1800 202 8726
IHC Markers Explained

CDX2 Positive: — What It Means in Your Report

Seeing CDX2+ on a pathology report is confusing when no one has explained what it means. CDX2 is a protein that intestinal cells normally make. Finding it in a tumour sample tells your team something important about where the cancer may have started.

Medically reviewed by Dr. T. Raghavender Reddy, Medical Oncologist, MBBS · DM (Medical Oncology) · MD (Radiation Oncology) · Last reviewed September 2026

  • Points to intestinal origin — CDX2 is a marker of intestinal tissue. When it is positive, the cancer likely started in the bowel or colon.
  • One marker among several — Your oncologist reads CDX2 alongside other stains. One result does not confirm a diagnosis on its own.
  • Most useful when origin is unclear — CDX2 is often ordered when a cancer has spread and the primary site has not yet been identified.
  • Negative is also informative — CDX2 negative does not mean the test failed. The absence of the stain is itself a useful finding.
4.8 · 800+ Google reviews · 15,000+ patients treated
Limited Slots Today

Get this explained properly

₹950   Today: FREE  ·  Including free written second opinion

Reply within 2 working hours
Report reviewed by a senior oncologist
Confidential. No commitment to start treatment.
or
Call 1800 202 8726
17+
Cancer Specialists
on Panel
96.9%
Breast Cancer
Survival Rate*
15,000+
Patients
Treated
4.8★
Google Rating
(800+ reviews)

CDX2 is a protein that intestinal cells normally make. When your pathology report says CDX2 positive, the tumour cells contain this protein — which suggests the cancer originated in the intestine or colon. This helps your oncologist identify where the cancer started, particularly when the primary site is still being established.

What do these terms on your report mean?

CDX2
A protein produced by the cells that line the intestine. In a pathology report, CDX2 is detected using a staining technique called immunohistochemistry.
CDX2 positive (CDX2+)
The stain found CDX2 protein in the tumour cells. This points toward intestinal or colorectal origin.
CDX2 negative (CDX2−)
The stain did not detect CDX2. This is informative, but it is read alongside the other markers in the panel — not as a standalone finding.
Immunohistochemistry (IHC)
A laboratory method that uses antibodies to detect specific proteins in a tissue sample. Results are reported as positive or negative, sometimes with a staining intensity score.
CK7 and CK20
Companion markers frequently ordered with CDX2. Colorectal cancers are typically CK20 positive and CK7 negative. A different pattern may point toward an upper GI or non-GI origin.
Cancer of unknown primary (CUP)
A situation where a cancer has spread to a secondary site — such as the liver or a lymph node — before the organ it started in has been confirmed. CDX2 is part of the standard investigation panel in this setting.

What does a CDX2 positive result tell your team?

  • Tumour cells carry a protein normally found in intestinal lining cells
  • The cancer is likely to have started in the large intestine, rectum, or small bowel
  • Some gastric cancers with intestinal-type features can also be CDX2 positive
  • CDX2 is read alongside other markers — one stain alone does not confirm origin
  • Your oncologist will interpret the full panel and explain what it means for your diagnosis

Still unclear?

Send your reports across and a specialist will walk you through what they mean — what is known, what is not, and what the options actually are.

Meet the Specialists

17+ senior cancer specialists. One panel for your case.

Trained at AIIMS, Tata Memorial, and leading international centres. Combined 150+ years of experience. Every complex case is reviewed by 3+ of them — together.

Dr. Naresh Gundu
Medical Oncologist

Dr. Naresh Gundu

MBBS, DNB (Internal Medicine), DM (Medical Oncology)

View Profile
Dr. C. Raghavendra Reddy
Medical Oncologist

Dr. C. Raghavendra Reddy

MBBS(Gold Medal), DNB(General Medicine), DM(Medical Oncology)(Gold Medal)

View Profile
Dr. Bharati Devi Gorantla
Medical Oncologist

Dr. Bharati Devi Gorantla

MBBS, MD(General Medicine), DM(Medical Oncology)(Adyar,Chennai), ECMO, MRCP SCE(UK)

View Profile
Dr. Owais Mohammed
Medical Oncologist

Dr. Owais Mohammed

MBBS, MD (General Medicine), DrNB (Medical Oncology), ECMO, MRCP SCE (Medical Oncology) (UK)

