If your doctor suspects you have breast cancer, you’ll likely have a biopsy to determine your exact diagnosis. During that biopsy, cells, tissue or sometimes the entire lump will be removed from the breast and sent to a laboratory for testing. This testing is conducted by a pathologist and typically involves examining cells under a microscope to determine their specific characteristics.

Once the testing is complete, the pathologist will generate a report that includes his or her findings and the diagnosis. This report is called a pathology, or biopsy, report. The report may also include results from any other screenings or tests you’ve had such as mammograms, MRIs or ultrasounds. The information in this report forms the basis of your diagnosis, and it will help guide the many treatment decisions you and your doctor need to make next.

The National Breast Cancer Foundation reports that most pathology reports take one to two weeks to complete. Before you have the biopsy, ask your doctor how the results will be communicated to you. Waiting really can be the hardest part, and knowing when you can expect to hear back from your doctor about your health status can help alleviate some of the anxiety and fear that can develop around this pensive time.

Breastcancer.org, which has created a 45-page guide outlining what’s in most pathology reports, explains that depending on the doctor and the facility, you may need to receive your testing results in person regardless of whether they’re good or bad. Some doctors may offer the information in other ways, but it’s best to discuss with your doctor ahead of time what to expect.

[See: Breast Pain? Stop Worrying About Cancer.]

Most pathology reports will include the following pieces of information about the cells that were examined.

Cell Type

This is the designation of whether the cells were cancerous or not, and the results will be listed as either malignant, which means cancerous, or benign, which means not cancerous. If your report states that the cells were benign, you have not been diagnosed with cancer. According to the Johns Hopkins Breast Center, about 80 percent of all biopsies turn out to be benign. If, however, your cell type is listed as malignant, then cancer was detected in the tissue culled during the biopsy.

Type of Breast Cancer

If the cells are deemed cancerous, you’ll receive information about the type of breast cancer you’ve got. Breast cancer is broadly divided into non-invasive — cancers that stay within the milk ducts or lobules — or invasive — cancers that have moved into other tissues.

Grade

Your pathologist will also include information about the grade of the tumor cells. The National Cancer Institute maintains a tumor-grading scale that describes “how abnormal the tumor cells and the tumor tissue look under a microscope.” If the cells are similar to normal breast cells, the tumor is “well-differentiated,” and the cancer will grow and spread more slowly than “undifferentiated” or “poorly differentiated” cells, which look abnormal and “may lack normal tissue structures.”

This grade analysis is not the same as staging the cancer. As the NCI reports, “cancer stage refers to the size and/or extent (reach) of the original (primary) tumor and whether or not cancer cells have spread in the body.” Cancer staging takes into account the location and size of the tumor and whether cancerous cells have spread to nearby lymph nodes and often requires more testing than just a biopsy. Grading, on the other hand, looks at the cells removed from the tumor and determines how they are likely to grow. Grade 1 tumors are the least aggressive and grade 4 are the fastest growing. You may also see a listing of grade X on your pathology report, which means the grade couldn’t be assessed.

[See: Which Medical Screenings Should You Have in 2017?]

The NCI reports that most breast cancer doctors use the “Nottingham grading system (also called the Elston-Ellis modification of the Scarff-Bloom-Richardson grading system),” that grades tumors on tubule formation, nuclear grade and mitotic rate. Tubule formation refers to how much of the tumor tissue has normal milk duct structures while nuclear grade evaluates the size and shape of the nucleus, or command center, of the cells. Mitotic rate refers to how fast cells are growing and dividing. All three characteristics are added up in a total score. A total score of 3 to 5 results in a G1 grading (low grade or well differentiated). A total score of 6 to 7 is a G2 rating — intermediate grade or moderately differentiated. And a total score of 8 to 9 is G3 or high grade or poorly differentiated. A lower grade generally indicates a better prognosis.

Hormone Receptor Status

This information refers to how the tumor cells are fed. A vast majority of breast cancers are hormonally driven, meaning that the tumor cells use hormones the body makes naturally to grow. Hormone receptors are proteins in or on the cancer cells that receive hormones the cell can use to grow.

According to Breastcancer.org, there are five different hormone receptor designations you could receive:

— ER+ indicates your cancer is estrogen-receptor positive. About 80 percent of breast cancers fall in this category.

— ER+/PR+ means both estrogen and progesterone receptors were detected in your sample. About 65 percent of breast cancers are ER+/PR+.

— ER+/PR- means that only estrogen is feeding the cancer. About 13 percent of breast cancers are ER+/PR-.

— ER-/PR+ indicates that progesterone is supporting the growth of the cancer. About 2 percent of breast cancers are classified this way.

— ER-/PR- breast cancers do not have hormone receptors and account for about 25 percent of all breast cancer cases.

Your hormone receptor status is important to determining the next steps in treatment. If your cancer is hormone positive, your treatment plan will likely include hormone therapies such as tamoxifen or aromatase inhibitors. The Susan G. Komen organization reports that “hormone therapy prevents the cancer cells from getting the hormones they need to grow and may stop tumor growth.”

HER2 Status

According to the American Cancer Society, HER2, which stands for human epidermal growth factor receptor 2 and may also be listed as HER2/neu, “is a growth-promoting protein on the outside of all breast cells.” Breast cancer cells with higher-than-normal levels of HER2 will be listed as HER2-positive and these cells tend to grow and spread faster than other breast cancers.

[See: A Tour of Mammographic Screenings During Your Life.]

Additional Details

Your pathologist will also likely include a description of what was observed under the microscope along with information about the size, weight, color and texture of the sample, as well as the location and shape of the tumor from where the sample was sourced. If the entire tumor was removed, your pathologist will report on the margin — a border of healthy cells that were removed along with the tumor — to help determine whether all of the cancerous cells were removed or whether additional surgery may be indicated.

If any lymph nodes were removed or biopsied, information about whether cancer was detected there will appear on your pathology report, and this can be used to help stage the cancer, or determine how advanced it is. Your report may also include information about any genetic mutations that may help your doctor better treat you. Your pathologist may include other information relevant to your specific situation and diagnosis.

When your report arrives, discuss it with your doctor. You may also want to consider getting a second opinion, especially if you’ve been diagnosed with a rare form of breast cancer. There’s always a chance of false negatives or false positives, so getting a second expert to review your case is generally a good idea.

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How Do I Read My Breast Cancer Biopsy Report? originally appeared on usnews.com