The aim of tumor diagnostics is to investigate a suspected cancer and to determine the characteristics of a tumor more precisely. Characteristics such as
of a tumor are decisive for the choice of therapy.
Specialists use various methods to search for metastases, i.e. metastases in lymph nodes or other tissues. If metastases are already present, the prognosis is worse. It is therefore crucial to detect the tumor as early as possible.
The process from initial consultation to final diagnosis varies depending on the type of cancer. Patients usually come to the doctor because they have specific symptoms and fear they may have cancer. Sometimes a routine examination also leads to the discovery of a tumor.
The diagnostic process begins with a medical history. The patient describes the symptoms and their previous medical history. This is followed by a referral for an imaging examination. At the same time, the doctor will arrange for a blood test to look for tumor markers. These are substances that can give an initial indication of the type of tumor. A biopsy is often necessary to confirm the diagnosis. A small piece of the tumor is removed using a needle or special equipment and examined under a microscope.
Oncologists collect all the findings and then determine the treatment.
Radiologists and imaging techniques
Imaging procedures play a major role in cancer diagnostics. These include
- the classic X-ray,
- simple ultrasound,
- the fast CT,
- the more complex MRI and
- special nuclear medicine examinations.
This field is the domain of radiologists and nuclear medicine specialists.
X-rays are used to scan the body and produce a two-dimensional image in grayscale. This gives the radiologist an initial overview of the location and size of the tumor. This method is uncomplicated and less stressful for patients.
Fluoroscopy with ultrasound waves also provides an image of the deeper layers of the body. Structures surrounded by bone, such as the brain, cannot be imaged using ultrasound. This method is therefore limited to certain types of cancer in soft tissue such as the thyroid gland. However, it does not involve radiation exposure and is quickly available almost everywhere.
Computed tomography (CT) is basically a series of X-ray images that are superimposed on each other. This produces a three-dimensional image that shows the exact extent of the tumor. The radiation exposure is relatively high, which is why CT is only used with caution in children or pregnant women.
In magnetic resonance imaging (MRI ), alternating magnetic fields produce three-dimensional cross-sectional images of the body. This method provides excellent images of almost all regions of the body. In contrast to CT, no X-rays are required here. However, the examination takes longer. Some patients with claustrophobia also find it stressful.
Imaging examinations, such as MRI and CT, are among the most important procedures in tumor diagnostics © Gorodenkoff | AdobeStock
Less well known are nuclear medicine procedures, which are highly informative for some types of cancer. The combination of an imaging method and special radioactive contrast agents makes it possible to assess the function and metabolism of a tumor.
These examinations are particularly suitable for tumors and metastases in
- bones,
- thyroid gland and
- brain.
Radioactivity often arouses fears in patients, but the radiation exposure is usually even lower than with computer tomography.
Laboratory physicians examine the blood
A blood sample with subsequent analysis in the laboratory is always part of cancer diagnostics. This provides oncologists with valuable information about both the tumor itself and the patient's general condition.
Tumor markers are substances that occur in the blood in certain cancers. However, sometimes other diseases also lead to an increase in these values. Elevated tumor markers therefore provide initial indications, but are not sufficient on their own for a definitive diagnosis. However, they are well suited for monitoring the course of the disease, as they are often the first to provide information about a possible relapse.
Examples of specific tumor markers are
During the blood test, the doctors also routinely determine
- the number of blood cells,
- liver and kidney values and
- numerous other parameters.
Pathologists examine tissue microscopically
The final step in tumor diagnostics is often a biopsy. The doctor takes a tissue sample from the tumor and has it examined microscopically by pathologists. Only in this way can pathologists determine with certainty whether the tumor is benign or malignant.
The biopsy procedure differs depending on the location and type of tumor. In most cases, the doctor removes some tumor tissue with a special needle under local anesthesia. For some types of cancer, the doctor also uses
- punching devices,
- electric snares or
- lasers
are also used. To increase precision, doctors often work under visual control using ultrasound or X-rays. Due to the local anesthetic, patients do not feel any pain during the procedure. Major bleeding or infections rarely occur after a biopsy, but the risk is low.
A malignant tumor grows into surrounding tissue. This is known as invasive growth and significantly influences the prognosis. The appearance and degree of maturity of the cells provide clues as to the exact type of cancer. These findings influence the subsequent selection of drugs and other forms of therapy.
Special molecular biological methods make it possible to detect mutations in cancer cells. Mutations are genetic changes. As a result, malignant cells can, for example, maintain unhindered growth and resistance to drugs. With this knowledge, treatment can be optimized.
Once imaging, blood findings and molecular biological evidence have been evaluated, doctors from various disciplines meet in a tumor board. This is the name of the specialist conference, which consists of
surgeons. The specialist staff will discuss the next steps and select suitable therapies on an individual basis.
The attending physician informs the patient about the planned treatments, their chances and risks. Psychosocial support should also not be neglected in this difficult situation. Many hospitals therefore offer contact with self-help groups.
