## Prevention is more effective than treatment

Thanks to modern medical research, it is possible to discover the causes of many types of cancer as well as suitable methods of treatment. However, the most important thing for a person's health is to prevent cancer, or at least detect it at the earliest possible stage. Detection at the earliest stage possible is associated with the best prognosis for treatment and survival. Prevention consists of a healthy lifestyle and special medical examinations. The importance of prevention can be illustrated by two examples. The first example is adenomatous polyposis - a rare autosomal dominant disease. It is caused by a mutation in the tumour suppressor gene APC, which normally serves to regulate the renewal of intestinal mucosal cells. However, in the mutated state, when a person reaches the age of 20, it causes excessive cell division and the formation of many small tumours in the intestine and rectum. These growths are called polyps and are benign in the early stages. However, there is a risk that some of them may become malignant over time. With this diagnosis, on average, malignant transformation occurs around the age of 42, with the development of colon cancer. If polyps are removed at a benign stage, there is a high probability that the disease will not develop. However, colon polyps may not only be this hereditary form, but also the accidental occurrence of a mutation at a later age.

An example of the importance of prevention is breast cancer, which is curable in 75-90% of cases if detected early before the lymph nodes are affected. Breast cancer is best diagnosed by mammography and the sensitivity of a mammogram is such that it can detect a tumour as small as 5 mm, about the size of a pea. At this stage, it is likely that the tumour has not yet metastasized. According to statistics, 8 in 10 women will develop breast cancer.

The occurrence of cancer is essentially a natural process due to a failure of the body's regulatory mechanisms. Some factors of the external environment may contribute to its occurrence or development. However, the main cause of this disease is genetic changes over which we have little control. We can reduce the risk of cancer to some extent by adopting a healthy lifestyle, but the most important thing is to pay attention to prevention and take preventive examinations at the doctor's office. These can help detect cancer at an early stage when it is still treatable. We are also helped by the tools of modern genetics and molecular biology - they enable us to find out what kind of tumour it is, to determine the target sites for the action of drugs, and thus to transform cancer from a fatal disease into a curable one.