Ask the Pathologist: Dr. Leo Niemeier

Dr. Leo Niemeier is a pathologist at OhioHealth
Dr. Leo Niemeier is a pathologist at OhioHealth

As a survivor you probably now know more medical terms than before your diagnosis. From your diagnosis through recovery, you have a highly trained team that you work with to map out your treatment but do you know what part a pathologist plays on that team?

A pathologist is a physician who looks at the tissue under a microscope and determines whether or not the tissue contains cancer. The pathologist prepares a report of the findings, including the diagnosis, and sends it to the ordering physician (either a surgeon or oncologist).

In February’s Survivor Newsletter* we offered survivors the opportunity to ask questions  regarding biopsy, diagnosis and prognosis to Dr. Leo Niemeier, a pathologist at OhioHealth.

Below are some questions we received and Dr. Niemeier’s response.

*Sign up for our survivor-only newsletter here.

Q1: My pathology report for invasive ductal carcinoma reported a mix of mucinous and non-mucinous cancer cells. I guess if one is bad and one is better, I should still be worried because I had both?

A1: Not necessarily. The presence of mucinous and non-mucinous components of an invasive ductal carcinoma simply means that the tumor has expressed two different patterns of growth. The presence or absence of mucin alone is not solely indicative of the tumor’s biology. A better indicator, found on your pathology report, is the overall grade of your tumor. Grade 1 tumors are generally less aggressive than grade 2 tumors. Grade 3 tumors tend to be the most aggressive types.

Q2: Does invasive ductal carcinoma LOOK different than other breast cancers, say triple negative OR are they named what they are because of how the cells react (split and multiply)?

A2: Generally speaking, there are two main types of invasive breast cancers, invasive ductal carcinomas and invasive lobular carcinomas. And yes, they can look very different when we examine them under a microscope. Sometimes these two types of cancers can look similar, so as pathologists, there are other tests that we can do to tell them apart. A triple negative cancer is named that because of its breast predictive factor profile (i.e ER-estrogen receptor, PR-progesterone receptor, and HER2/neu) being negative for all three tests. As pathologists, we perform the breast predictive factor testing in our laboratory to help categorize the various types of invasive breast cancers.

Q3: Why did my initial needle biopsy report show that my cancer was ER+,PR+,Her2- but after my lumpectomy I had an oncotype test run and it came back ER-,PR+,Her2-? I questioned the oncotype lab and they said it wasn’t a typo. Then I called my breast health nurse at riverside who contacted riverside pathology department. The head of pathology looked up my chart and said as far as ER positives go, I had tested about as positive as could be. Can this be explained?

A3: Yes it can be explained. Your question highlights a very important concept that occasionally happens. The breast predictive factors testing that the majority of pathology laboratories across the country perform is by a method called immunohistochemistry or IHC for short. Immunohistochemistry is a nationally accepted method for breast predictive factor testing in breast cancer. Once we perform these tests, we interpret them based on nationally accepted criteria from the collaboration of the American Society of Clinical Oncology and the College of American Pathologists.

A company called Genomic Health, based in California, offers the Oncotype Dx test. This test quantifies the likelihood of cancer recurrence in women with early-stage hormone estrogen receptor (ER) positive only breast cancer and assesses the likely benefit from certain types of chemotherapy. Their test utilizes a testing method, different from IHC, known as RT-PCR (Reverse transcription polymerase chain reaction). Their test uses RT-PCR to determine the expression profile of a 21-gene panel within a breast cancer to determine a Recurrence Score. In addition to a recurrence score, they also provide information on ER, PR, and HER2/neu results from their RT-PCR process. Overall, there is a very high percentage of concordant results from both of these tests (i.e. positive or negative results from both tests).

So, basically what we have identified here with your question is that there are two different methods or tests to determine the ER status of breast cancer and two different criteria of what constitutes a “positive” or “negative” result. This would explain why one test called your cancer ER+ and the other ER-. This topic is highly debated on both sides as to which test is superior. Thus far, there is not enough evidence-based published data to indicate which is most accurate.

Q4: What kind of information does the pathologist give my medical oncologist about my diagnosis and how does the oncologist use that information?

A4: A pathologist generates a final report about your breast cancer based on a combination of a gross and microscopic pathologic examination. The final pathology report includes very detailed information about your breast cancer including the type of cancer, size, grade, margin status, lymph node status, presence or absence of vascular invasion, breast predictive factor status, and the pathological stage. The medical oncologist uses all of this information to develop the best treatment plan for your particular type of breast cancer.