CANCER TEST
TUMOR MUTATIONAL BURDEN
Tumor Mutational Burden
Information
Questions
Turn Around Time:
TMB – Tumor Mutational Burden: 2 weeks*
* If the sample needs to be enriched to ensure successful results, we will contact you
I Choose ΤΜΒ (Tumor Mutational Burden)
Tumor Mutational Burden (TMB) is the measurement of mutations carried by tumor cancer cells and is a modern predictive biomarker that your clinician (Oncologist) will evaluate in order to choose immunotherapy over other treatment options.
Human cells, including cancer cells, carry a large portion of their protein content on their surface. These proteins (neoantigens) are regularly inspected by immune system cells and can be recognized by T-lymphocytes, inducing an anti-tumor response. However, some cancers manage to “protect” themselves, preventing their detection by immune system cells.
Tumor cells that have a high TMB mean they have more neoantigens and a corresponding increase in cancer-fighting T-lymphocytes in their microenvironment and at the periphery. The higher the TMB of the cancer, the more likely it is that the immune system will recognize the cancer as “foreign” and attack it.
In conclusion, cancer that carries a high mutational load has a strong indication for immunotherapy (Checkpoint Inhibitors) which can lead to drastic improvement, eliminating the cancer’s ability to “evade” the cells of the immune system.
Tumor Mutational Burden (TMB) is a biomarker that measures the number of somatic mutations in cancer. In other words, it refers to the number of somatic mutations that exist per megabase (mut/MB). With this measurement, the cancer is classified as
- Cancer with low mutant load
- Cancer with medium mutant load
- Cancer with high mutant load
Long-term studies suggest that treatment decisions should take the TMB into consideration in order to maximize the effectiveness of treatment in each patient.
High-quality determination of TMB is the basis for therapeutic decisions regarding the choice of immunotherapy (Checkpoint Inhibitors) and should be considered as part of the diagnostic routine in the treatment of various tumors.
The clinical significance of this indicator is due to the fact that if it shows that the cancer carries a high number of mutations, this means that there is a higher number of abnormal proteins in the cancer, with the result that the cancer becomes more easily “perceived as foreign” tissue by the body’s defenses and more easily distinguishable from healthy tissue.
Tumor cells that have a high TMB mean they have more neoantigens and a corresponding increase in cancer-fighting T-lymphocytes in their microenvironment and at the periphery. The higher the TMB of the cancer, the more likely it is that the immune system will recognize the cancer as “foreign” and attack it.
In conclusion, cancer that carries a high mutational load has a strong indication for immunotherapy (Checkpoint Inhibitors) which can lead to drastic improvement, eliminating the cancer’s ability to “evade” the cells of the immune system.
At our vertically integrated Laboratory, we handle your sample in such a way as to minimize its unnecessary waste:
- The paraffin block is positioned once on the microtome to obtain tissue sections by experienced histotechnologists.
- Tissue sections are sequentially acquired in such a way as to provide immunohistochemistry diagnosis if required.
- Ensure maintenance of tissue sections for further molecular testing.
- Pathologists perform microdissection, in order to ensure the highest possible amount of cancer cells, removing all other necrotic cells or normal tissue that could affect the validity of the results.
- Immediately, the molecular biologist treats the tissue in a completely controlled environment with next-generation sequencing (NGS).
Frequently Asked Questions (FAQ)
The clinical significance of this indicator is due to the fact that if it shows that the cancer carries a high number of mutations, this means that there is a higher number of abnormal proteins in the cancer, with the result that the cancer becomes more easily “perceived as foreign” tissue by the body’s defenses and more easily distinguishable from healthy tissue.
Cancer that carries a high mutational load carries a serious indication for immunotherapy (Checkpoint Inhibitors) which can lead to drastic improvement, eliminating the cancer’s ability to “evade” the cells of the immune system.
The tests are performed on the surgical specimen (paraffin cubes) or the biopsy material (paraffin cube) from which your histological examination was performed or on the aspiration material (FNAB, EBUS) from which your cytological examination was performed. In our fully integrated Laboratory, the pathologist selects the most appropriate & representative paraffin cube, ensuring that the most appropriate sample will be used for the tests. Qualitative and quantitative parameters are checked.
In case your sample is not already at Microdiagnostics archive, please contact us immediately so that we can arrange for its safe and rapid transport to our laboratory. You will also need to quickly and easily complete the Consent Form.
Most of the time, the sample material we are called upon to handle is small because it has resulted from a minimally invasive method (needle biopsy, fluid aspiration, paraffin block with minimal material).
In our laboratory, Pathologists check in a timely manner whether the material to be examined is sufficient. If so, then a management algorithm is followed, with the aim of achieving the performance of multiple tests on the material (Immunohistochemistry, real-time PCR, NGS) in order to fully check the molecular profile of your tumor (proteins, genes, histological Grading).
In this case, and once sample enrichment manipulations have been exhausted, we contact your clinician to discuss alternative approaches in order to obtain the desired information to select the optimal treatment for you. Some examples:
- Performing an alternative test (e.g. Immunohistochemistry instead of PCR, or choosing Next Generation Sequencing (NGS))
- Performing Immunohistochemistry instead of FISH (Fluorescent In Situ Hybridization) and tubulin
- Possible blood sampling instead of tissue testing (liquid biopsy)
- Possible option to take a new biopsy or puncture
Contact us at 2310 23 22 72 and we will immediately assist you in quickly transporting the sample to our laboratory.
By cash, bank card, bank deposit, or Online interbank deposit.
One of the primary concerns at Microdiagnostics is the protection of your personal data as well as the strict observance of the conditions for the protection of your genetic material and medical results.
In full compliance with the General Data Protection Regulation (GDPR), we ensure that any examination conducted is done with your knowledge and consent.