The hunt to find the cause and diagnosis has been a topic of discussion and research in the medical industry for centuries. In an ancient Egyptian papyrus, breast cancer was discriminated from mastitis for the first time, marking the first recorded attempt to identify tumor markers. In the current era, studies show that diagnostic tests can save lives by diagnosing some cancers early. One screening test that can be used for early detection is tumor marking of cancers. You may be confused about what to do after learning about markers for the first time. To get you started, here is some information and advice.
What Are Tumor Markers?
A tumor marker is a protein, genetic fragment, or other molecule that indicates a tumor’s existence. In some patients, their cancer cells generate tumor markers. They are mainly proteins generated by cancer cells, many of which may be identified in the blood. The body may produce the marker in response to cancer cells in certain individuals. In cancers, these tumor markers are higher in concentration than normal levels. The tumor itself may produce these chemicals used as diagnostic indicators. There are two primary types of tumor markers:
- Tumor tissue (or cell) markers are detected within the actual tumors themselves, generally in a tumor biopsy sample.
- Some people with cancer have circulating tumor markers (CTC)in their blood, urine, feces, or other body fluids. A high concentration of circulating tumor markers may indicate the existence of malignancy. To detect cancer, circulating tumor markers are typically paired with the findings of additional procedures, such as biopsies or imaging.
Numerous tumor markers are now in use; these markers can be categorized according to their function, detection method, or the kind of material utilized for analysis. (1)(2). Most tumor markers are molecules produced by cancer cells or other cells in reaction to the existence of a tumor and can be discovered in a slice of the tumor (biopsy), the patient’s bodily fluids, or feces. These substances consist of:
- Antigens \antibodies
- Different proteins and complexes
- Hormones
- Tumor tissue (biopsy)
- Proliferating cancer cells (liquid biopsy)
Since DNA contains the code that dictates which proteins a cell will generate, scientists are researching techniques to detect DNA. Even in the earliest stages of many illnesses, cancer cells can break out from the tissue where they originated and be discovered in the blood and other bodily fluids. This unique approach to tumor marker testing may provide more accurate and useful data for screening, early detection, monitoring, and treatment planning since it evaluates the source (DNA) rather than the effect (protein).
Another new type of screening has been done in very recent research of a compact, flexible gadget, termed the “Flexible Autonomous Sensor for Measuring Tumors (FAST)” which may be applied to the tumor location a patch. Built-in sensors track the expansion or contraction of tumors. FAST promises to increase the rate at which tumors may be assessed, which has significance for cancer research and therapy.
Tumor Marker Testing:
Tumor marker testing is often performed to better understand cancer and its treatment options. In large-scale studies of screening the general population, no tumor marker has been shown to improve survival. However, tumor markers can be extremely helpful in identifying illness and monitoring response to treatments. When checking for disease recurrence, tumor marker levels should be checked only if doing so might positively impact patient care.
Why, when, and how frequently these tests are administered vary substantially amongst individuals. Infrequently, they aid in detecting a specific type of cancer in high-risk individuals before the onset of symptoms. However, physicians primarily employ tumor marker testing to:
- Screening: a selective handful can be utilized to screen patients with a significant family history of cancer or cancer risk factors. Your health, medical history, and any symptoms you’re experiencing will all play a role in determining which tests you undergo. What are other examinations required for the early detection of cancers? We have got it covered in a dedicated article. Read Here.
- Diagnosing: Tumor markers may be utilized in symptomatic patients to diagnose cancer and differentiate it from other disorders. Also, selecting which treatment or combination of therapies will work best for a given form of cancer.
- Staging: Tumor marker elevations can help determine if and how far cancer has spread to different tissues and organs.
- Severity: Estimate the expected degree of cancer’s malignant potential.
- Choice of Treatment: A few tumor markers give information on which potential cancer therapies may be beneficial and figure out how effectively a therapy works. This is an expanding field of study.
- Monitoring of Treatment: For advanced tumors, tumor markers can be used to track improvement over time. The therapy is successful if the marker level decreases; else, further intervention may be required. The data must still be used with care. For example, Carcinoembryonic antigen (CEA) monitors bowel cancer. However, not all patients have high levels.
- Prognosis and recovery: Cancer tumor biomarkers aid in prognosis, therapy planning, and a person’s probability of recovery.
- Remission: Cancer recurrence detection is a major use of tumor markers. It helps to predict how probable cancer will return after treatments and identify if it does.
Consult your medical professional about your case’s advantages and disadvantages of blood marker testing.
Types of Tumor Markers.
