Understand your cancer report
A report can be full of unfamiliar words. These plain-language explanations tell you what a phrase means, what it does not prove, and what to ask — so the conversation with your care team makes more sense.
These pages explain report language in general. They cannot interpret your personal report — only your care team can do that.
Have the whole report in front of you? The report highlighter marks every term we explain, including scores like BI-RADS 4A or Gleason 4+3=7, and links each one to its page. Your text stays in your browser.
Most-searched report language
Common report terms, explained
These terms show up in pathology, imaging, lab, biomarker, and oncology notes. Each link goes straight to a plain-language explanation.
- ECOG performance statusHow activity level may be recorded in oncology notes and trial criteria.
- Karnofsky performance statusAnother common score for function, symptoms, and treatment planning.
- TNM stagingTumor, Node, and Metastasis language used to describe spread.
- BI-RADS 4What this mammogram category can mean and what usually happens next.
- Oncotype DX scoreHow recurrence-score language can come up in breast cancer decisions.
- MammaPrint scoreWhat a genomic-risk result can and cannot tell by itself.
- M-protein spikeA lab term people often see in myeloma and related blood-work conversations.
- PSA densityHow PSA is sometimes interpreted with prostate size and other risk details.
- EGFR exon 20A lung-cancer biomarker phrase that can affect treatment questions.
Watch: report explainers
Short captioned videos that walk through each kind of report in plain language.
How to read a cancer pathology report3 min · Captioned
Biopsy results, explained3 min · Captioned
Cancer staging and TNM, explained3 min · Captioned
Grade vs. stage — what's the difference?2 min · Captioned
Surgical margins, explained2 min · Captioned
Tumor markers, explained3 min · Captioned
How to read a CT or MRI report3 min · Captioned
Pathology report language
The words a pathologist uses to describe tissue removed by biopsy or surgery.
- What Does "Positive Margin" Mean in a Pathology Report?A positive margin means cancer cells were found at the edge of removed tissue. What that does and doesn't mean, and what to ask your care team.
- What Do "Negative" and "Close" Margins Mean?A negative (clear) margin means no cancer cells were seen at the edge of removed tissue. A close margin is nearby. What each means and what to ask.
- What 'Poorly Differentiated' Means on Your Report"Poorly differentiated" describes how abnormal cancer cells look under the microscope. What differentiation and grade mean, and what to ask your team.
- What Does "Lymphovascular Invasion" Mean?Lymphovascular invasion (LVI) means cancer cells were seen inside small blood or lymph vessels in the tissue sample. What it suggests and what to ask.
- What Does "Positive Lymph Node" Mean?Positive Lymph Node explained in plain English: what it can mean, what it cannot prove, and what to ask next.
- What Does "High Grade" Mean?High Grade explained in plain English: what it can mean, what it cannot prove, and what to ask next.
- What Does "Low Grade" Mean?Low Grade explained in plain English: what it can mean, what it cannot prove, and what to ask next.
- What Does Pathologic Complete Response Mean?pathologic complete response: what it usually means, what it does not prove, and what to ask next.
- What Does "Suspicious For Malignancy" Mean?Suspicious For Malignancy explained in plain English: what it can mean, what it cannot prove, and what to ask next.
- What Does "Cannot Exclude Malignancy" Mean?Cannot Exclude Malignancy explained in plain English: what it can mean, what it cannot prove, and what to ask next.
- What Does Breslow Depth Mean on a Melanoma Report?Breslow depth is how thick a melanoma is, measured in millimeters. What the number means, how it sets the T category, and what to ask.
- What Does Clark Level Mean on a Melanoma Report?Clark level describes which layer of skin a melanoma reaches, from I to V. What each level means and how it compares with Breslow depth.
- What Does Ulceration Mean on a Melanoma Report?Ulceration means the skin over a melanoma has broken down. What "ulceration present" or "absent" means on a report and how it affects staging.
