compared to the normal cells from which it arises. This evaluation is called the "histologic tumor grade" and is done by the pathologist when examining the biopsy specimen. Histology is the study of the microscopic structure of the cells, which helps to predict how the cancer will behave. An objective score is given to each of three structural features of the tumor. A score of 1 (the most favorable) to 3 (the least favorable) is given for each feature.

The total score determines the tumor grade. This system describes the cell in terms of how well the cancer cell resembles the normal cell from which it arises. If the cancer cell looks very much like a normal breast cell, then it is called "well-differentiated". If the cancer cell poorly resembles a normal breast cell or not at all, then it is called "poorly differentiated or undifferentiated".

GX: grade cannot be assessed, undetermined grade
G1: well differentiated (low grade) This is the most favorable grade and reflects a total score of 3-5
G2: moderately differentiated (intermediate grade) This reflects a score of 6-7
G3: poorly differentiated (high grade) This is the least favorable grade, with a score of 8-9

Different systems are used to categorize the histologic (referring to tissue) tumor grade. The NCCN currently recommends using The Nottingham combined system for grading tumors. Another classification system is the Bloom-Richardson Score. The systems are similar: the higher the score, the less favorable the tumor.

The tumor grade can influence treatment decisions, especially if additional treatment such as chemotherapy or hormone therapy is needed after surgery."

It is important to note the difference between tumor GRADE, which as described above comments on the individual cancer cell, and tumor STAGE, which refers to the size of the main tumor and the presence or absence of lymph node or distant (to other areas in the body) metastases. It is possible to have a "low grade / well-differentiated" tumor that is diagnosed at an advanced stage, and it is also possible to have a "high grade / poorly differentiated" tumor that is early-stage.

It used to be thought that stage of disease (size of tumor, presence or absence of lymph node metastases) was the most important prognostic indicator. We are learning more about how the biologic behavior (grade is just one component of the behavior of a tumor) may be more important in many cases than the stage at diagnosis. The following information is a good summary of tumor grade, taken from http://www.cancerfacts.com/DefaultSecure.asp "Tumor grade (G) is an evaluation of how abnormal a cancer cell is compared to the normal cells from which it arises. This evaluation is called the "histologic tumor grade" and is done by the pathologist when examining the biopsy specimen. Histology is the study of the microscopic structure of the cells, which helps to predict how the cancer will behave. An objective score is given to each of three structural features of the tumor. A score of 1 (the most favorable) to 3 (the least favorable) is given for each feature.

The total score determines the tumor grade. This system describes the cell in terms of how well the cancer cell resembles the normal cell from which it arises. If the cancer cell looks very much like a normal breast cell, then it is called "well-differentiated". If the cancer cell poorly resembles a normal breast cell or not at all, then it is called "poorly differentiated or undifferentiated".

GX: grade cannot be assessed, undetermined grade
G1: well differentiated (low grade) This is the most favorable grade and reflects a total score of 3-5
G2: moderately differentiated (intermediate grade) This reflects a score of 6-7
G3: poorly differentiated (high grade) This is the least favorable grade, with a score of 8-9

Different systems are used to categorize the histologic (referring to tissue) tumor grade. The NCCN currently recommends using The Nottingham combined system for grading tumors. Another classification system is the Bloom-Richardson Score. The systems are similar: the higher the score, the less favorable the tumor.

The tumor grade can influence treatment decisions, especially if additional treatment such as chemotherapy or hormone therapy is needed after surgery."

It is important to note the difference between tumor GRADE, which as described above comments on the individual cancer cell, and tumor STAGE, which refers to the size of the main tumor and the presence or absence of lymph node or distant (to other areas in the body) metastases. It is possible to have a "low grade / well-differentiated" tumor that is diagnosed at an advanced stage, and it is also possible to have a "high grade / poorly differentiated" tumor that is early-stage.

It used to be thought that stage of disease (size of tumor, presence or absence of lymph node metastases) was the most important prognostic indicator. We are learning more about how the biologic behavior (grade is just one component of the behavior of a tumor) may be more important in many cases than the stage at diagnosis.