What are two causes of malignant tumors

Causes cancer / malignant tumor disease

The genetic changes (mutations), which represent the decisive step in tumor development, are triggered in some of the patients by external influences. A number of such influences and damaging mechanisms are known that increase the risk of certain tumor diseases. Important examples are

  • Smoke
  • certain viral infections
  • Exposure to certain chemicals (especially chemotherapy because of previous tumor diseases) or asbestos
  • Exposure to ionizing radiation (also after radiation therapy)
  • Drugs that suppress the immune system (because the immune system can still eliminate some tumors in the early stages)

In addition, there may be certain hereditary characteristics that carry a higher risk of developing certain tumor diseases. An important example is a mutation in the BRCA gene, which significantly increases the risk of developing breast cancer. In this case, the mutation in a BRCA gene disrupts mechanisms that can repair cancer-causing mutations in potential tumor cells.

Certain other diseases can also increase the risk of developing a tumor. Examples are cirrhosis of the liver (increased risk of liver cancer) or adenomas = benign tumors in the large intestine (preliminary stages with increased risk of colon cancer).

It is important that the determination that an individual patient has both a risk factor and a “matching” tumor does not secure this connection, but only indicates a probability for this connection. For example, although very rarely, lung cancer in a smoker can be caused by anything other than smoking.

Frequently, however, no “probable” causes for the development of the cancer can be named. Then the tumor disease has to be understood as fateful and coincidental. Questions like: “Why did this tumor develop in me?” Or “What have I done wrong in my life?” Are completely natural reactions. In most cases, however, these questions are irrelevant when planning the best treatment for a newly diagnosed tumor disease. This is often true even if a risk factor for the type of cancer is found. It is particularly important to look ahead and not backwards. However, the detection of certain genetic risk factors can influence the further prevention strategy and make examinations of family members recommended.