Learning the language of medicine – decoding acronyms and reports

Breast Cancer Terminology: Learning a New Language (and How to Get Fluent)

This is the thing about being diagnosed with something new - there is a whole new vocabulary, terminology, and acronyms you need to learn. A new language altogether, and without it, you can't comprehend half of what the medical team is saying. My first appointment was horrible - half of what was presented I could not understand (even though I was hearing multiple times how lucky I was I couldn’t have felt further from that). But I am an engineer and researcher by nature, and on top of it, I have the toxic trait of thinking I can learn anything I put my mind to. So of course, I went into hyperfocus mode to learn.

To me, that was an important point in gaining back some level of control over my life that the cancer diagnosis took from me. It also allowed me to ask questions, advocate, and understand—to have a say in how I wanted to proceed during the course of treatment. This post is an attempt to explain what I learned during this process. I am no medical expert; I am simply trying to translate things into plain language. If you need more details, I am listing a series of good medical resources here, which I used as references for this post.

What Breast Cancer Is: The Basics

The first thing you need to learn is what cancer is: in a nutshell, it is an abnormal growth and division of cells. “Cancer” is a broad term that covers many specific diseases. Breast cancers are defined by which type of cells are affected by this abnormality. Carcinomas, the most common form, mean that the disease affects the epithelial cells that line an organ. This makes up the majority of breast cancer diagnoses. Also, in looking at where the cancer originated (not only the type of cells), it can be ductal—also the majority, originating in the milk ducts—and lobular, which is the minority of diagnoses, originating in the milk glands.

The next term we need to get familiar with is In Situ vs Invasive. And to help understand it, think about the milk ducts as pipes. Normal ducts are clean and without any abnormal cells (and here, to use the pipe analogy, we will be using the rust reference). So they are pipes with no rust. When some rust starts to show (or abnormal cells growths) but still contained in the pipe, is what is called "in situ" - or pre-cancer. If left untreated, it can evolve to an invasive form.

Invasive is when the rust formation is big enough that makes the pipe "burst" and the rust is now out and about. That means the cells are now beyond the duct and it is now officially a cancer.

Source: Westmead Breast Cancer Institute

Breast Cancer Diagnosis Terms Explained

When you first hear the word “biopsy,” it can sound intimidating, but at its core, it simply means doctors are taking a small sample of tissue to figure out what’s going on. There are a few ways this can be done: sometimes with a core needle, which takes a bigger sample; other times with a fine needle, which is quicker but gathers less; and occasionally through a surgical biopsy, which removes a larger piece. Once the sample is collected, pathologists look at it under a microscope—this step is called histology. They’re checking how the cells are built and how “normal” or “abnormal” they look.

From there, the cancer gets a grade using something called the Nottingham system, which is just a fancy way of saying they measure how much the cells look like healthy ones, how unusual their shape is, and how fast they seem to be dividing. The lower the grade, the more positive the prognosis is.

Source: Johns Hopkins Medicine

Doctors also describe the cancer’s stage using the TNM system—T for the size of the tumor, N for whether lymph nodes are involved, and M for whether it has spread to other parts of the body. To put it more simply, Stage 0 means the cancer hasn’t invaded beyond where it started (like DCIS, which is non-invasive), Stage I and II usually mean it’s still small or only in nearby areas, Stage III indicates it has grown larger or spread to more lymph nodes, and Stage IV means it has traveled to distant organs like bones, lungs, or liver. Knowing the stage helps the care team decide on the best treatment plan.

Source: VeryWell Health

Another set of terms you’ll hear often are about receptors, which are like little “on/off switches” on the outside of cancer cells. If a cancer is called ER+ (estrogen receptor positive) or PR+ (progesterone receptor positive), it means those hormones are helping the cancer grow—almost like fuel. The good news is that there are treatments (hormone therapies) that can block those signals and slow or stop the cancer. On the other hand, HER2+ means the cancer cells have extra copies of a protein called HER2, which makes them grow faster and more aggressively. That used to sound scary, but today there are highly effective targeted therapies that specifically shut down HER2’s “overdrive” switch. Knowing whether your cancer is ER, PR, or HER2 positive is a key part of figuring out the best treatment plan.

Finally, you may hear about margins after surgery. If the report says “clear margins,” it means no cancer cells were found at the edge of the removed tissue (that’s good news). If it says “positive margins,” some cancer was still left behind, which usually means more treatment is needed.

Common Acronyms You’ll Hear

• TNBC (Triple Negative Breast Cancer)

• DCIS (Ductal Carcinoma In Situ)

• IDC (Invasive Ductal Carcinoma)

• LCIS (Lobular Carcinoma In Situ)

• LC – Invasive Lobular Carcinoma: the second most common invasive type, starting in the milk-producing glands.

• ER+ / PR+ – Estrogen Receptor Positive / Progesterone Receptor Positive: cancers that grow in response to these hormones.

• HER2+ – Human Epidermal Growth Factor Receptor 2 Positive: cancers that have extra HER2 protein, often treated with targeted therapy.

• HR+ – Hormone Receptor Positive: a shortcut term when either ER+ or PR+.

• pCR – Pathologic Complete Response: no cancer is found in tissue after treatment (often used with chemo).

• NED – No Evidence of Disease: what everyone wants to hear after treatment.

• BIRADS – Breast Imaging Reporting and Data System: a scale used in imaging (like mammograms) to describe findings.

It’s a lot, I know—and this is just a snapshot of the vocabulary you’ll come across. But here’s the good news: you don’t need to memorize it all right away…

Don't worry! Eventually you will get fluent at it

I won’t lie—it’s hard. Overwhelming at first, and honestly, overwhelming again the second and third time too. Your head will hurt from trying to absorb every new word. But please remember this: you don’t have to understand everything right away. Take in what you can, ask questions when you feel ready, and give yourself permission to just breathe through the rest. Over time, things that once sounded like a foreign language will start to click. You’ll catch yourself recognizing terms, piecing together meanings, and even speaking them with confidence. And with that fluency comes something precious—comfort, a little control, and the quiet confidence that you’re not just being carried through this, but walking your own path in it.