Tumor Characteristics

Breast cancers are graded on a 1 to 3 scale

Grade 1: The cells look fairly normal (well differentiated)

Grade 2: The cells are somewhat abnormal (moderately differentiated)

Grade 3: The cells have lost their proper structure and function (poorly differentiated)

A pathologist determines the grade by looking at the size and shape of the cell and its nucleus, and by counting how many cells are in the process of dividing. The higher the grade the faster it is growing and the more likely it is to spread.

The goal of breast cancer research is to learn about the characteristicsof cells in individual tumors. Researchers can identify genes associated with breast cancer and measure their activity in tissue samples, thus giving them additional information such as the likelihood of recurrence. These tests, known as genetic profiling or gene-expression profiling, have so far only been used only for a minority of breast cancers.

Some researchers have proposed a new way to classify breast cancers based on molecular features rather than on the cancer's appearance under the microscope.

These types include:

Luminal A and luminal B: The genetic activity of these cancers is similar to that of normal lumen cells - those that line the breast ducts and glands. Luminal cancers are estrogen receptor positive and usually grow slowly.

HER2/neu: Human Epidermal Growth Factor Receptor 2, is a protein that appears on the surface of some breast cancer cells. It is important for cell growth and survival. HER2/neu-positive breast cancers have a lot of HER2/neu protein and HER2/neu-negative breast cancers have little or no HER2/neu protein.

About 15 to 20 percent of all breast cancers are HER2/neu-positive and tend to be more aggressive than HER2/neu-negative cancers. HER2/neu-positive cancers are often estrogen receptor-negative and have a poor tumor grade, all of which lead to poorer prognosis.

Basal: Basal breast cancers have normal levels of HER2/neu and lack estrogen and progesterone receptors. This type of cancer is known as "tripple negative" and grows rapidly.

Tumor markers are substances found in the blood, urine, stool, other bodily fluids, or tissues of some patients with cancer. Tumor markers may be used to help diagnose cancer, predict a patient’s response to certain cancer therapies, check a patient’s response to treatment, or determine whether cancer has returned. More than 20 tumor markers are currently in use.

Tumor markers are substances that are produced by cancer cells or by other cells of the body in response to cancer or certain benign (noncancerous) conditions. Most tumor markers are made by normal cells as well as by cancer cells; however, they are produced at much higher levels in cancerous conditions. These substances can be found in the blood, urine, stool, tumor tissue, or other tissues or bodily fluids of some patients with cancer. Most tumor markers are proteins. However, more recently, patterns of gene expression and changes to DNA have also begun to be used as tumor markers. Markers of the latter type are assessed in tumor tissue specifically.

Thus far, more than 20 different tumor markers have been characterized and are in clinical use. Some are associated with only one type of cancer, whereas others are associated with two or more cancer types. There is no “universal” tumor marker that can detect any type of cancer.

There are some limitations to the use of tumor markers. Sometimes, noncancerous conditions can cause the levels of certain tumor markers to increase. In addition, not everyone with a particular type of cancer will have a higher level of a tumor marker associated with that cancer. Moreover, tumor markers have not been identified for every type of cancer.

Karen Moody ...© All rights reserved