- What Do In-Transit and Satellite Metastases Mean in Melanoma?Satellite, microsatellite, and in-transit metastases are small spots of melanoma near the main tumor. What each term means and how it is staged.
- What Does Extraprostatic Extension Mean?Extraprostatic extension means prostate cancer has grown just beyond the edge of the prostate. What it means on a report and how it is staged (pT3a).
- What Does Seminal Vesicle Invasion Mean?Seminal vesicle invasion means prostate cancer has grown into the seminal vesicles. What it means on a report, how it is staged (pT3b), and what to ask.
- What Does Tumor Deposit Mean on a Colon Cancer Report?Tumor deposits are small clumps of cancer in the fat near the bowel, apart from lymph nodes. What they mean on a colon cancer report and what N1c means.
Biomarkers
Features tested on the cancer that can guide treatment choices.
- What Does HER2 Positive, Negative, or Low Mean?HER2 is a protein tested on some cancers, especially breast cancer. What HER2 positive, negative, and low mean, and how they guide treatment options.
- What Does "Triple-Negative" Breast Cancer Mean?Triple-negative means a breast cancer tests negative for estrogen receptors, progesterone receptors, and HER2. What that means for treatment options.
- What Does an EGFR Mutation Mean?An EGFR mutation on a lung cancer report points to specific pills. Which exon it's in decides which ones, and why immunotherapy is usually held back.
- What Does an ALK Rearrangement Mean?ALK rearrangement explained for patients: what it is, why it may affect treatment options, and what to ask about testing.
- What Does a KRAS G12C Mutation Mean?KRAS G12C explained for patients: what it is, why it may affect treatment options, and what to ask about testing.
- What Does a BRAF V600E Mutation Mean?BRAF V600E explained for patients: what it is, why it may affect treatment options, and what to ask about testing.
- What Does PD-L1 TPS Mean?PD-L1 TPS explained for patients: what it is, why it may affect treatment options, and what to ask about testing.
- What Does PD-L1 CPS Mean?PD-L1 CPS explained for patients: what it is, why it may affect treatment options, and what to ask about testing.
- What Does MSI-H Mean on a Report?MSI-H on a tumor report means high microsatellite instability. What it can mean for immunotherapy, how it relates to Lynch syndrome, and its limits.
- What Does dMMR Mean on a Cancer Report?dMMR means deficient mismatch repair. The four proteins, how it relates to MSI-H, the two drugs approved on this marker alone, and their response rates.
- What Does TMB-High Mean on a Report?TMB-high explained for patients: what it is, why it may affect treatment options, and what to ask about testing.
- What Does an NTRK Fusion Mean?NTRK fusion explained for patients: what it is, why it may affect treatment options, and what to ask about testing.
- What Does HER2-Low Mean on a Report?HER2-low explained for patients: what it is, why it may affect treatment options, and what to ask about testing.
- What Does HRD-Positive Mean?HRD-positive explained for patients: what it is, why it may affect treatment options, and what to ask about testing.
- What Does a BRCA Tumor Mutation Mean?BRCA tumor mutation explained for patients: what it is, why it may affect treatment options, and what to ask about testing.
- EGFR Mutation in Lung CancerEGFR mutation in non-small cell lung cancer: why it matters, report wording, and questions to ask.
- ALK-Positive Lung Cancer: MeaningALK rearrangement or ALK fusion in non-small cell lung cancer: why it matters, report wording, and questions to ask.
- KRAS G12C in Lung Cancer: MeaningKRAS G12C in lung cancer: why it matters, report wording, and questions to ask.
- KRAS G12C in Colorectal CancerKRAS G12C in colorectal cancer: why it matters, report wording, and questions to ask.
- MSI-H Colorectal Cancer: MeaningMSI-H or dMMR in colorectal cancer: why it matters, report wording, and questions to ask.
- dMMR Endometrial Cancer: MeaningdMMR in endometrial cancer: why it matters, report wording, and questions to ask.
