Most common types of cancer

Cancer does not have a unified clinical picture. But all forms of cancer involve the mutation of the genetic material in the affected cells. The location of the cancer cells within the body will influence the type of symptoms that occur. For instance, the warning signs of breast cancer and leukaemia (blood cancer) differ greatly in accordance with the functions performed by the affected organs.


Defining cancer is a difficult task, even for cancer researchers. It is much easier to explain the term in relation to its causes.

Today, we know that the cells of a tumour derive from an original cell which at some point in time – deviated from the normal, controlled division process – generally decades before a lump becomes physically or visibly noticeable. Every life begins as a single cell. This cell divides and multiplies itself to create new specialised cells. Normal, specialised cells are compatible with each other and function harmoniously together. They group together to create tissues which form the various organs.

Cancer develops when normal cells change – often during various intermediate steps – into malignant cells that start to divide uncontrollably. When the body’s defence mechanism is not able to destroy them, more and more diseased cells are created to form a localised growth (tumour). The surrounding tissue is subsequently also affected (infiltration). Cancer cells can travel via the lymphatic and circulatory systems to reach other parts of the body, where they then create new cancer growths (metastases). In the case of leukaemia and certain lymphatic cancers, the cancer cells distribute themselves rapidly throughout the entire body.

Cancer is the collective term for around 150 different types of malignant organ tumours and diseases of the hematopoietic and lymphatic systems.

After cardiovascular and circulatory disorders, cancer the second most common cause of death in Switzerland. A cancer diagnosis, however, is not a death sentence. Over 30,000 people are diagnosed with cancer each year and around half of them are able to be cured. The chances of recovery are much better if the cancer remains localised, compared to when metastases have already formed. That’s why early detection and timely treatment are of the utmost importance.

Benign tumour

Cancer, in other words the unrestricted growth of malignant tumours, is the result of mutations in the genetic material inside cells. These mutations can be caused by a variety of different factors, including genetically inherited risk factors, the natural ageing process, as well as external influences like lifestyle, harmful substances or infections. Some of these risk factors can be avoided – others can’t. Around a third of all cancers are caused by preventable causes such a smoking, alcohol consumption or an unbalanced diet.

Malignant tumour

Malignant tumours are cell growths with altered genetic material. These cells are no longer controlled by the body, so they are characterised by unrestricted growth. As they grow, they infiltrate healthy tissue and destroy it. The cells of a malignant tumour can travel through the bloodstream to reach other parts of the body. There they can form metastases, which can destroy the surrounding tissue.