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The importance of tumor markers in clinical practice
Tumor markers — are specific biological substances that are produced in the body in response to the development of the tumor process or are secreted directly by the malignant cells themselves. Their determination is of important clinical importance at various stages of diagnosis, treatment, and monitoring the effectiveness of therapy of malignant neoplasms.
What are tumor markers and how do they work?
Tumor markers can be proteins, enzymes, hormones, or metabolic products. Normally, they are either not detected in the blood at all or are present in very small concentrations. In oncological processes, their levels often increase, making them a valuable diagnostic and prognostic tool.
Clinical problems solved with the help of tumor markers
Screening and early diagnosis (e.g. PSA for prostate, AFP for liver cancer)
Differential diagnosis in difficult cases
Predicting the course of the disease
Monitoring treatment effectiveness (decreased levels after surgery or chemotherapy)
Detection of relapses (regular follow-up after remission)
The most common tumor markers and their clinical significance
| Tumor marker | Application area | Comment |
|---|---|---|
| PSA | Prostate cancer | Used for screening and monitoring |
| CA 125 | Ovarian cancer | Also increases with endometriosis |
| AFP | Liver cancer, teratomas | Also determined during pregnancy |
| CEA | Colorectal cancer | Susceptible to relapse |
| CA 19-9 | Pancreatic cancer | May be elevated in pancreatitis |
| HE4 | Ovarian cancer | Used with CA 125 in the ROMA algorithm |
Advantages and limitations of using tumor markers
Advantages:
High sensitivity for relapse monitoring
Possibility of non-invasive testing (blood, urine)
Relative speed of obtaining results
Limitation:
Low specificity: increase is possible in benign processes
Low efficiency for primary diagnosis without clinical manifestations
False positive results: possible with infections, pregnancy, inflammation
Current trends in the use of tumor markers
In clinical practice, there is growing interest in tumor marker panels, rather than single indicators. This increases the accuracy of diagnosis. For example, a combination of CA 125 and HE4 is used to assess the risk of ovarian cancer (ROMA index). In the future, increasingly important liquid biopsies, which allow the detection of circulating tumor DNA in the blood, is another step towards personalized oncology.
Target audience of the article
The material will be useful:
general practitioners and oncologists
patients with a family history of cancer
people after cancer treatment who are under monitoring
laboratory medicine specialists
The use of tumor markers in the clinic is of great importance, but only in the context of the complete clinical picture. No tumor marker is absolutely specific or sufficient for diagnosis. Comprehensive assessment together with instrumental methods is the basis of effective oncological diagnostics.