- BRCA Mutation in Ovarian CancerBRCA mutation in ovarian cancer: why it matters, report wording, and questions to ask.
- BRCA Mutation in Prostate CancerBRCA mutation in prostate cancer: why it matters, report wording, and questions to ask.
- HER2-Low Breast Cancer: MeaningHER2-low in breast cancer: why it matters, report wording, and questions to ask.
- HRD-Positive Ovarian CancerHRD-positive in ovarian cancer: why it matters, report wording, and questions to ask.
- What Does Circulating Tumor DNA Mean?circulating tumor DNA: what it usually means, what it does not prove, and what to ask next.
- What Does Tumor-Informed ctDNA Mean?tumor-informed ctDNA: what it usually means, what it does not prove, and what to ask next.
- What Does Minimal Residual Disease Mean?minimal residual disease: what it usually means, what it does not prove, and what to ask next.
- What Does Molecular Residual Disease Mean?molecular residual disease: what it usually means, what it does not prove, and what to ask next.
- What Does Signatera Mean?Signatera: what it usually means, what it does not prove, and what to ask next.
- What Does Guardant360 Mean?Guardant360: what it usually means, what it does not prove, and what to ask next.
- What Does PARP Inhibitor Mean?PARP inhibitor: what it usually means, what it does not prove, and what to ask next.
- What Does CAR T-Cell Therapy Mean?CAR T-cell therapy: what it usually means, what it does not prove, and what to ask next.
- What Does Antibody-Drug Conjugate Mean?antibody-drug conjugate: what it usually means, what it does not prove, and what to ask next.
Scan & imaging report language
Phrases radiologists use to describe what they see — and how sure they are.
- What Does "Ground-Glass Opacity" Mean on a Lung Scan?A ground-glass opacity (GGO) is a hazy area on a lung CT scan. It has many causes — most not cancer. What GGO means and what follow-up may involve.
- What Does a "Pulmonary Nodule" Mean on a Scan?A pulmonary nodule is a small spot in the lung found on imaging. Most are not cancer. What a nodule means and how doctors decide on follow-up.
- What Does BI-RADS Mean on a Mammogram Report?BI-RADS is a standard 0-to-6 scale radiologists use to summarize a mammogram result. Here's what each category means and what to ask.
- What Does BI-RADS 3 Mean?BI-RADS 3: what it usually means, what it does not prove, and what to ask next.
- What Does BI-RADS 4 Mean?BI-RADS 4: what it usually means, what it does not prove, and what to ask next.
- What Does BI-RADS 5 Mean?BI-RADS 5: what it usually means, what it does not prove, and what to ask next.
- What Does PI-RADS Mean on Prostate MRI?PI-RADS: what it usually means, what it does not prove, and what to ask next.
- What Does PI-RADS 1 or 2 Mean?PI-RADS 1 means very low and PI-RADS 2 means a low likelihood of significant prostate cancer on MRI. What a low score means and what it does not rule out.
- What Does LI-RADS Mean on a Liver Scan?LI-RADS: what it usually means, what it does not prove, and what to ask next.
- What Does Thyroid Nodule TI-RADS Mean?thyroid nodule TI-RADS: what it usually means, what it does not prove, and what to ask next.
- What Does TI-RADS 3 Mean?TR3 means a thyroid nodule scored 3 points on ACR TI-RADS, or mildly suspicious. Size then decides between a biopsy, follow-up scans, or neither.
- What Does Lung-RADS Mean on a Lung Screening CT?Lung-RADS is the category on a lung cancer screening CT report. What each category (1, 2, 3, 4A, 4B, 4X, S) means and what usually comes next.
- What Does O-RADS Mean on a Pelvic Report?O-RADS: what it usually means, what it does not prove, and what to ask next.
- What Does "Incidental Finding" Mean on a Scan?An incidental finding is something spotted on a scan that wasn't what the test was looking for. Most are harmless. What it means and what follow-up may involve.
