Colon cancer is a daunting diagnosis that affects nearly 150,000 Americans each year. While the cancer itself may not always present with physical symptoms in its early stages, it can be detected through routine blood work. Abnormal lab results are often the first indicators that something may be amiss in the body, and in the case of colon cancer, abnormalities in certain biomarkers are common.
In order to get a more accurate picture of how advanced the colon cancer is, doctors will often order a series of blood tests and imaging studies. One such test is the carcinoembryonic antigen (CEA) test, which measures the levels of CEA in the blood. This protein is typically found in very small amounts in the body, but elevated levels can indicate the presence of colon cancer.
Another potential lab abnormality that can indicate colon cancer is anemia. This occurs when there is a deficiency in red blood cells, which are responsible for oxygenating the body’s tissues. Colon cancer can cause internal bleeding that may not be visible to the naked eye; over time, this blood loss can lead to anemia. If a routine blood test shows a lower than normal hemoglobin or hematocrit level, further testing may be necessary to determine whether colon cancer is the cause.
Common Symptoms of Colon Cancer
Colon cancer is a type of cancer that begins in the large intestine (colon). Like many other cancers, it may not present symptoms in the early stages, making regular colonoscopies an essential screening tool for high-risk people. However, there are some common symptoms of colon cancer that should not be overlooked.
- Change in bowel habits: If there is a sudden and prolonged change in bowel movements, such as diarrhea or constipation for more than a few weeks without an apparent reason, it may be a sign of colon cancer.
- Blood in the stool: This is a classic symptom of colon cancer. Blood may be bright red or deep red and can be seen in the toilet or on the toilet paper. Still, bleeding may not always be noticeable as it may be microscopic.
- Abdominal pain/discomfort: One of the less common symptoms of colon cancer is persistent abdominal pain or discomfort that persists despite lifestyle changes, medication, stretching, and other treatments.
Abnormal Lab Results with Colon Cancer
Colon cancer can affect the lab results in different ways. The following abnormal lab results may suggest the presence of colon cancer in an individual:
Elevated Liver Enzymes: Colon cancer that has metastasized to the liver can cause elevated liver enzymes, as the liver is the organ that processes waste from the colon and other organs. Therefore, elevated liver enzymes may indicate cancer cells have reached the liver.
Abnormal Level of Tumor Markers: Tumor markers are proteins or other substances found in the blood, urine, or tissues of patients with cancer. Colon cancer can produce abnormal levels of tumor markers such as carcinoembryonic antigen (CEA), which might suggest the presence of a tumor in the colon. However, tumor markers can be elevated for reasons other than cancer, making them non-specific markers for cancer.
| Lab Test | Normal Range | Abnormal Result in Colon Cancer |
|---|---|---|
| CEA | 0 – 3 ng/mL | Elevated |
| Complete Blood Count (CBC) | Varying by sex and age | Low red blood cells count (anemia) caused by blood loss |
| Liver Function Test (LFT) | Varying by facility | Elevated liver enzymes (AST and ALT) |
If you are experiencing any of the symptoms of colon cancer or exhibit abnormal lab results and are at high risk of colon cancer, do not ignore them. It is important to talk to your doctor and get tested to prevent serious complications.
Blood tests for colon cancer
In addition to imaging tests and colonoscopies, blood tests can be conducted to help detect and diagnose colon cancer. Here are some of the blood tests that can be performed:
- CEA (carcinoembryonic antigen): This test measures the level of a protein called CEA in the blood. High levels of CEA can indicate the presence of colon cancer. However, CEA levels can also be elevated in other conditions such as inflammation. Therefore, this test is not always reliable in diagnosing colon cancer.
- Fecal occult blood test (FOBT): This test detects the presence of blood in the stool, which can be a sign of colon cancer. However, this test is not specific to colon cancer and can also give false positive results due to other conditions such as hemorrhoids.
- Complete blood count (CBC): This test measures the levels of various blood cells in the body, including white blood cells, red blood cells, and platelets. Abnormal levels of these cells can indicate the presence of colon cancer or other conditions such as anemia or infection.
It’s important to note that these blood tests are not enough to diagnose colon cancer on their own, and are typically used in conjunction with other diagnostic tools. Additionally, these tests are not foolproof and can sometimes give false positive or false negative results.
Imaging tests for colon cancer
Imaging tests are crucial in the detection and diagnosis of colon cancer. The following imaging tests provide important information to doctors and healthcare providers:
- CT scan: A CT scan of the abdomen and pelvis is commonly used to detect and stage colon cancer. A CT scan can provide detailed images of the colon, lymph nodes, and other organs in the abdomen and pelvis.
- MRI: An MRI of the abdomen and pelvis is another imaging test used to detect and stage colon cancer. It can provide detailed images of the colon, lymph nodes, and other organs in the abdomen and pelvis. An MRI may also be used to detect cancer that has spread to the liver.
- PET scan: A PET scan is a nuclear medicine imaging test that can detect cancer cells in the body. It is often used in conjunction with a CT scan to provide more detailed information about the location and extent of cancer in the colon and potential metastases to other parts of the body.