View Profile
Dr. T. Raghavender Reddy
Medical Oncologist

Dr. T. Raghavender Reddy

MBBS, DM (Medical Oncology), MD (Radiation Oncology)

View Profile
Dr. N. Kiranmayee
Medical Oncologist

Dr. N. Kiranmayee

MBBS, DM (Medical Oncology), MD (Internal Medicine)

View Profile
Dr. Muralidhar Muddusetty
Surgical Oncologist

Dr. Muralidhar Muddusetty

MBBS (AIIMS), MS (Surgery) (AIIMS), DNB (Surgical Oncology), MRCS (Edinburgh)

View Profile
Dr. Raghavendra Naik
Surgical Oncologist

Dr. Raghavendra Naik

MBBS, MS (General Surgery), M.Ch (Surgical Oncology)

View Profile
Dr. Mohammed  Imaduddin
Surgical Oncologist

Dr. Mohammed Imaduddin

M.B.B.S, MS (General Surgery), M.Ch (Surgical Oncology)

View Profile
Dr. Vinay Mamidala
Surgical Oncologist

Dr. Vinay Mamidala

MBBS, MS(General Surgery), M.Ch(Surgical Oncology), FMAS, FARIS(Ongoing)

View Profile
Dr. Paila Gowri Naidu
Surgical Oncologist

Dr. Paila Gowri Naidu

MBBS, MS (General Surgery), M.Ch (Surgical Oncology), FMAS

View Profile
Dr. Venkata Sushma P
Radiation Oncologist

Dr. Venkata Sushma P

MBBS, MD (Radiation Oncology)

View Profile
Dr. Kirti Ranjan Mohanty
Radiation Oncologist

Dr. Kirti Ranjan Mohanty

MBBS, MD (Radiation Oncology)

View Profile
Dr. Gangadhar Vajrala
Radiation Oncologist

Dr. Gangadhar Vajrala

MBBS, MD (Radiation Oncology), MPH

View Profile
Dr. Basudev Pokhrel
Hematologist

Dr. Basudev Pokhrel

MBBS, M.D (Immunohematology & Blood Transfusion)

View Profile
Dr. Mohammed Imran
Interventional Radiologist

Dr. Mohammed Imran

View Profile
Dr. Vajja Sandeep Kumar
Surgical Oncologist

Dr. Vajja Sandeep Kumar

MBBS, MS (General Surgery), DrNB (Surgical Oncology), FALS Oncology

View Profile
Dr. Sridhar Kamani
Surgical Oncologist

Dr. Sridhar Kamani

MBBS, MS (General Surgery), DrNB (Surgical Oncology)

View Profile

Want a specific doctor for your case? Mention them when booking.

Book Free Consultation

Get a straight answer from a specialist

45 minutes, your reports reviewed, your questions answered in plain language.

Book Free Consultation Call 1800 202 8726

Common questions about CDX2 results

Does CDX2 positive definitely mean colorectal cancer?

No. CDX2 positive points strongly toward intestinal origin, but several other cancers can also be CDX2 positive — including some cancers of the stomach, appendix, and small bowel. The pathologist reads CDX2 alongside other markers such as CK7, CK20, and SATB2, and alongside your imaging and clinical history. A single stain does not confirm a diagnosis.

What do CDX2, CK7, and CK20 together tell the pathologist?

Their combination is considerably more informative than any one marker alone. A pattern of CDX2 positive, CK20 positive, and CK7 negative is a finding strongly associated with colorectal origin. A different combination — for example CDX2 positive with CK7 positive — may point toward a gastric or upper GI primary. Your pathologist describes the pattern; your oncologist explains what it means for your diagnosis.

What if my colorectal cancer report says CDX2 negative?

Most colorectal cancers are CDX2 positive, but a proportion are not, and this does not overturn a diagnosis established through histology and clinical workup. CDX2 negativity in a confirmed colorectal cancer is additional information your oncologist and pathologist factor into your assessment. If you have questions about what this means for you, bring the report to your next appointment and ask.

Who should explain what CDX2 means for my treatment?

