Chemotherapy is one of the most widely used and effective cancer treatments. It kills rapidly developing cells, such as cancer cells, and prevents them from proliferating.
Chemotherapy medications may be administered differently depending on the type of cancer and the type of treatment utilized. They can be given orally (oral chemotherapy), through the muscle (intramuscular injection), via the skin (subcutaneous injection), or into a vein(intravenous chemotherapy). Chemotherapy medications may be administered into the fluid around the spine in some situations (i.e., intrathecal chemotherapy). Under some conditions, two or more ways of administration may be employed concurrently. Chemotherapy chemicals enter the bloodstream and are distributed throughout the body regardless of the delivery technique.
The most popular method is intravenous injection. It is the most effective method for delivering the medicine into the bloodstream. Oral chemotherapy is more convenient and does not necessitate the use of specialized equipment.
It is frequently used in conjunction with other treatments such as surgery, radiation therapy, or hormone therapy. The use of combination therapy is determined by cancer stage and type, overall health before cancer therapies, the location of the cancer cells, and individual treatment preferences.
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Chemotherapy for non-cancer diseases
Some chemotherapeutic medications are effective in the treatment of various illnesses, such as:
Diseases of the bone marrow: A bone marrow transplant, also known as a stem cell transplant, can be used to treat diseases that affect the bone marrow and blood cells. Chemotherapy is frequently used in the preparation of a bone marrow transplant.
Immune system dysfunction: In certain conditions, such as lupus and rheumatoid arthritis, lower doses of chemotherapeutic medications can help manage an overactive immune system.
How does chemotherapy work?
Chemotherapy medications come in a variety of forms that each operate differently to kill cancer cells. Some may obstruct the growth and division of these cells. Others can aid in the self-destruction of cancer cells. Chemotherapy can also block critical blood and nutrients from reaching the tumor. For this treatment to be most effective, a specific type of cancer will be selected for treatment.
It can be used to:
1. cure cancer, depending on the type and stage of the cancer.
2. inhibit cancer cell development
3. prevent cancer cells from spreading to other regions of the body
4. kill cancer cells that may have moved from the primary tumor to other sections of the body
5. alleviate cancer-related symptoms
Chemotherapeutic agents
Chemotherapeutic medicines are classified according to their chemical structures and how they operate on cancer cells:
Alkylating agents
Alkylating compounds were among the first anti-cancer medications and are still among the most regularly used chemotherapeutic agents today. Alkylating chemicals cause cross-linking of DNA strands, unusual base pairing, or DNA strand breakage, stopping the cell from reproducing. Alkylating drugs are typically thought to be cell cycle phase nonspecific, which means they kill cells at several stages of the cell cycle. When a cancer cell is in its resting phase and not actively dividing, alkylating drugs are most effective. E.g., Busulfan (Myleran), Cyclophosphamide
Antimetabolites
Antimetabolites imitate cancer cell components and function at key stages of a cancer cell’s life cycle to impair its capacity to divide. They disrupt the RNA and DNA of cells. Anti-metabolites are active when cells divide. Fluorauracil, methotrexate, and fludarabine are a few examples.
Antimetabolites are only active during the cell cycle. Antimetabolites are most effective during the S phase of cell division because they primarily act on cells that are conducting DNA synthesis in order to produce new cells.
Plant alkaloids
Medicines are manufactured from natural ingredients. This class of medicines can inhibit a cell’s capacity to divide and become two cells, and it can also repair cell damage. Vincristine, Paclitaxel, and Topotecan are a few examples.
Hormonal agent
Corticosteroid hormones and sex hormones are the two categories of hormonal medicines used in cancer treatment. Some cancers (leukemia, multiple myeloma, and lymphoma) are treated with corticosteroids. Steroids are also used to minimize edoema around brain and spinal cord tumors. In combination with chemotherapy, steroids are used with other chemotherapy medicines. Corticosteroids include Prednisone and Dexamethasone. Tamoxifen and Leuprolide are two examples of sex hormones.
Topoisomerase inhibitors
Topoisomerase inhibitors work by weakening the structure of cancer cells, which is required for them to divide. E.g., Etoposide, Irinotecan
Antitumor antibiotics
Antitumor drugs are nonspecific for the cell cycle. They work by attaching to DNA and inhibiting RNA (ribonucleic acid) synthesis, an essential step in the production of proteins that are required for cell survival. For example, Cosmegen Dactinomycin Daunorubicin, Bleomycin.
Side effects occur during chemotherapy
- feeling and being sick
- hair loss
- a sore mouth
- dry, sore, or itchy skin
- neuropathy
- lymphedema
- memory problems
- concentration problems
- diarrhea or constipation
- Damage to lung tissue
- Heart problems
- Infertility
- Kidney problems
- Nerve damage
References
- https://www.tandfonline.com/doi/pdf/10.1080/02841860151116204
- https://www.ncis.com.sg/Cancer-Information/Documents/Pages/Patient-Education-Brochures/Chemotherapy%20Guide%20%28English%29%203.pdf
- https://www.healthline.com/health/chemotherapy#side-effects
- https://www.healthline.com/health/chemotherapy
