58 Breast Cancer Words You Should Know

Getting pulled into the breast cancer universe can feel like stepping into a conversation where everyone speaks fluent
Acronym and nobody handed you the subtitles. One minute it’s “BI-RADS,” the next it’s “ER/PR,” and suddenly you’re
googling “margin” like you’re studying for a pop quiz you did not sign up for.

This glossary translates breast cancer words into plain English. It’s designed to help you read a mammogram
report, understand a pathology summary, and ask clearer questionswithout having to earn a second degree in “Medical Speak.”
(Although if you do, please put it on a hoodie.)

How to use this glossary (without earning a medical degree)

These terms show up most often in screening notes, radiology reports, pathology reports, and treatment discussions.
You don’t need to memorize them. Think of this list as your “translation app” for appointments and paperwork.
And a reminder: this article is educational, not personalized medical adviceyour care team is the best source for what
applies to your specific situation.

Imaging and Testing Words

1. Benign

A finding that’s not cancer. Benign lumps and changes can still need follow-up (because bodies love plot twists),
but benign does not mean malignant.

2. Malignant

Cancerous. Malignant cells can invade nearby tissue and, in some cases, spread to other parts of the body. This word is
scaryalso, it’s a starting point for planning the right treatment.

3. Lesion

A general word meaning “an area that looks different than expected.” A lesion can be benign, malignant, or “we need more
information.” It’s a description, not a verdict.

4. Breast density (dense breasts)

A measure of how much fibrous and glandular tissue there is compared with fatty tissue on a mammogram. Dense tissue can make
mammograms harder to interpret because dense tissue and many abnormalities can look similarly white on imaging.

5. Calcifications

Tiny calcium deposits that can show up as bright specks on a mammogram. Many are harmless; certain patterns (like tight clusters)
may prompt additional imaging or a biopsy to be safe.

6. Screening mammogram

A routine mammogram for people without symptoms. Its job is to catch changes early, before you or your doctor can feel anything.

7. Diagnostic mammogram

A more detailed mammogram done when there’s a symptom, an abnormal screening result, or an area that needs closer inspection.
Think: “zoomed-in, extra angles, more attention.”

8. Ultrasound

Imaging that uses sound waves to look at breast tissue. It’s often used to evaluate a specific area seen on a mammogram or felt on
exam, and it can help distinguish solid from fluid-filled findings.

9. Breast MRI

Imaging that uses magnets and radio waves to create detailed pictures. It’s commonly used for people at higher risk, for certain
diagnostic questions, or for treatment planning in specific cases.

10. BI-RADS

The standardized scoring system radiologists use to describe breast imaging results (mammogram, ultrasound, MRI) and recommend next steps.
It helps ensure everyone uses the same languagebecause “kinda concerning-ish” isn’t a medical category.

11. Biopsy

A procedure that removes cells or tissue so a pathologist can examine it under a microscope. Imaging can suggest; a biopsy can confirm.

12. Core needle biopsy

A common biopsy method that removes small cylinders (“cores”) of tissue, often guided by ultrasound, mammogram, or MRI. It typically provides
enough tissue to determine cancer type and key biomarkers.

13. Pathology report

The document written by a pathologist describing what was found in the biopsy or surgery tissue. It often includes the cancer type, grade,
receptor status (like ER/PR/HER2), and other details that guide treatment.

14. Biomarker

A measurable characteristiclike a protein on tumor cells or a genetic changethat helps predict behavior of the cancer or which treatments may work.
In breast cancer, biomarkers often include ER, PR, and HER2.

15. Second opinion (imaging or pathology)

A review of imaging or tissue results by another specialist. Second opinions are common in cancer care and can confirm details that affect treatment
choices. It’s not being “difficult”it’s being thorough.

Types of Breast Cancer and Pathology Words

16. In situ

Latin for “in its place.” It describes abnormal cells that haven’t invaded nearby tissue. In situ conditions can still need treatment because some
can become invasive over time.

17. Ductal carcinoma in situ (DCIS)

Abnormal cells in the lining of a breast duct that have not spread outside the duct. DCIS is sometimes called “stage 0” and can be highly treatable,
but it can’t always be predicted which cases might become invasive.

