Cancer immunotherapy - an overview

InfektionskrankheitenEach year 14.1 million people get the diagnosis of cancer. During a lifetime nearly every second man and every third women are cancer patients. The classical ways of cancer treatment are the resection of the tumor itself, as well as chemotherapy and radiation therapy. Often patients are treated by a combination of this aggressive procedures. 

A first step in understanding the development of cancer in patients organs is to unmask the identity of the tumor by deciphering the tumor genome and by examining where the tumor has its origin, e.g. if it is caused by a viral infection like liver cancer fostered by hepatitis B virus. 

In healthy people the immune system recognizes the difference between physiological body cells and cells not belonging to the body like pathogens (bacteria, viruses, ...). If the actions of the immune system are too weak, people suffer from permanent infections. If the immune system reacts to excessive, the body begins to fight against its own cells and autoimmune disorders occur. Right in the middle of this balanced reactions of the immune system tumors are able to escape from the immune reaction. Tumor cells show no signs of cells not belonging to the body and will therefore not be recognized by the immune system as cells which has to be eliminated; a tumor begins to grow and in the worst case to metastasise. Scientists think that many cells carrying tumor-triggering-mutations are eliminated by reactions of the immune system.

Within the last century a correlation between cancer and the immune system has been described. The growing field of cancer immunotherapy was initiated by the work of the pioneer William Coley (1862-1936, USA). Immunotherapeutic treatment of cancer has strong advantages: it provides a systemic approach against cancer cells spread over the whole body and it allows to treat all types of cancer (e.g. leukemia, lung cancer, melanoma, ...). By affecting tumors via the specifity, memory capacity and central & universal role of the immune system the immunotherapeutic treatment allows a treatment with fewer to non side effects and simultaneous long term protection. By either an unspecific stimulation of the immune system to booster a cytotoxic attack against tumor cells or a specific immune stimulation against cancer specific or tumor-associated antigens the patients immune system get mobilized to overcome cancer. 

As good as it seems, there is a lot work to be done to better understand the molecular background of cancer and to develop new immunotherapeutic medications. Currently there are a few medications approved and the effectiveness of several substances are tested within ongoing clinical trials - to cure cancer patients in the near future.

Author: Dr. Michaela Stolz