It’s important to note that while imaging tests can provide important information about colon cancer, they are not the only means of detecting the disease. Other diagnostic methods include colonoscopy and biopsy.
In addition to providing important information about colon cancer, imaging tests can also be used to monitor the effectiveness of treatment and to detect any recurrence of the disease. Patients with colon cancer will typically undergo imaging tests at various points during treatment and follow-up care.
| Imaging Test | Description |
|---|---|
| CT Scan | A specialized X-ray that provides detailed images of the colon, lymph nodes, and other organs in the abdomen and pelvis. |
| MRI | A non-invasive procedure that uses powerful magnets and radio waves to create detailed images of the colon, lymph nodes, and other organs in the abdomen and pelvis. |
| PET Scan | A nuclear medicine imaging test that can detect cancer cells in the body. It is often used in conjunction with a CT scan to provide more detailed information about the location and extent of colon cancer. |
Overall, imaging tests play a crucial role in the detection, diagnosis, and monitoring of patients with colon cancer. Patients should discuss with their healthcare provider which imaging tests are best suited for their specific needs and circumstances.
Biopsy and histology for colon cancer
In order to diagnose colon cancer, a biopsy of the colon tissue is taken to check for abnormalities. A biopsy is the removal of a small piece of tissue for examination under a microscope, and it is a common procedure used to diagnose cancer. Once the biopsy is taken, the tissue sample is sent to a laboratory for histological examination, which refers to the study of the cells and tissues under a microscope by a trained pathologist.
- During histological examination, the pathologist looks for abnormal tissue growth, particularly cancerous growth, and grades the cancer based on how much the cells have changed from their normal appearance. This grading is known as the cancer’s histologic grade.
- The pathologist will also look for other characteristics of the cancer cells that can help determine the cancer’s stage, such as size, depth of invasion, and lymph node involvement. These factors play an important role in determining the best treatment options for the patient.
- In some cases, genetic testing may also be done on the biopsy sample to identify any specific genetic mutations that may be contributing to the cancer’s growth. This information can help determine the cancer’s prognosis and identify the most effective treatment options.
Once the biopsy and histologic examination are complete, the pathologist will provide a report detailing their findings. This report is a critical component of the patient’s treatment plan, as it provides important information about the cancer’s characteristics and guides the selection of appropriate treatment options.
Here is an example of histological grading for colon cancer:
| Histologic Grade | Description |
|---|---|
| Grade 1 | Cancer cells look almost normal, and grow slowly. |
| Grade 2 | Cancer cells look slightly abnormal, and may grow more quickly. |
| Grade 3 | Cancer cells appear very abnormal, and may grow and spread more quickly. |
| Grade 4 | Cancer cells look highly abnormal and are growing and spreading rapidly. |
Understanding the histologic grade of the cancer is important as it can help predict how aggressive the cancer is likely to be and determine the best course of treatment. For example, low-grade cancer may only require surgery or less intensive treatments, whereas high-grade cancer may require more aggressive treatments like chemotherapy or radiation therapy.
Staging of colon cancer
Staging of colon cancer is an important part of the diagnostic process. It helps doctors to understand how far the cancer has progressed and what the appropriate treatment options are. The process of staging involves determining the size and location of the tumor, whether it has spread to nearby lymph nodes or other organs, and how aggressive it is.
- Stage 0: This is the earliest stage of colon cancer. The cancerous cells are only in the innermost lining of the colon and have not spread to other tissues.
- Stage I: In this stage, the cancer has grown slightly into the wall of the colon but has not yet spread to nearby lymph nodes.
- Stage II: The cancer has grown into or through the wall of the colon but has not yet spread to nearby lymph nodes.
- Stage III: The cancer has spread to nearby lymph nodes but has not yet spread to other organs.
- Stage IV: This is the most advanced stage of colon cancer. The cancer has spread to other organs such as the liver or lungs.
Once the cancer has been staged, doctors can determine the appropriate treatment plan. Treatment options may include surgery, chemotherapy, radiation therapy or a combination of these approaches. The earlier the cancer is detected, the better the chances of successful treatment. It is important to undergo regular screening for colon cancer to catch the disease in its earliest stages.
Below is a table that further explains the characteristics of each stage of colon cancer:
| Stage | Description | Treatment Option |
|---|---|---|
| 0 | Cancer cells only in the innermost lining of the colon | Surgery |
| I | Cancer has grown into the wall of the colon but has not spread to nearby lymph nodes | Surgery |
| II | Cancer has grown through the wall of the colon but has not spread to nearby lymph nodes | Surgery |
| III | Cancer has spread to nearby lymph nodes but has not spread to other organs | Surgery, chemotherapy, radiation therapy |
| IV | Cancer has spread to other organs such as the liver or lungs | Chemotherapy, radiation therapy, surgery |
As with any cancer, early detection of colon cancer is critical. By staying informed, getting screened regularly and having open communication with your physician, you can increase your chances of surviving colon cancer.
Molecular Testing for Colon Cancer
Advancements in technology and research have led to more targeted treatment options for colon cancer. Molecular testing is the study of genetic and molecular changes in cancer cells that can help determine the best course of treatment for an individual patient. Here are some examples of molecular tests used in colon cancer:
- BRAF gene testing: The BRAF gene mutation is present in about 10% of colon cancers and can affect treatment options. If present, patients may benefit from certain targeted therapies.