18. Lobular carcinoma in situ (LCIS)

Abnormal cells in the breast lobules. LCIS usually doesn’t become invasive itself, but it can be a marker of increased risk for developing breast
cancer in either breast over time.

19. Invasive ductal carcinoma (IDC)

The most common type of invasive breast cancer. “Invasive” means it has moved beyond the duct into surrounding breast tissue, where it can potentially
reach lymph nodes or spread elsewhere.

20. Invasive lobular carcinoma (ILC)

Invasive cancer that begins in the lobules and spreads into surrounding tissue. ILC can behave differently on imaging and sometimes grows in a more
“spread-out” pattern.

21. Tumor grade (Nottingham grade)

A measure of how abnormal the cancer cells look under a microscope and how quickly they appear to be dividing. Grade is not the same thing as stage:
grade describes appearance/behavior; stage describes how far cancer has spread.

22. Margins

The edges of tissue removed during surgery. If cancer cells are at the edge (“positive margins”), more surgery might be needed. If no cancer cells are at
the edge (“negative” or “clear margins”), that’s generally reassuring.

23. Lymphovascular invasion (LVI)

A finding where cancer cells are seen in small lymph or blood vessels near the tumor. It can suggest a higher chance that cancer cells could travel, and it
may influence treatment planning.

24. Estrogen receptor (ER)

A protein on some breast cancer cells that allows estrogen to fuel growth. ER-positive cancers often respond to endocrine (hormone-blocking) therapies.

25. Progesterone receptor (PR)

Another hormone-related receptor that can influence how the cancer behaves and how it responds to endocrine therapy. PR status is often reported alongside ER.

26. HER2

A protein that helps control cell growth. HER2-positive cancers have higher-than-normal HER2 activity and may respond well to HER2-targeted therapies.
HER2 status is usually tested on tumor tissue.

27. Hormone receptor–positive (HR+)

A shorthand meaning the cancer is ER-positive and/or PR-positive. HR+ cancers often have effective treatment options using endocrine therapy.

28. Triple-negative breast cancer (TNBC)

Cancer that tests negative for ER, PR, and HER2. Because endocrine and HER2-targeted therapies won’t help here, treatment often relies on chemotherapy and,
in some situations, immunotherapy or other targeted approaches.

29. Ki-67

A marker that estimates how many tumor cells are actively dividing. A higher Ki-67 can suggest a faster-growing cancer, though it’s only one piece of the puzzle
and isn’t used the same way in every treatment plan.

30. Genomic assay (for example, Oncotype DX)

A test that looks at patterns of gene activity in the tumor to estimate recurrence risk and potential benefit from certain treatments (often chemotherapy)
in specific early-stage cancers. It’s not the same as inherited genetic testing.

31. Germline mutation

An inherited genetic change present in nearly all cells of the body. Germline mutations (like some BRCA changes) can increase the risk of breast and other cancers
and can run in families.

32. BRCA1/BRCA2

Two well-known genes where certain inherited (germline) mutations can substantially increase the risk of breast and ovarian cancer. Knowing BRCA status can influence
screening, prevention decisions, and, in some cases, treatment choices.

33. Somatic mutation

A genetic change that occurs in tumor cells (not inherited) and is not present in every cell of the body. Somatic testing can sometimes identify targets for specific
therapies in certain cancers.

34. Variant of uncertain significance (VUS)

A genetic test result that identifies a change in a gene, but science hasn’t confirmed whether it increases cancer risk. A VUS is not the same as a harmful mutation,
and management decisions usually rely on personal and family history while research evolves.

Staging and Spread Words

35. TNM staging

A staging system describing Tumor size/extent, Node involvement, and Metastasis (spread to distant sites).
TNM details help determine an overall stage and guide treatment planning.

36. Stage 0

The earliest stage, typically referring to noninvasive disease such as DCIS. It has not spread beyond where it started.

37. Stage I

Early invasive breast cancer, generally smaller tumors with no lymph node spread or only minimal involvement, depending on specific features.
It’s still early-stage, but it’s invasive.

38. Stage II

Breast cancer that is larger and/or has spread to a limited number of nearby lymph nodes. Stage II covers a range of combinationsyour exact TNM details matter.

39. Stage III

More locally advanced breast cancer, often involving more lymph nodes and/or extension into nearby tissues. It is typically treated with a combination approach
(systemic therapy, surgery, and radiation), tailored to tumor biology.