Rapid medical progress has led to the discovery of numerous markers, and more are being discovered daily. These markers are crucial not only for the early detection of tumors but also for analyzing tumor types, selecting appropriate treatments, and monitoring cancer survivorship. We Discuss region wise tumor markers,
Breast Cancer:
One of the most prevalent cancers afflicting women worldwide is breast cancer. According to the National Cancer Institute, there will be an estimated 281,550 new breast cancer cases in the United States in 2021. Researchers have not identified a tumor marker that aids in detecting or screening breast cancer in its early stages. Some of the tumor markers and their associated normal and high-test range result ranges are listed in the table below.
| Marker test | Normal | High |
| CA 15-3 | Less than 30 U/mL | 30 U/mL or higher |
| CA 27-29 | Less than 38 U/mL | 38 U/mL or higher |
| CA125 | Less than 35 U/mL | Greater than 35 U/mL |
| CEA | Less than 2.5 ng/mL | Extensive disease: Greater than 10 ng/mL Metastatic disease: Greater than 20 ng/mL |
| CTCs | N/A | Greater than 5 CTCs per 7.5 mL of blood |
Patients with advanced disease benefit the most from using these markers to track their therapy progress. Normal blood levels fall when cancer treatment is effective and rise when the disease worsens.
Liver Cancer:
When identifying individuals with hepatocellular carcinoma, serum alpha-fetoprotein (AFP) is the gold standard because of its capacity to predict outcomes.
| Tumor marker | Elevated result |
| Alpha-fetoprotein (AFP) | Â more than 15 ng/ml |
Lung Cancer:
The marker which is specific for lung cancer is CEA. The National Cancer Institute states that a CEA level of 2.5 ng/mL or lower is considered normal, albeit this varies with each test. Levels of CEA between 10 and 20 ng/mL indicate advanced illness and metastasis, respectively.
| Tumor marker | Elevated result |
Carcinoembryonic antigen
|
 more than 3 ng/ml |
Pancreatic Cancer:
Pancreatic cancer patients’ blood contains tumor biomarkers. These indicators can assist in identifying pancreatic cancer and show therapy efficacy. Tumor markers are used in diagnosing pancreatic cancer, although they aren’t always reliable. (1) (2) As an example, some individuals with pancreatic cancer may not have abnormally high levels of CA19-9 or CEA. According to some studies, genetic differences may affect tumor marker levels for pancreatic cancer.
| Tumor marker | Typical values | High values |
| CA19-9 | 0 to 37 units per milliliter | greater than 37 units per milliliter |
| CEA | less than or equal to 3 micrograms per liter (Smoking can increase this value to less than 5 micrograms per liter) | higher than 5 micrograms per liter |
Among pancreatic cancer markers, CA 19-9 is the most informative. Increased blood concentrations of CA 19-9 are characteristic of pancreatic cancer individuals. If the level is high, the illness has likely spread to a wider area.
Cervical Cancer:
Tumor markers unique to cervical cancer have been found through several different scientific research. Cervical cancer is not uniquely marked by these indicators, although they can aid in diagnosis anyway. The following are frequent tumor markers for cervical cancer:
| Tumor marker | Elevated result |
| CA 125 | more than 35 units/mL |
| CEA | more than 5 ng/mL |
| CA 19-9 | more than 39 units/mL |
 Prostate Cancer:
The PSA blood test is often used to screen healthy males for prostate cancer. It is also one of the first tests for men experiencing possible prostate cancer symptoms. The test can interpret the following result. Prostate-specific antigen is the gold standard for diagnosing prostate cancer
| Tumor marker | Elevated result |
| PSA (Prostate-specific antigen) | levels more than 15 ng/ml are indicative |
The earlier and less sensitive test known as prostatic acid phosphatase (PAP) is no longer widely utilized.
These markers can be tracked during therapy if they are elevated following a cancer diagnosis. Remember that increased levels do not always indicate the presence or recurrence of cancer. They might simply indicate the need for a follow-up appointment or more diagnostics. A doctor will go through the results with you as soon as they are in.
The table below summarizes tumor markers that may have been discovered, their sample selection, and what other causes can raise it.