Your treating oncologist. Marker results are one part of a larger picture that includes your tumour histology, imaging, stage, and overall health. Treatment decisions follow from all of that together, not from the IHC panel alone. If you received a pathology report without a clear explanation of what the markers mean for you, that conversation belongs at your next oncology appointment.

Did you know?

CDX2 is considered one of the most reliable markers for intestinal origin in diagnostic pathology. Tumour cells often retain the proteins characteristic of the tissue they came from — which is what makes CDX2 useful even when a cancer has spread far from where it started.

Source: WHO Classification of Tumours of the Digestive System

Explore 112 more Markers, Molecular Testing and Test Accuracy topics

HUB — How Accurate Is a Biopsy? Repeats, Errors and Second Opinions

HUB — IHC and Molecular Markers on a Biopsy

HUB — Labs, Slides and Second Opinions on a Biopsy

All Markers, Molecular Testing and Test Accuracy →

Next step

Still not sure what applies to you?

Send your reports across and a senior medical oncologist will go through what they mean, what is known, and what the options actually are.

Book Free Consultation Call 1800 202 8726
Common questions

Frequently asked questions

What does CDX2 positive mean in plain language?

It means the laboratory found a protein called CDX2 in your tumour tissue. CDX2 is normally made by cells that line the intestine, so finding it in a tumour suggests the cancer likely began in the intestine or colon. It is one marker in a panel — your oncologist interprets the whole set of results together.

Does CDX2 positive mean I have colorectal cancer?

It points strongly toward intestinal origin, but a diagnosis is not made from one marker alone. The pathologist reads CDX2 alongside other stains and your tumour histology. Some stomach and small bowel cancers are also CDX2 positive. Your oncologist will use the complete report and your clinical picture to establish what type of cancer you have and where it started.

What other markers are usually reported alongside CDX2?

CK7 and CK20 are the markers most commonly ordered with CDX2 when GI origin is being investigated. SATB2 is sometimes added when the pathologist needs further evidence of lower GI origin. The combination is more informative than any single marker — a pattern of CDX2 positive, CK20 positive, and CK7 negative points toward colorectal origin, while other combinations may suggest a different primary site.

Can a colorectal cancer be CDX2 negative?

Yes. Most colorectal cancers are CDX2 positive, but a proportion are not. This does not overturn a diagnosis established through tissue examination and clinical workup. If you have a confirmed colorectal cancer diagnosis and your IHC panel shows CDX2 negative, ask your oncologist what additional significance this has for your individual assessment.

Why was CDX2 tested if they already found a tumour?

When a cancer is found in a secondary site — such as the liver or a lymph node — but the organ it started in is not yet known, IHC markers including CDX2 help identify the origin. This matters because treatment is guided by where the cancer began, not just where it was found. CDX2 positive in that setting helps point the investigation toward the GI tract.

Can I use the CDX2 result to understand what treatment I will have?

Not directly. CDX2 informs the diagnosis, and the diagnosis guides treatment — but one marker result does not determine a treatment plan. That decision belongs with your oncologist, who reads the full pathology report alongside your imaging, stage, and overall health. Bring your report to your next appointment and ask your oncologist to explain what each result contributed to the overall picture.

Full index

Browse all 701 biopsy topics

Every page in this section, grouped by the part of the journey it belongs to. Pick a group to see what is in it.

What Is a Biopsy?

What Is a Biopsy? Everything You Need to Know →

Types of Biopsy Compared

Which Biopsy Will You Have? Techniques Compared →

Preparing for a Biopsy

What to Expect on the Day of Your Biopsy →

Recovery and Aftercare

After a Biopsy: Recovery, Aftercare and Warning Signs →

Biopsy by Body Part

Biopsy by Body Part: What to Expect at Each Site →

Understanding Your Report

How to Read a Biopsy Report: Terms Explained →

IHC and Molecular Markers

IHC and Molecular Markers on a Biopsy: What They Mean →

Grading and Scoring Systems

Cytology & Prostate Scoring Systems Explained →

How Accurate Is a Biopsy?

How Accurate Is a Biopsy? Errors and Second Opinions →

If Your Result Is Benign

Your Biopsy Is Benign: What It Means and What Comes Next →

Call now Book free consultation