- What Does "Suspicious" or "Indeterminate" Mean on a Scan?"Suspicious" and "indeterminate" describe how confident a radiologist is about a finding — not a diagnosis. What each means and what usually happens next.
- What Does 'Enhancing Lesion' Mean on MRI?An enhancing lesion is an area that becomes more visible after contrast. It is a clue, not a diagnosis.
- What Does 'Contrast Enhancement' Mean on a Scan?Contrast enhancement means a tissue or spot becomes easier to see after contrast. It is a scan feature, not a diagnosis.
- What Does 'Reactive Lymph Node' Mean?A reactive lymph node usually means the node looks active from immune response, often infection or inflammation, not automatically cancer.
- What Does 'Subcentimeter Lymph Node' Mean?Subcentimeter means smaller than one centimeter. A small lymph node can be normal, reactive, or occasionally still important depending on context.
- What Does 'Bone Lesion' Mean on a Scan?A bone lesion is an abnormal area in bone seen on a scan. It is a general term, not a diagnosis, and your care team uses more tests to find the cause.
- What Does 'Lytic Lesion' Mean on a Scan?A lytic lesion is an area where bone looks broken down or less dense. It can have benign, infection-related, or cancer-related causes.
- What Does "Hypodense Lesion" Mean?Hypodense Lesion explained in plain English: what it can mean, what it cannot prove, and what to ask next.
- What Does "Hypoattenuating Lesion" Mean?Hypoattenuating Lesion explained in plain English: what it can mean, what it cannot prove, and what to ask next.
- What Does "Sclerotic Lesion" Mean?Sclerotic Lesion explained in plain English: what it can mean, what it cannot prove, and what to ask next.
- What Does "Solid Mass" Mean?Solid Mass explained in plain English: what it can mean, what it cannot prove, and what to ask next.
- What Does "Cystic Mass" Mean?Cystic Mass explained in plain English: what it can mean, what it cannot prove, and what to ask next.
- What Does "Interval Growth" Mean?Interval Growth explained in plain English: what it can mean, what it cannot prove, and what to ask next.
- What Does "Stable Nodule" Mean?Stable Nodule explained in plain English: what it can mean, what it cannot prove, and what to ask next.
- What Does "SUV Max" Mean?SUV Max explained in plain English: what it can mean, what it cannot prove, and what to ask next.
- What Does "Mild Uptake" Mean?Mild Uptake explained in plain English: what it can mean, what it cannot prove, and what to ask next.
- What Does "Borderline Enlarged Lymph Node" Mean?Borderline Enlarged Lymph Node explained in plain English: what it can mean, what it cannot prove, and what to ask next.
Stage, grade & response
How far the cancer has spread, how the cells look, and how treatment is working.
- Stage vs. Grade: What's the Difference?Stage describes how far a cancer has spread. Grade describes how abnormal the cells look. They answer different questions — here's how they fit together.
- What Does "No Evidence of Disease" (NED) Mean?"No evidence of disease" (NED) means tests can't detect cancer right now. How NED differs from "cured," and what it means for follow-up.
- Remission vs. No Evidence of Disease: What's the Difference?"Remission" and "no evidence of disease" overlap but aren't identical. What complete and partial remission mean, and how NED fits in.
- What Does 'Bone Metastasis' Mean?Bone metastasis means cancer has spread to bone from another part of the body. It is different from primary bone cancer.
Next step
Turn what you read into questions for the team who can interpret your report.
Looking for a single word? Try the glossary or site search. Getting ready for a visit? See Prepare for your appointment.
How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
Read more about our editorial process, our use of AI, and our corrections policy.
Spotted a problem? Report an error — a factual mistake, broken or outdated source, confusing wording, or anything that seems unsafe. Please do not include names, medical record numbers, dates of birth, addresses, or other identifying medical information in your report.
After using this page, do you understand what to do next?
Anonymous — we only record the answer, never who gave it.