- Microsatellite instability testing: This test assesses the instability of the DNA present in colon cancer cells and can help predict response to immunotherapy.
- KRAS gene testing: The KRAS gene mutation is found in approximately 40% of colon cancers and can determine whether certain drugs will be effective in treating the cancer.
Molecular testing is becoming increasingly important in tailoring treatment plans for colon cancer patients. As more research is conducted, additional molecular tests may be developed to help identify the best options for each individual patient.
Here is a table summarizing some of the molecular testing options for colon cancer:
| Test Type | Description | Uses |
|---|---|---|
| BRAF gene testing | Tests for the presence of the BRAF gene mutation | Determines if certain targeted therapies will be effective |
| Microsatellite instability testing | Assesses the instability of the DNA in colon cancer cells | Predicts response to immunotherapy |
| KRAS gene testing | Tests for the presence of the KRAS gene mutation | Determines if certain drugs will be effective |
Consult with your healthcare provider to determine if molecular testing is appropriate for your individual case.
Treatment options for colon cancer
After a diagnosis of colon cancer, treatment options will depend on the stage and location of the cancer, as well as the patient’s overall health and preferences. The following are some common treatment options for colon cancer.
- Surgery: Surgery is the primary treatment for early-stage colon cancer, and it involves removing the cancerous portion of the colon. In advanced cases, surgery may also involve the removal of nearby lymph nodes or other affected organs.
- Chemotherapy: Chemotherapy involves using drugs to kill cancer cells, which may be administered before or after surgery. It can also be used to relieve symptoms in advanced cases of colon cancer.
- Radiation therapy: Radiation therapy uses high-energy radiation to kill cancer cells and may be used in combination with chemotherapy or surgery.
There are also promising new treatments for colon cancer that are currently being studied, including:
- Immunotherapy: Immunotherapy is a type of cancer treatment that uses the patient’s own immune system to fight cancer. It works by stimulating the immune system to recognize and attack cancer cells.
- Targeted therapy: Targeted therapy involves using drugs that target specific genes or proteins in cancer cells. This type of treatment can be more effective and have fewer side effects than traditional chemotherapy.
- Gene therapy: Gene therapy is a relatively new approach to cancer treatment that involves altering the genes in cancer cells to make them more susceptible to other treatments.
Colon cancer biomarkers
Biomarkers are molecules found in the blood, urine, or tissue that can indicate the presence of cancer. In colon cancer, there are several biomarkers that can be used to help diagnose and monitor the disease. These include:
| Biomarker | Description |
|---|---|
| Carcinoembryonic antigen (CEA) | A protein that is often elevated in the blood of people with colon cancer. CEA levels can be used to monitor the effectiveness of treatment and to check for cancer recurrence. |
| Mutant KRAS | A genetic mutation that is found in about half of all colon cancers. Testing for mutant KRAS can help determine whether certain treatments, such as targeted therapy, may be effective. |
| Microsatellite instability (MSI) | A type of genetic irregularity that is found in about 15% of colon cancers. MSI testing can help determine the best course of treatment and may be used to identify people with a higher risk of developing colon cancer. |
While biomarkers can be helpful in diagnosing and monitoring colon cancer, they are not foolproof and should always be used in combination with other diagnostic methods.
Frequently Asked Questions: What Labs are Abnormal with Colon Cancer?
Q: What kind of blood tests are done for colon cancer?
A: The most common tests for colon cancer are CBC (complete blood count), liver function tests, and CEA (carcinoembryonic antigen) levels.
Q: What abnormal findings can a CBC show in colon cancer?
A: CBC can show low red blood cells (anemia), low white blood cells (leukopenia), and low platelets (thrombocytopenia) patterns associated with colon cancer.
Q: Why are liver function tests done in colon cancer?
A: Liver function tests (LFTs) help to detect abnormalities in the liver caused by colon cancer that spread to the liver or due to treatment side effects.
Q: What abnormalities can LFTs indicate in colon cancer?
A: LFTs can show elevated levels of liver enzymes, such as ALT (alanine transaminase), AST (aspartate transaminase), and ALP (alkaline phosphatase), elevated bilirubin levels, and elevated albumin levels.
Q: What is CEA and why is it measured?
A: CEA is a protein found in the blood that is used as a tumor marker for colon cancer. It is measured before and after treatment to monitor disease progression.
Q: What does an elevated CEA level indicate in colon cancer?
A: An elevated CEA level can indicate that colon cancer cells are still present in the body, cancer has recurred, or that treatment is not working well.
Q: Can labs be used alone to diagnose colon cancer?
A: No, labs cannot diagnose colon cancer alone. They are used as adjunctive procedures to determine the extent and effects of the disease on the body.
Closing Thoughts
Thanks for taking the time to read about what labs are abnormal with colon cancer. Remember, early detection and treatment are crucial for improving outcomes. If you have concerns about your health, speak with your doctor or a specialist. Please visit us again soon for more informative articles.