Chemotherapy

It is the name given to the treatment with drugs to kill tumor cells in the treatment of cancer.

How does chemotherapy work?

Cancer cells, by their nature, tend to grow and multiply rapidly. Chemotherapy, on the other hand, can stop or slow down this rapid growth and proliferation by reducing it. However, chemotherapy can also damage normal cells, leading to side effects such as hair loss and diarrhea.

For what purposes is chemotherapy used?

Chemotherapy can be used alone in treatment choices that vary according to many characteristics of cancer, or it is usually used in combination with surgical intervention, radiotherapy and other treatment methods.

The situations in which chemotherapy treatment can be used are listed below.

• To minimize the mass before the operation or radiotherapy (neoadjuvant)
• As a preservative (adjuvant) to kill cancerous cells that remain after treatment and cannot be detected by imaging methods)
• Palliative chemotherapy is applied in order to increase the quality of life and prolong life in species that recur or spread to different regions, that is, metastasize.

The doctor decides on the use of chemotherapy. While making the decision, many factors such as the type of cancer, chemotherapy history -if there is any-, and the presence of additional diseases should be considered.

How is chemotherapy applied?

Chemotherapy has many different applications. You can find the most common ones below.

Intravenous (IV)

It is a classic application method. Chemotherapy is given directly into the vein. For this procedure, veins on the forearm or the back of the hand are generally preferred.

Intra-arterial method is the application of the chemotherapy drug directly to the tumor through the artery feeding the cancerous cells. In normal chemotherapy, the given drug first goes to the heart and lungs, and then its density decreases and disperses throughout the body. In cancer that has spread to many organs, intravenous chemotherapy is preferred to distribute the drug throughout the body. However, in some cases, the tumor can be found in a single area or in other organs. In this case, chemotherapy is applied to the artery feeding the mass, and in this way, the drug is sent directly to the target tumor. With this method, more chemotherapy drugs are given to the target and the density is found in the tumor. As a result, side effects are expected to be less than chemotherapy that spreads throughout the body.

Intraperitoneal (IP)

Our organs located in the abdominal area are surrounded by a membrane called peritoneum. Some cancers tend to spread on the peritoneal membrane. For this reason, the method of administering drugs through the peritoneal membranes is used.

Oral (by mouth) in pill form

Oral chemotherapy drugs, which come in pill, capsule, or liquid forms, are taken by mouth. Many smart drugs are taken orally with this method.

Targeted smart drugs

These drugs have been developed as a result of recognizing the growth signal pathways in the cell at the molecular level and succeeding in inhibiting the signals that send warnings to these pathways inside and outside of the cell with some drugs. The most outstanding achievements in the use of targeted smart drugs have been demonstrated in the adenocarcinoma of the lung.

In the process of cancer formation, that is, in carcinogenesis, the reason for the signal transmission pathways that increase growth uncontrollably are the genetic mutations that occur. Recognition of these mutations is very illuminating about the characteristics of the treatment given to individuals, and it has also great importance in improving the results. At this point, as we learn about the molecular pathways and the mutations therein, the number of targeted drugs specially prepared for abnormal changes increases. The increase in the number of these drugs developed, on the other hand, allows individuals with metastatic disease to extend their lifespan and increase their quality of life. At this point, the limited life expectancy provided by chemotherapies in metastatic cancers is significantly prolonged in individuals who are eligible for targeted smart drug therapies.

As a result of analyzes and studies on the DNA of the tumor, changes seen in cancerous cells are revealed. Detection of mutations in individuals with cancerous cells is available in two different ways. Detection of these mutations is important in monitoring the suitability of targeted drugs. The first detection method is molecular tests applied to the tumor taken from the patient together with biopsy. The other method is liquid biopsies, which are now more useful and reliable. This means that tests are performed with a blood sample without the need to take a biopsy from the patient. As a result of the test, the presence of a mutation in the DNA of cancerous cells circulating in the blood is detected and the appropriate treatment is applied. Liquid biopsies generally prevent the recurrence of biopsies in individuals who have previously undergone biopsy but do not have sufficient tissue. Chemotherapy is the preferred method for individuals who are not suitable for targeted therapy as a result of the analyses.

Cancer disease does not only vary between species, but even in individuals with cancer, same type of cancers shows differences. Factors such as each individual’s response to treatment, resilience, general conditions, and presence of concomitant diseases have paved the way for the development of personalized treatments.

Chemotherapy drugs are cytotoxic which means cell-killing drugs. The goal of these drugs is to prevent cells from growing, developing and multiplying. The general feature of cancer cells is their rapid growth and proliferation. For this reason, chemotherapy drugs play an effective role in the treatment of this disease.