How Do I Read My Breast Cancer Biopsy Report?

A breast biopsy helps your doctor understand whether that lump is cancerous.

Virtually every medical procedure generates a report of some sort or another. And this holds true if you’ve recently had a biopsy of the breast because you found a lump or your radiologist noticed a possible tumor on a recent mammogram image.

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 and whether or not you have breast cancer.

What is a biopsy report?

Usually within a few days to a week or more after the examination, you’ll receive a biopsy report, also called a pathology report, that contains all kinds of information about what was discovered about the sample of tissue collected during the procedure.

The report may also include results from any other screenings or tests you’ve had such as mammograms, MRIs or ultrasounds.

“A pathology report is used to help guide and manage a patient’s treatment and care if they receive a cancer diagnosis,” says Dr. Meghan Flanagan, a breast cancer surgical oncologist with Seattle Cancer Care Alliance and assistant professor of surgery at the University of Washington.

“Your doctor should begin by sharing the whole pathology report with you,” and explain everything that’s included there, says Dr. Courtney Vito, a board-certified breast surgeon at Crosson Cancer Institute at Providence St. Jude Medical Center in Orange County, California. “Your biopsy report is a wealth of information.”

But, it may need some interpretation.

“Reading and interpreting the information in a report can be confusing and overwhelming without the help of your doctor,” Flanagan says. When you’re first diagnosed is “a critical time for patients to advocate for their health. They should make sure that they are comfortable with their doctor and that they understand the report and how it may affect their treatment plan.”

You can expect to find the following five key pieces of information on your biopsy report:

1. Cell type, or whether cancer has been detected

This is the designation of whether the cells were cancerous or not, and the results will be listed as either:

— Malignant — cancerous.

Benign — not cancerous.

If your report states that the cells were benign, you have not been diagnosed with cancer. According to information from the breast center at Johns Hopkins Hospital, about 80% of all biopsies turn out to be benign. If, however, your cell type is listed as malignant, then cancer was detected in the tissue collected during the biopsy.

However, even if the lesion is determined to be non-cancerous, this doesn’t always mean you don’t need to seek further treatment. “Some of these lesions are still considered high-risk and may need therapy,” Vito says.

2. Type of breast cancer

If the cells are deemed cancerous, you’ll receive information about the type of breast cancer you’ve got. “There are many different types of breast cancer and their treatments vary significantly,” Vito says.

Breast cancer is broadly divided into two categories:

— Non-invasive — cancers that stay within the milk ducts or lobules.

— Invasive — cancers that have moved into other tissues.

“Most breast cancers are invasive ductal cancers,” or IDC, Vito says. These cancers start in the milk ducts. They account for about 80% of all breast cancer diagnoses.

3. Grade and aggressiveness

The report will also include information about the cancer’s grade, “which tells you how abnormal the cells in your cancer look compared to normal breast cells. The higher the grade, generally the more aggressive the cancer can be,” Vito says.

Grading 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.

This grade analysis is not the same as staging the cancer. Determining a cancer’s stage means ascertaining whether it has begun spreading to nearby structures such as lymph nodes — structures of the immune system that often are the first place a cancer spreads. Cancer staging takes into account the location and size of the tumor and often requires more testing than just a biopsy.

Your biopsy report may also include information about the cells’ Ki-67 percentage. “This gives us an idea of how quickly the cells are dividing within your cancer and therefore how fast it may be growing,” Vito says. “Numbers greater than 20% usually give us an idea that this is a more aggressive cancer and may require more aggressive therapy.”

4. Hormone receptor and HER2 status

This information refers to how the tumor cells are fed. A vast majority of breast cancers — more than 80% according to statistics from the American Cancer Society — are hormone receptor–positive. This means that the tumor cells use hormones the body makes naturally to grow. Hormone receptors are proteins in or on the cancer cells where hormones can attach and be used by the cell to grow.

“The different combinations of these receptors give your medical team an idea about how best to treat you,” Vito says.

Hormone receptor designations you could receive include:

ER+/PR+ means both estrogen and progesterone receptors were detected in your sample and the cancer cells use both of these hormones to grow.

ER+/PR- means that only estrogen is feeding the cancer but progesterone is not.

ER-/PR+ indicates that progesterone is supporting the growth of the cancer.

ER-/PR- indicates a breast cancer that does not have hormone receptors. These account for about 25% of all breast cancer cases. Cancers that lack estrogen and progesterone receptors are more likely to require chemotherapy, Vito says.

