Chemotherapy drugs are simply medicines used to treat cancer. They work through a variety of mechanisms. It kills the rapidly growing cancer cells in our body. During acting on cancer cells, it also kills normal cells. Sometimes chemotherapeutic drugs shrink the tumor to facilitate surgical removal. Some of the effects produced are undesirable. They are known as adverse effects or side effects. Nausea and vomiting are the most common adverse effects observed in almost all chemotherapy drugs. Children are more likely to develop severe adverse effects. As I work in a tertiary care institute, I have seen many children suffer due to these drugs. Prophylactic treatments are given to minimize the side effects. This will be a series of posts about chemotherapeutic drugs, their mechanism of action, side effects, preventive measures, etc. My sympathy to you and your family, if any of your acquaintances are suffering from cancer.
If your child is going to take chemotherapy or is already getting it, you may need to learn everything to help your child. Ask your doctor about the treatment protocol. Chemotherapy drugs are often costly. Plan a financial journey and talk with your doctors regarding financial management. Cancer treatment may require a long time based on the protocol. Initially an intensive phase that requires heavy burden and frequent visits to hospitals. There are many forms of chemotherapy drugs, like oral, IV, subcutaneous, etc. Chemotherapy treatments are given in a hospital or local clinic with supervision. Paediatric hematologists and oncologists provide treatment for cancer.
Since the introduction of chemotherapy for the treatment of childhood cancer, the prognosis has improved dramatically.
This striking improvement in survival is a direct result of the incorporation of anticancer drugs into treatment regimens that previously relied only on surgery or radiotherapy for the primary tumor. Conventional frontline treatment regimens for most childhood cancers include multiple cytotoxic anticancer drugs administered at their maximum tolerated dose (MTD) intensity—regimens that typically produce substantial toxicity.
Basic principles of cancer chemotherapy
It is based on the goal of curing patients by eradicating all cancer cells.
- The proliferation rate of cancer cells is different from normal cells. The cytotoxic drugs kill cancer cells by first-order kinetics. That is, a given dose of drug destroys a constant fraction or proportion of a cell population.
- This principle includes the use of multidrug combination regimens (i.e., combination chemotherapy)
- The administration of chemotherapy before the development of clinically evident metastatic disease (i.e., adjuvant chemotherapy)
- The administration of drugs at the maximally tolerated dose rate (i.e., dose intensity).
- Cytotoxic drugs are more effective against tumors that have a high growth fraction.
- Cytotoxic drugs are either cell cycle-specific (CCS) or cell cycle-nonspecific (CCNS)
As the function of chemotherapeutic agents is to arrest cell growth (cytostatic) or to kill rapidly dividing cells (cytotoxic), they are invariably associated with a range of toxic side effects due to a lack of selectivity for normal compared to cancer cells. These are especially prevalent in cells and tissues with a high turnover, including skin, the gastrointestinal tract, and bone marrow, and lead to some of the more common and severe adverse reactions. Hair loss, mucositis, diarrhoea, vomiting, and neutropenia leading to sepsis are all common side effects.
Context of Chemotherapy
- Curative chemotherapy – where the objective is to cure the patient of cancer. Examples where curative intent chemotherapy is given are lymphoma and testicular cancer.
- Palliative chemotherapy – where cure is not feasible but the goal is to improve symptoms, quality of life and prolong survival through tumour stabilisation or shrinkage. In this context, palliative does not mean treatment at the end of life or symptom control e.g., control of cancer related pain or nausea.
- Adjuvant chemotherapy – where the tumour has been removed by surgery and chemotherapy is given to treat micrometastasis disease and reduce the likelihood of recurrence.
Neo-adjuvant chemotherapy, which refers to the use of chemotherapy to reduce the size of the tumour prior to surgery or radiotherapy
No more today. Hope to see you again for the next part.
Resources:
