Introduction
Chemotherapy for colorectal cancer represents the third important pillar in the treatment of cancer besides surgical removal and radiation. Chemotherapy is a mixture of different drugs, so-called cytostatics, which are administered to the patient in several stages over a longer period of time. They are designed to specifically identify and kill malignant cells on the basis of certain cell characteristics.
When does one need chemotherapy?
The fields of application of chemotherapy are manifold. In cancer of the colon it is mainly used in advanced stages after surgery as so-called “adjuvant chemotherapy”. From stage 2 of the disease on, this chemotherapy may become necessary if the operation cannot guarantee the complete removal of the cancer or if the cancer has already infiltrated too many wall layers and lymph channels of the intestine.
The benefit of chemotherapy is to kill undetected cancer cells in the body, so that recurrences in the intestine or other organs are less frequent. Chemotherapy can also be used to alleviate symptoms in so-called palliative therapy, where a cure cannot be assumed. In the case of rectal cancer, a cancer of the rectum, chemotherapy together with radiotherapy can also be carried out before the operation. The aim is to shrink the tumour, make the operation easier and reduce the recurrence of new tumours in the intestine.
Which chemotherapy is used?
The choice of the exact chemotherapeutic agent therefore depends on factors such as the tumor stage, the aggressiveness and nature of the tumor, the patient’s age and condition, as well as individual tumor-specific molecules, which may vary among patients. As with radiation therapy, the goals of chemotherapy can also vary. In a treatment with curative intent, chemotherapy can take on different tasks before and after surgery.
Palliative chemotherapy, whose aim is not to cure, can also alleviate symptoms and, if necessary, prolong survival. The chemotherapeutic agents are also known as cytostatic drugs. The name includes their property that they stop the growth of cancer cells and kill them.
The best known cytostatic drugs used in the treatment of colon cancer are The combination of these drugs represents the most common treatment regimen of so-called adjuvant chemotherapy. This is carried out after an operation with the aim of killing undetected cancer cells in the body and making a recurrence of the cancer less likely. Furthermore, antibodies are increasingly used in the treatment of colorectal cancer, which are supposed to enable a more targeted attack on the cancer cells. Their most well-known representatives are:
- 5-fluorouracil
- Oxaliplatin
- Folinic acid. – Bevacizumab
- Cetuximab
How long does chemotherapy take?
The chemotherapy is carried out within several cycles. Between the individual cycles there are recovery phases to give the body, which is also under attack by chemotherapy, opportunities to regenerate. The exact intervals depend on the individual therapy planning and the chemotherapeutic agents used.
In many cases, chemotherapy is administered over 1-2 days, followed by about 2 weeks of regeneration. Each individual dose is administered intravenously and may take several hours. In total, chemotherapy can last about 4-6 months.