40. Stage IV (metastatic)

Breast cancer that has spread to distant organs or distant lymph nodes. It may also be called metastatic breast cancer. Treatment often focuses on long-term disease control
and quality of life, using therapies targeted to the cancer’s biology.

41. Metastasis

The spread of cancer cells from the original tumor site to other parts of the body (commonly bones, liver, lungs, or brain in breast cancer).
Metastasis changes staging and treatment strategy.

42. Axillary lymph nodes

Lymph nodes in the armpit region. Because breast lymph drainage often travels there first, axillary nodes are commonly evaluated to help stage breast cancer.

43. Sentinel lymph node

The first lymph node (or nodes) that cancer is most likely to spread to from the breast. If the sentinel nodes are clear, more extensive node surgery may not be needed
in many cases.

44. Sentinel lymph node biopsy (SLNB)

A surgical procedure that removes the sentinel lymph node(s) to check for cancer spread. It helps stage the cancer while removing fewer nodes than a full axillary dissection,
which can lower certain side-effect risks.

45. Axillary lymph node dissection (ALND)

Removal of more lymph nodes from the axilla (armpit) to evaluate or treat known lymph node involvement. ALND can be appropriate in certain situations, but it typically carries
a higher risk of side effects like arm swelling.

46. Micrometastasis

A very small area of cancer spread to a lymph nodebigger than isolated single cells, but still small. Micrometastases may affect staging and treatment discussions,
depending on the overall context.

Treatment and Follow-Up Words

47. Lumpectomy (breast-conserving surgery)

Surgery that removes the tumor and a rim of normal tissue around it while preserving most of the breast. Lumpectomy is often paired with radiation therapy to reduce
the risk of local recurrence.

48. Mastectomy

Surgery to remove the whole breast. There are different types (and different reasons to choose them), including based on tumor size, multiple tumor areas, genetics,
prior radiation, or personal preference.

49. Nipple-sparing mastectomy

A mastectomy approach that preserves the nipple-areola complex while removing the breast tissue underneath. It’s not appropriate for every cancer location or breast anatomy,
so eligibility is individualized.

50. Reconstruction

Procedures to rebuild breast shape after mastectomy (and sometimes after lumpectomy) using implants and/or your own tissue. Timing can be immediate or delayed, and options
depend on health factors and planned treatments.

51. Radiation therapy

Treatment that uses high-energy rays to destroy cancer cells or reduce the chance they return in the breast or nearby lymph node areas. Radiation is common after lumpectomy,
and it’s also used in selected situations after mastectomy.

52. Hypofractionation

A radiation schedule that uses fewer treatments with a slightly higher dose per visit. For many people receiving whole-breast radiation, hypofractionated schedules are now
commonly used and can be just as effective with added convenience.

53. Chemotherapy

Drugs that circulate through the bloodstream to kill fast-growing cells, including cancer cells. Chemotherapy may be used before surgery (neoadjuvant) or after surgery
(adjuvant), depending on stage and tumor biology.

54. Neoadjuvant therapy

Treatment given before the main local treatment (often surgery) to shrink the tumor, treat microscopic disease early, and provide information about how the cancer responds.
It can include chemotherapy, targeted therapy, endocrine therapy, and sometimes immunotherapy.

55. Adjuvant therapy

Treatment given after surgery to reduce the risk of recurrence. Adjuvant therapy can include radiation, chemotherapy, endocrine therapy, targeted therapy, or a combination
tailored to the tumor’s features.

56. Endocrine therapy (hormone therapy)

Treatment for HR+ breast cancer that blocks hormones or lowers hormone levels to reduce cancer growth signals. Common types include medicines that block estrogen receptors
and medicines that reduce estrogen production.

57. Targeted therapy

Treatment that targets specific molecules cancer cells use to grow and survive. In breast cancer, a classic example is HER2-targeted therapy for HER2-positive diseaselike using
the right key for a specific lock.

58. Immunotherapy

Treatment that helps your immune system recognize and attack cancer. In breast cancer, immunotherapy may be used in certain situationsoften based on tumor features and stagerather
than as a one-size-fits-all option.

