Cookie Settings

We use cookies to optimize our website. These include cookies that are necessary for the operation of the site, as well as those that are only used for anonymous statistic. You can decide for yourself which categories you want to allow. Further information can be found in our data privacy protection .


These cookies are necessary to run the core functionalities of this website and cannot be disabled.

Name Webedition CMS
Purpose This cookie is required by the CMS (Content Management System) Webedition for the system to function correctly. Typically, this cookie is deleted when the browser is closed.
Name econda
Purpose Session cookie emos_jcsid for the web analysis software econda. This runs in the “anonymized measurement” mode. There is no personal reference. As soon as the user leaves the site, tracking is ended and all data in the browser are automatically deleted.

These cookies help us understand how visitors interact with our website by collecting and analyzing information anonymously. Depending on the tool, one or more cookies are set by the provider.

Name econda
Purpose Statistics
External media

Content from external media platforms is blocked by default. If cookies from external media are accepted, access to this content no longer requires manual consent.

Name YouTube
Purpose Show YouTube content
Name Twitter
Purpose activate Twitter Feeds

Tolerant immune system increases cancer risk

No. 45 | 05/10/2015 | by Koh

Immune tolerance occurs when regulatory T cells suppress the activity of tumor-fighting immune cells. If this immune tolerance is very distinct, the risk for lung cancer increases by 100 percent and the risk for colon cancer by 60 percent, report scientists from the German Cancer Research Center (DKFZ) collaborating with colleagues from Berlin-based Epiontis GmbH. The researchers thus show for the first time that individual variations in immune tolerance have an impact on the development of specific types of cancer – long before the actual onset of the disease.

Picture: Wikimedia Commons

For a malignant tumor to form, cancer cells must evade an attack by the immune system. Numerous studies have shown that cancer spreads particularly aggressively if there is an unfavorable balance between suppressing and active immune cells in the tumor microenvironment. “But we didn’t know whether this is a consequence of an aggressive tumor or rather its cause,” says Rudolf Kaaks, epidemiologist at the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ).

Kaaks and his co-workers had a unique opportunity to pursue this question: The DKFZ in Heidelberg is a study center of the EPIC study, a project devoted to investigating the links between diet and cancer in almost half a million people throughout Europe. In initial EPIC examinations carried out from 1996 to 1998, blood samples were taken from all study participants and subsequently frozen. From the 25,000 participants in Heidelberg, the researchers now selected the blood samples from about 1,000 individuals who had developed cancer in the course of the observation period (including lung cancer, colon cancer, breast cancer, and prostate cancer). A group of 800 participants who were not affected by a malignancy was used as a control.

Sebastian Dietmar Barth and his colleagues from Kaak’s department counted suppressive regulatory T cells in the blood samples and determined the ratio of these cells to the total number of T cells, which also comprise the tumor-fighting cells. This ratio is called “immunoCRIT”. As a rule, the higher the immunoCRIT value, the more the immune system is being suppressed.

When comparing EPIC participants with extremely high or extremely low immunoCRIT values, the researchers found that with a strong increase, the risk of lung cancer rises by 100 percent, and the risk of colon cancer by approximately 60 percent. Women with very high immunoCRIT values experience an astounding three-fold increase in their risk of developing estrogen-receptor negative breast cancer*. Here, however, the researchers think that number of cases examined might be too low to make a definite statement. In cases of prostate cancer and estrogen-receptor positive breast cancer, the DKFZ epidemiologists found no links between immunoCRIT and cancer risk.

When tumor-fighting T cells are kept in check by regulatory T cells, which have an inhibitory function, scientists speak of “peripheral immune tolerance.” “With this study, we have demonstrated for the first time that the unfavorable ratio of immune cells already prevails long before the onset of the disease,” Kaaks says. “Hence it is more likely to be the cause than the result of cancer.”

The DKFZ researchers conducted this study in collaboration with Epiontis, a Berlin-based company that specializes in the epigenetic tests that were used to determine the ratio of the various T cell populations.

The scientists do not yet know why immune tolerance has an effect on the risks of developing certain types of cancer. A possible explanation may found in the results of prior research: tumors of the lung and bowel tend to be colonized by particularly high quantities of immune cells. The Heidelberg epidemiologists now plan to extend their investigation to other types of tumors.

* Breast cancer whose cells exhibit no receptor proteins for the female sex hormone estrogen.

Sebastian Dietmar Barth, Janika Josephine Schulze, Tilman Kuhn, Eva Raschke, Anika Husing, Theron Johnson, Rudolf Kaaks, Sven Olek: Treg-Mediated Immune Tolerance and the Risk of Solid Cancers: Findings From EPIC-Heidelberg
JNCI J Natl Cancer Inst.2015, DOI: 10.1093/jnci/djv224

With more than 3,000 employees, the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ) is Germany’s largest biomedical research institute. DKFZ scientists identify cancer risk factors, investigate how cancer progresses and develop new cancer prevention strategies. They are also developing new methods to diagnose tumors more precisely and treat cancer patients more successfully. The DKFZ's Cancer Information Service (KID) provides patients, interested citizens and experts with individual answers to questions relating to cancer.

To transfer promising approaches from cancer research to the clinic and thus improve the prognosis of cancer patients, the DKFZ cooperates with excellent research institutions and university hospitals throughout Germany:

  • National Center for Tumor Diseases (NCT, 6 sites)
  • German Cancer Consortium (DKTK, 8 sites)
  • Hopp Children's Cancer Center (KiTZ) Heidelberg
  • Helmholtz Institute for Translational Oncology (HI-TRON Mainz) - A Helmholtz Institute of the DKFZ
  • DKFZ-Hector Cancer Institute at the University Medical Center Mannheim
  • National Cancer Prevention Center (jointly with German Cancer Aid)
The DKFZ is 90 percent financed by the Federal Ministry of Education and Research and 10 percent by the state of Baden-Württemberg. The DKFZ is a member of the Helmholtz Association of German Research Centers.


Subscribe to our RSS-Feed.

to top
powered by webEdition CMS