HER2, which stands for human epidermal growth factor receptor 2 and may also be listed as HER2/neu, is a growth-promoting protein found 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.

Cancers that are HER2 positive “almost always require chemotherapy,” Vito says. Tumor markers that are estrogen and progesterone receptor positive but HER2/neu negative may not in many cases require chemotherapy.

Your HER2 and hormone receptor status is important to determining the next steps in breast cancer treatment. If your cancer is hormone positive, your treatment plan will likely include hormone therapies such as tamoxifen or aromatase inhibitors

5. Other details

Most reports include a “Final Diagnosis” section, which Vito says contains the most important information. “This will give you the name of your condition, which is the most important first step in formulating a treatment plan,” Vito says.

Your pathologist will also likely include a description of what was observed under the microscope, along with information about the source location, size, weight, shape, color and texture of the sample. If the entire lump 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 needed.

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 can help your doctor better treat the cancer. Your pathologist may include other information relevant to your specific situation and diagnosis.

How the diagnosis is made

Three tests must be completed before a final diagnosis can be made, Vito says. “The first test is the pathologist giving a benign diagnosis after looking at the cells under the microscope.”

Then, the radiologist looks at the results of that first test conducted by the pathologist and “decides if the pathologic findings can explain the imaging abnormality,” or the mass that’s been noticed on the mammography, ultrasound or MRI images. “If the radiologist agrees that, ‘yes, what the pathologist is seeing under the microscope explains what I’m seeing on either the mammogram, ultrasound or breast MRI,’ then we have concordance,” meaning that they are in agreement.

But “if the radiologist doesn’t think that the pathologist’s findings explain the imaging abnormality, then we have discordance,” Vito says. “We must ask whether the correct area was biopsied in the breast because occasionally, even with the best team, biopsies can be mis-targeted because the breast is so mobile.” The biopsy may need to be repeated, or a different type of biopsy may need to be conducted before a firm diagnosis can be made.

The third step is achieving so-called clinical concordance. “This is when your doctor, who knows your breast history and has examined you, looks at both the pathologic and radiologic findings to see if they agree with your clinical picture,” Vito says.

Depending on the situation, you may need additional testing or procedures before clinical concordance can be achieved.

Questions to ask your doctor

Once you’ve got your report, review it carefully and make a list of questions to ask your doctor. “Don’t be afraid to ask a lot of questions,” Vito says. Your doctor is an expert who can help you understand all aspects of the diagnosis and how that may translate into a treatment plan moving forward.

“Understandably, having a biopsy can create anxiety for many patients, but understanding the biopsy results is key to determining the next steps,” Flanagan says. She also says you should “never be afraid to ask questions” and recommends making sure you discuss the following topics with your doctor:

— What type of cancer is it?

— How big is the tumor and where is it located?

— What stage is the cancer?

— Are additional tests needed?

— What are the next steps?

Flanagan adds that “genetic testing can influence treatment plans, and detection of specific genetic mutations can help clinicians develop targeted treatment plans based on those genetic mutations. Not all patients require genetic testing, but it’s important to review your family history with your provider to determine if it’s recommended.”

And while it might be tempting to head straight to the computer at the first sign of confusion, Vito warns that you may want to think twice before searching unfamiliar terms on the internet. “Your own doctor should be one of the most important sources of information.”

Don’t panic.

Some of the best news your biopsy report may contain is an indication that the mass is benign, or not cancerous. This happens frequently. On the other hand, your report may include some frightening words such as “atypical” or “abnormal,” Vito notes. Other times, even when the word carcinoma, which usually means cancer, appears, it could be referring to a benign condition called lobular carcinoma in situ and may not be as scary as it first sounds.

In all cases, 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.

“It’s very important to read over your pathology report with your doctor to make sure that you’re understanding well” the information that’s included and what, if any, steps you may need to take next, Vito says.

“Reading and understanding your breast cancer biopsy report is the first step towards empowering yourself with knowledge so that you can advocate for yourself and ensure that you’re pursuing the best possible care that meets your own needs and goals of treatment,” she adds. “Knowledge, in this case, truly is power.”

5 key pieces of information on your breast biopsy report:

1. Cell type, or whether cancer has been detected.

2. Type of breast cancer.

3. Grade and aggressiveness.

4. Hormone receptor and HER2 status.

5. Other details, such as size and shape.

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

Update 01/05/22: This story was previously published at an earlier date and has been updated with new information.

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