| Tumor Markers | Cancers | Other Causes of Elevation | Uses | Sample |
| cell lung cancer, | – | To help determine treatment and prognosis | Tissue | |
| Liver, ovarian, and testicular | Pregnancy/ Hepatitis | facilitate diagnosis, monitor therapy, and determine prognosis. | Blood | |
| B-cell lymphoma | – | Diagnose, evaluate therapy, and monitor for recurrence | Blood, bone marrow, or tumor tissue | |
| Bladder cancer and cancer of the kidney or ureter | – | Diagnose and monitor the recurrence of bladder cancer. | Urine | |
| Ovarian and breast cancers | It can also be elevated in the prostate and pancreas and possibly in bone | To help determine treatment | Blood/ Tissue | |
| breast cancer, lung, and ovarian cancers | Raised levels in benign breast conditions | Diagnose a disease, record treatment, and determine the prognosis. | Blood | |
| Pancreatic and, in rare cases, bowel and bile duct, | increased in inflammatory bowel disease, gallstones and pancreatitis. | Diagnose a disease, record treatment, and determine the prognosis. | Blood | |
| bile duct, gastric cancer | ||||
| Ovarian cancer, cervical cancer | Elevated endometriosis, gallstones, | facilitates diagnosis, monitor therapy, and determines prognosis. | Blood | |
| Medullary thyroid carcinoma (MTC) and C-cell hyperplasia | Facilitate diagnosis, monitor therapy, and determine prognosis. | Blood | ||
| Cancers of the colon, pancreas, lungs, breast, ovaries, and medullary thyroid | elevated in hepatitis, COPD, colitis, pancreatitis, and cigarette smokers. | It diagnoses cancer, classifies it into stages, determines a prognosis, and tracks its progress during therapy and any recurrence. | Blood | |
| Non-Hodgkin lymphoma | – | Helps to determine the treatment protocol | Blood | |
| Neuroendocrine tumors | – | Assists in diagnosis, monitoring therapy and detects recurrence. | Blood | |
| Breast | Increased in hormone-dependent cancer | Determines prognosis, advice therapy | Tissue | |
| A gastrin-producing tumor (gastrinoma) | To help in diagnosis, to monitor the effectiveness of treatment, and to detect recurrence | Blood | ||
| Breast, gastric, esophageal, and stomach | – | Used for prognosis and treatment management. | Tissue | |
| testicular | High during pregnancy, testicular dysfunction | Help diagnose, monitor treatment, and determine recurrence | Urine/ Blood | |
| Metastatic prostate cancer | To help in diagnosing poorly differentiated carcinomas | Blood | ||
| Prostate | Also elevated in benign prostatic hyperplasia (BPH) and prostatitis and aging | screening, assisting in diagnosis, tracking therapy, and detecting recurrence. | Blood | |
| T-cell lymphoma | Also identifies changes in T-cell genes. | Assists in diagnosis, supervise treatment, and detects recurrence. | Bone marrow/ tissue/ body fluid/ blood | |
| Thyroid | Used after thyroidectomy to monitor therapy | Monitors therapy and recurrence of disease | Blood |
Tumor marker testing may not be a viable choice for many cancer patients since so few of them have identifiable tumors. While many tumor markers are offered and have been proven clinically beneficial, others are available but not requested frequently since they have been discovered to be less sensitive and/or specific. Considering ongoing research, and as the field continues to advance, it is expected that additional tumor markers with better effectiveness may emerge on the market in the future, eventually replacing less beneficial ones. (1) (2)
How These Tests are Performed:
Suppose you are receiving a tumor marker test as a health screening. In that case, your physician will first inquire about your family medical history to determine whether you have an inherited risk for certain forms of cancer. Your doctor may perform blood tests for cancer/tumor markers to detect cancerous activity in the body.
They are often done in a clinical or diagnostic setting.
No special preparation is normally required for such tests. They will then obtain a body fluid sample, usually blood or urine sample, and send it to designated laboratories where tests for various diagnostic markers will be conducted. It may be necessary to repeat a test more than once to keep up with fluctuating tumor marker levels. These tests are quite safe and provide minimal danger.
If a tumor marker test is being performed to assess the efficacy of therapy, your test results may be compared to those obtained before treatment.
- If tumor marker levels fall or return to normal, the therapy may be beneficial, especially if levels were high before treatment.
- A spike in tumor marker concentrations may mean the cancer isn’t responding to treatment, is growing, or has returned (recurred). A small rise may not be noteworthy.
- Chemotherapy raises tumor marker levels temporarily. This happens because chemotherapy causes cancer cells to die quickly and release large amounts of the tumor marker.
Having tumor markers in your body is not sufficient for a cancer diagnosis. Additional testing is likely necessary to determine the severity of any potential malignancy or recurrence.
American Society of Clinical Oncology (ASCO) guidelines say that standard use of a marker in routine clinical practice should only be recommended if the marker reliably helps the doctor make better clinical decisions, such as by increasing survival, improving quality of life, or lowering costs.
The detection of tumor biomarkers may be a component of your treatment approach. A physician may repeat the same tumor marker tests several months following therapy. Based on the latest test findings, they will discuss the effectiveness of your therapy and their plans with you.
Limitations:
However, there are certain drawbacks to tumor marker testing, notwithstanding their potential value:
- It’s not only cancer that can cause an increase in tumor markers; many other ailments and disorders can do the same.
- There are tumor markers unique to some cancers and others observed in many different cancers.
- Elevated levels of the relevant tumor marker are not always present in patients with cancer.
- Unfortunately, not all cancers have been linked to specific tumor markers.
- In addition, the levels of circulating tumor markers might be affected by unrelated disorders and diseases, such as pregnancy, menopause, inflammation, or the removal of organs or tissues by surgery in the past.
It’s important for loved ones of cancer patients to know that caregiver stress can compromise their capacity to give their loved one the best care possible. When a loved one is diagnosed with terminal cancer, palliative care can help you provide them with the best quality of life possible. Learn more about how to deal with this condition in this article.
Tumor markers are a useful tool for tracking the progression of a disease, predicting a patient’s prognosis, and guiding treatment decisions since they are noninvasive, inexpensive, and easy to get and help in diagnosis and therapy. Researchers are trying to learn as much as they can about each cancer. This is why tumor marker testing may be suggested at different points in the diagnostic, therapeutic, and follow-up processes. Elevated tumor markers may indicate cancer but aren’t enough to diagnose it. Tumor marker data are always linked with imaging (MRI, mammography) and biopsies. Combining several tests helps lessen the chance of false negative or false positive findings.
