Searching for the causes of cancer

 In addition to investigating the causes, researchers are motivated by one thing above all else: the search for a cure.

Published on July 30, 2021

Over 19 million cases worldwide each year – and the number is rising. Some people are affected in old age, others in childhood. Whenever cancer strikes, it is a life-changing disease. Its exact origins have been the subject of research since the advent of modern medicine over 150 years ago. As well as investigating the causes, researchers are motivated by one thing above all else: the search for a cure.

There are numerous factors that influence when and whether a person will develop cancer over the course of their life. Scientists primarily focus on genetically harmful influences such as tobacco smoke or viruses that modify our cells – for example, by way of <a href="inflammatory processes">inflammatory processes</a>. [1] After all, we know from research by 19th century pathologist Rudolf Virchow that cancer cells don’t simply appear out of nowhere or enter the body via bacteria. Rather, cancer develops from previously healthy cells that become diseased and consequently mutate. [2] In addition to external influences, our inherited genetics also affect our predisposition to cancer. In other words, genetic material with an inherited defect can increase the likelihood of cancer but cannot pass the disease on directly.
Hepatitis B viruses, which are transmitted via bodily fluids, can lead to cirrhosis of the liver and hepatocellular cancer in the event of chronic inflammation. The virus is responsible for some 50 to 60 percent of cases of hepatocellular cancer worldwide.
Malignant tumors are particularly aggressive and threaten the lives of those they affect due to the explosive growth of cells, invasion of neighboring tissues, and formation of secondary growths known as metastases. Today, tumors are classified using a range of different techniques. With the help of <a href="https://www.siemens-healthineers.com/medical-imaging" target="_blank">medical imaging</a>, for example, experts can extract tissue and perform microscopic examinations to assess the degree to which healthy tissue differs from diseased tissue. Valuable insights are derived from the size and spread of the primary tumor, or the presence of distant metastases. The existence of a tumor can also be demonstrated with the help of laboratory diagnostic methods, such as the use of <a href="using prostate-specific antigen (PSA) as an example">tumor markers</a>.
The levels of certain substances in the blood provide information that can be used to detect cancer. For example, when the level of prostate-specific antigen (PSA) is unusually high, there is also a higher probability of prostate cancer.
Find out more
The ability of our cells to divide – a process known as mitosis – plays a fundamental role in our existence but is also a particularly treacherous characteristic when it comes to cancer. Theoretically, a single diseased cell that divides continually is enough to cause considerable harm. This is because healthy cells “know” – based on the information contained in their genetic material – which tasks they are supposed to perform and when it is time for them to die. That is not the case with malfunctioning cells, which not only change in terms of their appearance but also begin to divide in an uncontrolled manner. Once they become tumors, these cells even form their own blood vessels and invade surrounding tissues. This can have a variety of consequences depending on where in the body it takes place and what the underlying causes are.
There are now over 300 known types of cancer [3], each of which is different – and the course they take can also differ from one person to the next. The basis of all deliberations is therefore the provision of treatment that is tailored to the individual case and the individual patient. The scientific consensus on how to tackle cancer is centered around the removal of malignant tumors and stemming or halting the growth or spread of diseased cells. Some tumors can be removed surgically, whereas others are first reduced in size using drugs or <a href="Radiotherapy" data-ste-link-id="1685647230.on/cp-text-image-e7fe2680:3632417838.Radiotherapy:3468097550">radiotherapy </a>. These techniques are also used to destroy the last remnants of diseased cells following surgical intervention.

Also known as radiation therapy, radiotherapy involves the use of ionizing or particle radiation – generally high-energy X-rays – on a localized area in order to shrink or completely destroy tumors within the treatment field. 

<p>Some treatments are intended to stimulate the body’s own defense mechanisms in order to fight cancer cells, as is the case with immunotherapy. It is the cancer cells themselves, however, that are the target of the three main pillars of modern cancer therapy: surgical removal of the tumor, chemotherapy, and radiotherapy.</p> <p>Treating cancer using radiotherapy involves the use of ionizing or particle radiation to damage the genetic material of cells in order to prevent them from dividing further. This has proven to be one of the most effective methods for shrinking or eliminating tumors since the start of the 20th century. Although the radiation also damages healthy cells, these cells are unlike their diseased counterparts in that they are better able to repair themselves – depending on the severity of the damage. Whereas the cancer cells die off, the plan is for the healthy tissue to regenerate. For this reason, historically, radiation dose has been administered over several sessions, known as fractions—to give the healthy tissues time to repair themselves between treatment sessions. However, recent advances in precision that enable very targeted treatments that do a better job of protecting the surrounding healthy tissues have enabled more precise radiotherapy treatments, such as intensity-modulated radiation therapy and image-guided radiation therapy. </p>
<p>Single, very high dose of radiation is all that is used in a special form of precision radiotherapy known as radiosurgery, which seeks to kill as many tumor cells as possible in one go.</p><p>Despite the regenerative capacity of healthy cells, one of the key aims in modern research is to use imaging techniques to more accurately delineate the radiation of the diseased region from the surrounding tissue and thereby protect the undamaged tissue as much as possible – but the question is how.</p><p>One option is to use artificial intelligence (AI), which is capable of “excluding” certain movements of the body during imaging that could affect the quality of the results. This is particularly useful for movements that the patient simply cannot avoid making over a prolonged period of time, such as breathing.</p>
<p>For more information, please refer to the experiences of the University Medical Center Hamburg-Eppendorf (UKE)</p>
Precise radiotherapy planning with Directi4D from Siemens Healthineers
Or read the interview with Professor Jürgen Debus, Medical Director of the Department of Radiation Oncology and Radiotherapy at Heidelberg University Hospital in Germany.
In the Heidelberg University Hospital the SOMATOM Confidence RT Pro system as well as the syngo.via RT Imaging Suite is working perfectly in combination.
<p>In addition to the tried and tested technique of radiotherapy, other fledgling areas of research are providing new hope for those engaged in the battle against cancer. One of these areas encompasses particle therapy, whereby patients are irradiated with protons and heavy ions. The physical properties of these particles enable them to penetrate even deeper into tissue and to provide a very high level of precision during treatment. This also allows the delivery of a higher radiation dose, thereby improving the chances of curing the patient. The technique could also be of interest for slow-growing or poorly vascularized tumors, as well as for tumor types that are relatively unresponsive to conventional radiotherapy using photons.</p><p>The battle against cancer goes on, but the overall message is a positive one: Despite the growing number of new cases, the survival rate for many types of cancer has increased significantly over recent decades. [4]</p>
<p>Are you interested in the history of X-ray technology and the early days of cancer therapy? Then why not embark on a journey through history at the MedMuseum:</p><p><a href="https://www.medmuseum.siemens-healthineers.com/en/stories-from-the-museum/battle-against-cancer" target="_blank">The battle against cancer</a><br><br><a href="https://www.varian.com/" target="_blank">Get to know Varian</a><br></p>
History of X-ray technology and the early days of cancer therapy