Welcome back to an introduction to breast cancer. I'm Dr. Anees Chagpar. The last time we met, we talked a little bit about screening. We looked at mammograms and ultrasounds and talked about MRI. When we talked about all of that, we looked at these images and we said some things look suspicious, some things don't look suspicious. But how do you actually make the diagnosis of cancer? It's with a biopsy. So today, we're going to talk about different biopsy types, the advantages and disadvantages of each, that ultimately give us that diagnosis of breast cancer. Let's get started. Remember back to that BIRADS lexicon. This is a scale that the radiologists use to tell us how suspicious they are based on the imaging findings that they have in front of them. Biopsies are only really recommended for those at which they have a reasonable level of suspicion. Bi-RADS 4 or B-IRADS 5 and remember even with a BI-RADS 4, there's only about a 25 to 50% probability that this will turn out to be cancer. Nonetheless, if there's something suspicious, we want to know what it is and so, we need a biopsy. I tell all my patients that there's only two people who can tell you anything for sure, God and the pathologist. That is to say that in order to get that diagnosis, looking at a mammogram is not sufficient. One of my medical oncology colleagues always used to say, tissue is the issue. We need that tissue to really confirm the diagnosis. And to give us all of the information we need about what kind of cancer this is, if it is a cancer at all. So, remember back to when we talked about types of cancer. We talked about invasive and in situ. True cancers that invaded the basement membrane, and had access to distant organs and in situ that stayed above the basement membrane that had no ability to spread. Well, biopsies can give us that information. We talked about types, we talked about cancers that came from the ducts, cancers that came from the lobules. Again, looking at the tissue under the microscope can give us that information. And what about receptors? We talked a little bit about estrogen receptor and progesterone receptor and another receptor called HER2. Again, the only way we're going to know whether these cancers are fed by estrogen and progesterone or whether they thrive on a signal from HER2 is if we actually have tissue that we can stain for these receptors. So how do we get that tissue anyways? That's where a biopsy comes in. But there are very many different types of biopsies, three main ones. The first is what's called a fine needle aspiration or an FNA. The second, which is really the work horse in breast cancer, is a core needle biopsy. And the third is an excisional biopsy. Let's look at the advantages and disadvantages of fine needle aspiration biopsy. A Fine Needle Aspiration biopsy or an FNA Is done with a tiny needle. Usually, it's a 22 to a 25 gauge needle, so often smaller than what you'd get with an intravenous. When you feel a mass in the office or the radiologist sees one with ultrasound, they can take a fine little needle and put it into the mass, draw back some cells and send those cells to the pathologist right in the office. It's a very easy and generally painless procedure. But it has some disadvantages, two big disadvantages. The first is that you only get cells. You don't get architecture. What do I mean by architecture? Well, you're not really taking a piece of the tissue, so you can't see, for example, whether these cells form tubules or not. It's hard for pathologists who are used to looking at tissue to really look at only cells. So you need an experienced cytopathologist, somebody who can look at these cells and say, how abnormal do these cells look like? Are these really cancer cells? The second big disadvantage also goes back to a lack of architecture which is to say that you don't have a basement membrane because, with cells, you don't know whether those abnormal cells are above the basement membrane or below the basement membrane. And you haven't given a pathologist a piece of actual tissue so that they can see where that basement membrane is. Fine Needle Aspirations are very nice if all you are doing is draining a cyst. But in general, most pathologists would prefer the next biopsy technique which is a core needle biopsy. Now core needle biopsies do use a slightly larger needle. Oftentimes the needle is about the size of this pen, so somewhere between an 8 to a 14 gauge needle. A little bit bigger than what you'd get with a standard intravenous. But the advantage of that is that you actually get a piece of tissue, a core, where you can provide architecture. Now the pathologist can look directly at this breast tissue and see where the basement membrane is. Are these cells forming ducts or are they in lobules? Do they form that single file pattern that we talked about? What truly is the grade of these cancers? And can get information with regards to receptor status as well, because they'll actually have the tissue there. However, the disadvantage of course is, it is a bigger needle. The third procedure is an excisional biopsy. Now, on the surface, many people would say, why not do an Excisional Biopsy. This is where you actually take out that lump. That way you've got all the tissue you need and you've actually taken out the lump. Wouldn't that be perfect? Well, not quite. While it's true that it does give you tissue and architecture so that the pathologist can really take a look at the specimen. The disadvantage is, that this is a surgical procedure and as we'll talk about with treatment, just removing the lump is rarely enough if all we're talking about is cancer. So we often want to establish a diagnosis but not necessarily remove the lump, before we have a chance to talk to our patients about all of the options for managing that cancer. So to do a surgical procedure to get a diagnosis, often means a second surgical procedure to actually treat the cancer. And who wants to go to an operating room twice? Well, in subsequent lectures, we're going to talk more about going to the operating room, how we surgically manage these cancers, and how we treat them with adjuvant, and indeed, neoadjuvant therapies. Adjuvant after surgery, neoadjuvant before surgery. Thanks for joining me. Until next time, I'm Dr. Anees Chagpar.
