Chemotherapy: A Guide to Understanding Cancer Treatment
When combined with surgery, radiation or immunotherapy, chemotherapy plays an important role in cancer management.
What is Chemotherapy?
Chemotherapy refers to cancer treatment that uses one or more anti-cancer (chemotherapeutic) drugs. It works by slowing or stopping the growth of cancer cells, which grow and divide quickly. However, it also affects slowly dividing normal cells, resulting in potential side effects.
How Does Chemotherapy Work?
Chemotherapy works by interfering with the cell division and growth of rapidly dividing cancer cells in the body. The goal of chemotherapy is to damage cancer cells or kill them. Most types of chemotherapy work by interfering with the cancer cell's ability to undergo mitosis or cell division. Mitosis is the process through which a cell duplicates its DNA and divides it equally between two daughter cells during cell division. Chemotherapeutic drugs work in different ways to arrest mitosis:
- Alkylating agents cause damage to DNA by adding chemical groups to it. This prevents DNA from unwinding and duplicating during mitosis.
- Antimetabolites block the action of enzymes and proteins that are crucial for DNA production and cell division. They deprive cancer cells of important building blocks needed for DNA and RNA synthesis.
- Anti-tumor antibiotics prevent the action of topoisomerase enzymes. Topoisomerase enzymes are required to relax supercoiled DNA so it can be replicated. Their inhibition results in single and double-strand DNA breaks causing cell death.
- Mitotic inhibitors interfere with the formation of microtubules during mitosis. They prevent the formation of the mitotic spindle, a cellular structure needed to distribute chromosomes to daughter cells. This leads to cancer cell apoptosis as their DNA cannot be properly segregated.
Types of Chemotherapy Drugs
Chemotherapy drugs are classified by the way they work or by their chemical structures. Some of the major categories and examples include:
- Alkylating agents: Cyclophosphamide, ifosfamide, melphalan
- Antimetabolites: Fluorouracil, capecitabine, gemcitabine, methotrexate
- Plant alkaloids: Vincristine, vinblastine, paclitaxel, docetaxel
- Topoisomerase inhibitors: Irinotecan, topotecan
- Others: Cisplatin, carboplatin, doxorubicin, epirubicin, 5-fluorouracil
How is Chemotherapy Administered?
Chemotherapy drugs are often given intravenously through an IV line or catheter. This allows the drugs to quickly enter the bloodstream and reach cancer cells throughout the body. Some chemo drugs may also be given orally in pill form.
The way chemotherapy is administered depends on many factors like:
- Type and stage of cancer
- Location of cancer
- Aggressiveness of cancer
- Patient's general health
- Treatment plan or protocol (neoadjuvant, adjuvant, palliative etc.)
Most protocols require multiple chemo cycles given at regular intervals. During each cycle, drugs are given one after the other on specific days in intervals to allow normal cells time to recover between doses.
Potential Side Effects of Chemotherapy
While chemotherapy can successfully treat cancer, it also has potential side effects due to its action on normal cells which divide rapidly:
- Nausea and vomiting
- Loss of appetite and weight loss
- Fatigue and weakness
- Increased risk of infection (due to low white blood cell count)
- Easy bleeding or bruising (due to low platelet count)
- Anemia (due to low red blood cell count)
- Hair loss
- Mouth sores
- Diarrhea
- Neuropathy (numbness in hands and feet)
- Secondary cancers (sometimes years later due to chemotherapy)
Most side effects are usually short-term and disappear once treatment is over. However, long-term side effects like neuropathy may persist. Preventive medications, supplements and lifestyle changes can reduce severity and risk of side effects. Aggressive supportive care is also important during and after chemotherapy.
Key Points about Chemotherapy
- It uses drugs to kill cancer cells or slow their growth and spread in the body.
- Drugs work by interfering with cell division/mitosis of fast-growing cancer cells.
- Common chemo classes are alkylating agents, antimetabolites, plant alkaloids and more.
- Routes are intravenous or oral depending on cancer type, stage and protocol.
- Multiple drug regimens and cycles given periodically allow time for recovery in between.
- Side effects occur due to action on normal cells but are often temporary with aggressive supportive care.
- When combined with surgery, radiation or immunotherapy, chemotherapy plays an important role in cancer management.
For Deeper Insights, Find the Report in the Language that You want:
About Author:
Ravina Pandya, Content Writer, has a strong foothold in the market research industry. She specializes in writing well-researched articles from different industries, including food and beverages, information and technology, healthcare, chemical and materials, etc. (https://www.linkedin.com/in/ravina-pandya-1a3984191)