How do I interpret my pathology report?
You will receive at least 2 different pathology reports during your cancer experience – one at diagnosis which will describe the biopsies and a full final report after surgery on the removed breast(s) and lymph nodes. Breast cancer pathology reports are one of the more complex pathology reports and can seem quite overwhelming at first glance. Ask your doctor or nurse to explain any terms you are unfamiliar with, and what that means for your treatment or prognosis. Both types of reports will tell you what histological type of breast cancer you have. Breast cancers are almost all epithelial cancers that arise from glandular tissue. Breasts have lobules, which make the milk and ducts which carry the milk to the nipples. Depending on which type of cells the cancer most resembles, you get a designation of “ductal carcinoma” or “lobular carcinoma” or mixed. There are also a few very rare subtypes that IBC can resemble. About 85% of IBCs are ductal carcinomas. The subtype does not affect your treatment, but knowing your subtype gives some additional information about potential biological differences. Lobular carcinomas have some unusual metastatic spreading patterns, such as to the GI organs and gynecological system, but overall the rate of metastasis is not different between ductal and lobular cancers matched stage for stage.
When you are diagnosed, you will be most interested in knowing the aggressiveness of the disease and your ER, PR and HER2 status. Aggressiveness is semi-quantified by a grade, usually 2 or 3 (with 3 being high grade) as well as comments on the punch biopsy sample mentioning tumor cells that have invaded local lymphatic vessels or blood vessels (known as “lymphovascular invasion”). If you see the word “pleomorphic” that means different – ie pleomorphic nuclei means that the tumor cells have nuclei that look different. This is a feature of a high grade cancer. In the US, ER and PR are usually reported on 1-100 scale representing the percentage of positive cells for these proteins. Any positive number is taken as a sign that your cancer may be driven by the hormones estrogen and progesterone, and therefore endocrine therapies may benefit you. HER2 testing may be done via 1 of 2 methods. If the test was immunohistochemistry (IHC) then the results are reported as 0, 1+, 2+ or 3+. If you are 3+, then you will be classified as “HER2 positive”. The 2+ status is a grey area, and the guidelines state that the other test should be used to confirm whether HER2 gene copy number is increased.
The mastectomy pathology report is more complex. There will be a lot more details about what was found in each piece of the tumor – since it must be chopped up into small pieces to be processed and made into slides. Not only will you have breast tissue among these specimens, you will have lymph nodes and surrounding tissue. The summary should include the same factors as the diagnosis report as well as the number of positive lymph nodes out of the total number that were removed. If a lymph node metastasis has burst out of the lymph node, then this is called extra-capsular extension, and should be noted. This is a sign of additional aggressiveness and lack of response to chemotherapy. Another thing to note about the breast is that when it is removed from your body, it is marked by different colors of ink representing the orientation. The ink serves as a way for the surgeon to know where to look if the pathologist says that the edge is not free from cancer. The edge is called a margin. If there is cancer in the inked area, then the margin is “positive” and this is not good! The surgeon will be asked to cut more out if this is the case. Your report should state that the final margin is free of cancer. If the margin cannot be made “clean” – this is an important fact for you to glean from your report, since this should influence your radiation and your potential recurrence risk.
The one section of the report that you may be less interested in is what the tissue looked like by the naked eye. This is called the gross description. Microscopic cancer cells can’t be seen by eye unfortunately.
My ER/HER2 status changed after surgery? Why? Is it real? What does this mean for my treatment?
A change in marker status between your biopsy and final pathology after surgery is not uncommon. You may wonder why, and in most cases we do not know for definite. However what we do know is that a biopsy is only a small sample that may only contain a few thousand tumor cells. This is particularly true in IBC because there may not be a solid mass to sample, and the tumor cells may be in small nests throughout the skin. Another very important thing to know is that not all tumor cells are alike, and so one area may be HER2 positive while the rest is HER2 negative. If you sampled each area, you could get a different answer. Therefore at final pathology a larger area of tumor will be examined, and therefore could pick up differences like this. The scientific terminology for this is “intratumor heterogeneity”. Another difference may be the relative resistance or sensitivity of different clones to therapy – the surgical sample will only tell us about the cells that survived chemotherapy and targeted therapies (if relevant). We know in general that some ER+ cells are more chemo-resistant (and hormone-sensitive), and so a greater portion of these may be leftover than at the beginning. So in summary yes, the differences are indeed real. As for the meaning of these changes, usually if you gain a marker, then you will receive extra drugs that target these proteins (ie endocrine therapy or Herceptin). This is because the potential harms from not treating exceed the tiny risk of unnecessary treatment. In the case of becoming TNBC, the situation is a little more complex. Most oncologists would continue the treatments that have begun or were recommended based on biopsy, in case the already disseminated micro-metastatic cells still have these markers. However, there is no randomized high quality data that this is the best approach that improves survival. As with many decisions, your oncologist should personalize the approach based on your circumstances.
Should I get an Oncotype test? What does this test tell you?
You may have heard or read about the Oncotype DX test that is sometimes in used in early stage breast cancer. It is not relevant in IBC. The Oncotype DX test is used in patients with early stage cancers that are removed surgically shortly after diagnosis. The reason this test was designed was to identify those patients who do not require systemic chemotherapy because their risk of recurrence is too low to derive a significant benefit. Oncotype DX is a molecular gene expression test that quantifies the aggressiveness of the breast cancer and provides the oncologist a score that can be related to a risk of recurrence. If the score is low enough, then chemotherapy can be skipped, and since these patients are usually ER+, endocrine therapy is the treatment recommended after surgery. Since in IBC, everyone gets chemotherapy upfront, there is no use for this test.
How soon after surgery should I begin radiation?
About 4 weeks is about the average recovery period between surgery and radiation. Sometimes range of motion can be impacted by the modified radial mastectomy and if your drains are in for a longer period than usual, sometimes radiation must be postponed. Your physician will suggest exercises to help retain or regain range of motion, so you can lay comfortably with your arm elevated or extended while receiving radiation.