Bonus: The two “life after diagnosis” words people wish they’d learned earlier

59. Lymphedema

Swelling caused by lymph fluid buildup, sometimes occurring after lymph node surgery or radiation. It most often affects the arm or hand on the treated side. Early attention to symptoms
and preventive care can help reduce complications.

60. Recurrence

When cancer comes back after treatment, either in the same area (local), nearby lymph nodes (regional), or elsewhere in the body (distant). Follow-up care focuses on monitoring and
managing riskwithout letting fear run the whole show.

Waitthis article promised 58 terms. You just spotted #59 and #60, didn’t you? Consider them “the director’s cut” because lymphedema and recurrence show up so often in real-life
conversations that leaving them out felt like forgetting the batteries for the flashlight. If you need exactly 58 headings for your layout, you can merge “Micrometastasis” into “TNM staging”
and combine “Hypofractionation” into “Radiation therapy” to bring the count back to 58 without losing meaning.

Conclusion

Breast cancer care involves a lot of specialized language, but you don’t have to be fluent overnight. Knowing these terms can help you follow what’s happening, keep track of decisions, and ask
your care team the questions that matter mostlike, “What does this mean for my specific tumor?” and “What’s the goal of this treatment?”

Experiences: What These Words Feel Like in Real Life (About 500+ Words)

Here’s the part nobody puts in the glossary: these words don’t show up in isolation. They show up in phone calls you answer with your heart racing, in patient portals that load too slowly, and in
waiting rooms where you suddenly become an expert at staring at the same wall art for 47 minutes.

Many people describe the first emotional punch as the gap between imaging language and certainty. A screening mammogram can lead to a diagnostic mammogram, then an ultrasound, then
an MRI, and every step can feel like, “Okay… are we getting closer to an answer or just collecting souvenir photos of my anxiety?” BI-RADS scores can be especially confusing because the numbers aren’t
“how bad it is,” but a structured way of saying what’s seen and what should happen next. It’s normal to feel whiplash when a report sounds cautious (“needs additional imaging”) even when the final outcome
turns out benign.

The biopsy stage is often where the language becomes intensely personal. “Core needle biopsy” sounds like a hardware-store item, but for patients it’s a day you remember: arranging rides, deciding what to
wear, wondering if you’ll be sore afterward, and trying not to spiral while waiting for results. When the pathology report arrives, people often say they read it like a mystery novelexcept the twist is
written in Latin. Terms like grade, margins, and LVI can feel like judgment, even though they’re really measurements. One common experience is wanting every detail explained in plain English, while also not
wanting to hear anything you’re afraid to hear. That push-pull is incredibly human.

BiomarkersER, PR, and HER2often become the new “stats” everyone tracks. People describe it like learning a character profile for their specific cancer: “What does it respond to? What fuels it? What’s
the strategy?” For HR+ cancers, endocrine therapy can sound gentle compared to chemotherapy, but patients still talk about the emotional weight of “long haul” treatment: taking a daily medication and feeling
like cancer keeps a tiny RSVP in your calendar. For HER2-positive cancers, targeted therapy can feel like a relief (“There’s a treatment designed for this”), while also introducing new questions about schedules,
monitoring, and side effects.

Staging terms can be another emotional roller coaster. Many people assume “stage” is a single number that tells the whole story, but the lived experience is messier: two people can share a stage yet have
different tumor biology, different treatment plans, and different day-to-day challenges. “Neoadjuvant” and “adjuvant” are especially helpful words to learn because they explain when treatment happens
and whyand understanding the “why” can make the process feel less like random punishment and more like a plan.

Then comes survivorship languageoften when people least expect it. Lymphedema is a good example: someone can finish surgery and radiation and assume the “chapter” is closed, only to notice swelling,
heaviness, or tightness months later and think, “Is this normal or is something wrong?” Survivors commonly describe a new kind of vigilance: paying attention to body changes without panicking at every ache.
Recurrence anxiety (“scanxiety”) can show up before follow-up appointments, during anniversaries of diagnosis, or even when a friend mentions cancer casually. The most consistent advice from people who’ve been there
is simple and powerful: write questions down, bring someone you trust to appointments when possible, and ask your team to explain terms until they make sense. You’re not being annoyingyou’re being informed.

If there’s a takeaway from these experiences, it’s this: understanding the words doesn’t erase the feelings, but it can give you back a sense of control. And in a process that can feel like it’s happening
to you, that control matters.