Renal cell carcinoma tumor markers: how modern medicine recognizes kidney cancer in the early stages

Kidney cancer is one of the most insidious oncological diseases, which often develops asymptomatically. In most cases, it is detected by chance - during an ultrasound or CT scan, prescribed for other reasons. But what if there was a method of detecting the disease even before the appearance of clinical signs? Tumor markers - biological indicators that signal the development of a malignant process even at an early stage - could be such a tool.

Tumor markers are particularly important in the diagnosis of renal cell carcinoma (RCC), the most common type of kidney cancer in adults. What do these markers «tell» you? How and when should they be tested? And can they change treatment tactics?

What is worth knowing about renal cell carcinoma?

Renal cell carcinoma accounts for about 85–90% of all kidney cancers. It originates from the epithelial cells of the proximal tubules of the nephron. Risk factors for its development include:

• smoking

• hypertension

• adiposity

• long-term dialysis therapy

• hereditary syndromes (e.g., von Hippel-Lindau syndrome)

Unfortunately, a characteristic feature of this type of cancer is the absence of symptoms in the early stages. That is why it is important to have methods that help detect the disease before its clinical manifestations.

What are tumor markers and why are they important in NCC?

Tumor markers — are substances (proteins, enzymes, receptors) that are produced by tumor cells or released by the body in response to the presence of a malignant neoplasm. In the case of NCC, tumor markers are not a universal tool for diagnosis, but they are increasingly used for the following purposes:

• clarification of the nature of the detected neoplasm

• assessment of tumor activity

• monitoring treatment effectiveness

• detection of recurrences after surgery

The most promising tumor markers for renal cell carcinoma

Among the many potential biomarkers, researchers have identified a few that have real clinical significance.

1. Carbonic Anhydrase IX (CA IX)
   One of the most studied proteins associated with hypoxia in tumor cells. Its expression is highly characteristic of renal cell carcinoma, especially in the presence of VHL gene mutations. CA IX has both diagnostic and prognostic value.

2. VEGF (vascular endothelial growth factor)
   The role of VEGF in angiogenesis (the formation of new blood vessels) is well known. NCC tumors actively stimulate this process, so VEGF serves not only as a marker of aggressiveness but also as a target for targeted therapy.

3. HIF-1α (hypoxia-dependent transcription factor)
   Under conditions of reduced oxygen supply, tumor cells activate HIF-1α, which triggers survival mechanisms, in particular stimulating the production of VEGF and CA IX.

4. Neuron-specific enolase (NSE)
   Although this marker is more characteristic of neuroendocrine tumors, its level is also elevated in some patients with NCC.

5. Tissue markers (CD10, RCC marker)
   Determined immunohistochemically during biopsy. They confirm the cell origin and type of carcinoma. They are not serum markers, but are important for the final diagnosis.

Comparative table of the main tumor markers of NCC

When are tumor markers really needed?

It is not advisable to determine tumor markers for everyone at once. They are used:

• with questionable ultrasound findings

• before or after surgery (to assess residual tumor)

• in dynamics - for monitoring relapse

• during targeted or immunotherapy - to assess response

Also, CA IX and VEGF testing can help in choosing a personalized treatment plan.

Why is it important to consider dynamics, not just the result of a single analysis?

The level of tumor markers varies depending on the phase of the disease, the state of the immune system, and the presence of concomitant pathologies. Therefore, a one-time increase in the marker is not a sentence. However, a gradual increase, even within normal limits, is already a reason for caution.

In what cases are tumor markers not informative?

Tumor markers do not replace instrumental methods - CT, MRI, ultrasound. They should not be used as screening without clinical indications. A low level of a marker does not guarantee the absence of a tumor, especially at an early stage or with slow growth of the neoplasm.

Do tumor markers influence the choice of therapy?

Yes. For example, patients with high VEGF levels respond better to treatment with angiogenesis inhibitors (sunitinib, axitinib). And high CA IX expression is associated with a better prognosis with immunotherapy. Knowledge of the molecular profile of the tumor helps to choose an effective combination of drugs.

Current trends: genetic markers and liquid biopsy

The scientific community is actively investigating circulating tumor DNA as a source of new tumor markers. This approach is called liquid biopsy and is already beginning to be used in large oncology centers.

Also promising are:

• MicroRNAs (miRNAs) that alter gene expression in tumors

• Metabolic profiles of blood plasma

• Exosomes are vesicles containing proteins and tumor DNA.

Tumor markers for renal cell carcinoma are not a magic wand, but a powerful tool in the hands of an oncologist. They not only help to clarify the diagnosis, but also form the basis for individualized treatment. In combination with imaging and morphology, tumor markers open up a new level of accuracy and predictability in the diagnosis of kidney cancer. If you or your doctor suspects kidney pathology, do not delay the examination. Tumor markers can provide an important clue even before the disease declares itself in full voice.

Author: Ulyana Anatolyivna Dzyuba

Director of Medi Lab Plus LLC, a doctor of the highest category. Has over 45 years of practical experience in medicine and laboratory diagnostics. Founder and head of the laboratory since 2007. More details…