In this blog post, we will look at the nature of the disease of cancer, why we fear it, and the development of cancer treatment.
Cancer remains the number one cause of death. Many people have probably experienced someone close to them dying from cancer. What is cancer and why does it make us so afraid?
Humans break down cells that have served their purpose and divide new cells to maintain life. However, if a mutation occurs that causes cells to divide more than necessary, the resulting growth forms a convex shape like a lump, which is called a tumor. Among these tumors, malignant tumors that grow constantly and destroy surrounding normal cells are called cancer. Cancer is not just a tumor that grows, but has a complex effect on various systems in our body, posing a threat on a different level than other diseases. Cancer is particularly dangerous because it often does not show any symptoms at first, but then suddenly worsens and leads to fatal consequences. This characteristic makes cancer a more frightening and uncertain disease, and it is easy to miss the timing of treatment.
The incidence of cancer is increasing every year due to modern lifestyles, environmental pollution, and changes in eating habits, but fortunately, the survival rate of cancer is also steadily increasing. This is due to the rapid development of diagnostic technology and treatment methods, and the widespread recognition of the importance of cancer prevention and early diagnosis. Among them, radiation therapy and chemotherapy using anticancer drugs are making a great contribution to improving survival rates. So what is the principle of these treatments and how are they evolving?
Radiation therapy is an anticancer treatment that began to be widely used after German physicist Wilhelm Conrad Röntgen discovered X-rays in 1895 and high-energy radiation therapy machines were invented in the 1950s. Radiation therapy is a treatment that directly removes cancer cells using high-energy radiation. Radiation refers to the flow of particles moving at high speed and electromagnetic waves with short wavelengths, which penetrate our bodies and cause ionization. Radiotherapy is a treatment that uses the principle of killing cancer cells by causing chemical denaturation of DNA and cell membranes, which are essential for life activities, that occur at this time.
Radiation therapy has the advantage of being able to painlessly eliminate cancer cells, but it has the side effect of damaging normal cells in addition to cancer cells. To solve this problem, special radiation therapy has recently been conducted using CT and MRI to reconstruct the location, size, and shape of tumor cells in 3D, and to focus radiation on cancer cells only. In addition to curative radiation therapy aimed at complete recovery, palliative radiation therapy is also used to alleviate the symptoms of cancer patients, thereby minimizing side effects. Thanks to these technological advancements, the effectiveness of radiation therapy is improving, and in particular, the technology that focuses radiation on specific areas only and minimizes damage to surrounding tissues is becoming the core of cancer treatment.
At the end of the 19th century, the establishment of cell theory led to rapid development in the life sciences, and scientists began to accelerate the development of anticancer drugs. The development of anticancer drugs began with the use of “sulfur mustard,” a toxic gas used by the German army during World War I. After various studies and experiments, several types of anticancer drugs were developed that target cancer cells. Anticancer drugs are classified in various ways based on the principle of preventing the growth, division, and differentiation of cancer cells. For example, alkylating agents that directly bind to DNA and cause damage, or antimetabolites that competitively act with normal metabolic substances during the DNA replication process to inhibit the proliferation of cancer cells.
However, anticancer drugs can affect not only cancer cells but also normal cells. In particular, anticancer drugs are made by taking advantage of the characteristics of cancer cells that divide rapidly, so there is a high possibility that rapidly dividing tissues, such as hair follicle cells or mucosal cells in the digestive system, will also be damaged. For this reason, patients undergoing anticancer therapy may experience side effects such as hair loss, mouth sores, and organ function damage. However, new treatments to reduce these side effects are being continuously researched, and efforts to minimize the side effects of cancer treatment are ongoing.
Targeted therapies that selectively attack only cancer cells are being developed to address these issues. Targeted therapies are anticancer drugs that target molecular structures or cell signaling pathways that are unique to specific cancer cells and are designed to protect normal cells as much as possible. These block the survival of cancer cells in various ways, including by inhibiting signaling pathways and angiogenesis. Examples include Avastin, which inhibits the growth of cancer cells by inhibiting new blood vessels, and Glivec, which is known as a treatment for chronic myeloid leukemia.
However, targeted therapies are not effective for all types of cancer, and because they only respond to specific targets, they may have limited effects depending on the type of cancer and the patient’s condition. In addition, targeted therapies are difficult to develop and are expensive, so the economic burden is also high. In particular, long-term medication can cause drug resistance, which can lead to a gradual decrease in treatment effectiveness. To solve this problem, researchers are using biological indicators to study personalized treatments optimized for each patient, and it is expected that such personalized treatments will become a new direction for cancer treatment in the future.
Cancer is a disease with a long history, as it was found in the prostate of a mummy 2,200 years ago. However, with the development of modern science and technology, cancer treatment has made rapid progress in just a few decades. Scientists will continue to conduct research to conquer cancer, and cancer will no longer be a source of fear but will be transformed into a disease that can be managed and treated on a daily basis.
