Tumor Diagnostics: Specialists and Information

The goal of tumor diagnostics is to investigate a suspected case of cancer and to determine the characteristics of a tumor more precisely. Characteristics such as

• size,
• shape, and
• extent 

of a tumor are decisive in choosing the form of treatment.

Using various methods, specialists look for metastases—that is, secondary tumors in lymph nodes or other tissues. If metastases are already present, the prognosis is poorer. Therefore, detecting the tumor as early as possible is crucial.

The process from the initial consultation to the final diagnosis varies depending on the type of cancer. Most patients visit their 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. During this, the patient describes their symptoms and medical history to date. This is followed by a referral for an imaging exam. At the same time, the doctor orders a blood test to check for so-called tumor markers. These are substances that can provide initial clues about the type of tumor. A biopsy is often necessary to confirm the diagnosis. During this procedure, a small piece of the tumor is removed using a needle or special equipment and examined under a microscope.

Oncologists compile all the findings and then determine the course of treatment.

Radiologists and Imaging Techniques

Imaging techniques play a major role in cancer diagnosis. These include

• conventional X-rays,
• simple ultrasound,
• fast CT,
• the more complex MRI, and
• specialized nuclear medicine examinations.

This field is the domain of radiologists and nuclear medicine specialists.

In an X-ray, the body is scanned with radiation, producing a two-dimensional grayscale image. This gives the radiologist an initial overview of the tumor’s location and size. For patients, this method is straightforward and minimally invasive.

Ultrasound imaging also provides a picture of the deeper layers of the body. Structures surrounded by bone—such as the brain—cannot be visualized using ultrasound. This method is therefore limited to certain types of cancer in soft tissues, such as the thyroid gland. However, it does not involve radiation exposure and is readily available almost everywhere.

Computed tomography (CT) is essentially a series of X-ray images superimposed on one another. This creates a three-dimensional image that shows the exact extent of the tumor. Radiation exposure is relatively high, so CT is used with caution in children or pregnant women.

In magnetic resonance imaging (MRI), alternating magnetic fields generate three-dimensional cross-sectional images of the body. This method provides excellent images of almost all regions of the body. Unlike CT, it does not require X-rays. However, the examination takes longer. Some patients with claustrophobia also find it stressful.

Imaging tests, 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 certain types of cancer. The combination of an imaging method and special radioactive contrast agents allows for the assessment of a tumor’s function and metabolism.

These examinations are particularly suitable for tumors and metastases in

• bones,
• the thyroid, and
• the brain.

Radioactivity often causes anxiety in patients, yet the radiation exposure is usually even lower than that of a CT scan.

Laboratory physicians examine the blood

A blood draw followed by laboratory analysis is always part of cancer diagnosis. This provides oncologists with valuable information about both the tumor itself and the patient’s overall condition.

So-called tumor markers are substances that appear in the blood in certain types of cancer. However, other diseases can sometimes cause these levels to rise as well. Elevated tumor markers therefore provide initial clues, but are not sufficient on their own for a definitive diagnosis. They are, however, well-suited for monitoring the course of the disease, as they are often the first to indicate a possible relapse.

Examples of specific tumor markers include

• carcinoembryonic antigen (CEA) for colorectal cancer,
• prostate-specific antigen (PSA) for prostate cancer, and
• alpha-fetoprotein (AFP) for liver tumors.

During the blood test, doctors also routinely determine

• the number of blood cells,
• liver and kidney function values, and
• numerous other parameters.

Pathologists examine tissue under a microscope

The final step in tumor diagnosis is often a biopsy. During this procedure, the doctor removes a tissue sample from the tumor and has it examined under a microscope by pathologists. This is the only way pathologists can determine with certainty whether the tumor is benign or malignant.

The biopsy procedure varies depending on the location and type of tumor. In most cases, the doctor removes a small amount of tumor tissue using a special needle under local anesthesia. For some types of cancer,

• punch biopsy devices,
• electric loops, or
• lasers

. To increase precision, doctors often work under visual guidance using ultrasound or X-rays. Thanks to the local anesthesia, patients do not feel any pain during the procedure. Severe bleeding or infections rarely occur after a biopsy, but the risk is low.

A malignant tumor invades surrounding tissue. This is referred to as invasive growth and significantly influences the prognosis. The appearance and degree of differentiation of the cells provide clues as to the exact type of cancer. These findings influence the subsequent selection of medications and other forms of therapy.

Special molecular biology methods make it possible to detect mutations in cancer cells. Mutations are genetic changes. These can, for example, allow malignant cells to grow unchecked and become resistant to medications. With this knowledge, treatment can be optimized.

Once imaging results, blood test findings, and molecular biological evidence have been evaluated, doctors from various specialties convene in a tumor board. This is the name given to the multidisciplinary conference consisting of

• radiologists,
• pathologists,
• oncologists, and
• surgeons

. There, the specialists discuss the next steps and select the most appropriate treatments on a case-by-case basis.

The attending physician explains the planned treatments, their benefits, and risks to the patient. Psychosocial support must also not be neglected in this difficult situation. Many hospitals therefore offer connections to support groups.