What is chemotherapy and the role of Oncologist?

Understanding Chemotherapy

Chemotherapy remains one of the cornerstone treatments in the fight against cancer. While newer therapies like immunotherapy and targeted treatments have emerged, chemotherapy continues to play a crucial role in many cancer treatment plans. Chemotherapy, often shortened to "chemo," is a type of cancer treatment that uses drugs to destroy cancer cells. These powerful medications circulate throughout the body in the bloodstream, attacking rapidly dividing cells. While this approach effectively targets fast-growing cancer cells, it can also affect healthy cells that divide quickly, leading to various side effects. Cancer specialist in Patna plays an important role in Chemotherapy.

Types of Chemotherapy

Chemotherapy drugs can be categorized based on how they work, their chemical structure, and their relationship to other drugs. Here are some of the main types:

1. Alkylating Agents
   • How they work: These drugs damage the DNA of cancer cells, preventing them from reproducing.
   • Examples: Cyclophosphamide, Cisplatin, Carboplatin
   • Commonly used for: Various cancers, including leukemia, lymphoma, Hodgkin's disease, multiple myeloma, and sarcoma
2. Antimetabolites
   • How they work: These drugs interfere with DNA and RNA growth by substituting for the normal building blocks of RNA and DNA.
   • Examples: 5-fluorouracil (5-FU), 6-mercaptopurine (6-MP), Gemcitabine
   • Commonly used for Leukemia, cancers of the breast, ovary, and intestinal tract
3. Anti-tumor Antibiotics
   • How they work: These drugs interfere with enzymes involved in DNA replication, which prevents the cancer cells from multiplying.
   • Examples: Doxorubicin, Mitoxantrone, Bleomycin
   • Commonly used for a wide range of cancers
4. Topoisomerase Inhibitors
   • How they work: These drugs interfere with enzymes called topoisomerases, which help separate the strands of DNA for replication.
   • Examples: Irinotecan, Topotecan, Etoposide
   • Commonly used for Certain leukemias, lung, ovarian, gastrointestinal, and other cancers
5. Mitotic Inhibitors
   • How they work: These drugs stop cells from dividing by disrupting microtubules, which are structures vital for cell division.
   • Examples: Paclitaxel, Docetaxel, Vinblastine, Vincristine
   • Commonly used for Breast, lung, and other cancers
6. Corticosteroids
   • How they work: These drugs are often used in combination with other chemotherapy drugs to help prevent nausea and vomiting, reduce inflammation, or even kill cancer cells in certain types of cancer.
   • Examples: Prednisone, Dexamethasone
   • Commonly used for Lymphomas, leukaemias, and multiple myeloma

Administration Methods

Chemotherapy can be administered in several ways:

1. Intravenous (IV): The most common method, where drugs are injected directly into a vein.
2. Oral: Some chemo drugs can be taken by mouth as pills or liquids.
3. Intramuscular (IM): Injected into a muscle.
4. Subcutaneous: Injected under the skin.
5. Intrathecal: Injected into the fluid-filled space between the layers of tissue that cover the brain and spinal cord.
6. Topical: Applied to the skin as a cream.

The method of administration depends on the type of drug and the type of cancer being treated.

Side Effects of Chemotherapy

While chemotherapy is designed to kill cancer cells, it can also affect healthy cells in the body, particularly those that divide quickly. This is what leads to many of the side effects associated with chemotherapy. It's important to note that not everyone will experience all side effects, and the severity can vary greatly from person to person.

Common side effects include:

1. Fatigue: This is one of the most common side effects of chemotherapy. It can range from mild tiredness to extreme exhaustion.
2. Nausea and Vomiting: These symptoms can start within hours of treatment and last up to a few days. Anti-nausea medications are often prescribed to help manage this side effect.
3. Hair Loss: Many chemo drugs cause hair loss (alopecia) because they damage the hair follicles. This can affect hair all over the body, not just on the scalp.
4. Bone Marrow Suppression: Chemotherapy can affect the bone marrow's ability to produce new blood cells, leading to:
   • Low white blood cell counts (neutropenia), increase the risk of infections
   • Low red blood cell counts (anaemia), causing fatigue and shortness of breath
   • Low platelet counts (thrombocytopenia), which can lead to easy bruising and bleeding
5. Mouth and Throat Sores: Some chemotherapy drugs can damage the cells lining the mouth and throat, leading to painful sores.
6. Appetite Changes: Some people lose their appetite, while others may experience changes in taste that affect their desire to eat.
7. Diarrhea or Constipation: Different chemotherapy drugs can affect the digestive system in various ways.
8. Skin and Nail Changes: Some drugs can cause dry skin, itching, or increased sensitivity to sunlight. Nails may become dark, yellow, or brittle.
9. "Chemo Brain": Some people experience cognitive changes such as memory problems or difficulty concentrating.
10. Nerve Damage (Peripheral Neuropathy): Certain chemotherapy drugs can cause numbness, tingling, or pain in the hands and feet.
11. Fertility Issues: Some chemotherapy drugs can affect fertility in both men and women. This may be temporary or permanent.
12. Emotional Changes: Dealing with cancer and its treatment can lead to mood swings, anxiety, and depression.

Long-Term Side Effects

While many side effects of chemotherapy resolve after treatment ends, some can persist for months or years, and others may not appear until long after treatment has finished. These can include:

1. Heart Problems: Some chemotherapy drugs can increase the risk of heart problems.
2. Lung Issues: Certain drugs can cause lung damage.
3. Increased Risk of Other Cancers: Some types of chemotherapy can slightly increase the risk of developing other cancers later in life.
4. Cognitive Changes: "Chemo brain" can persist in some cases.
5. Permanent Nerve Damage: In some cases, peripheral neuropathy may not fully resolve.

Managing Side Effects

Oncologists and their teams work closely with patients to manage side effects. Strategies may include:

• Medications to combat nausea, boost blood cell production, or manage pain
• Dietary changes to help with digestive issues
• Exercise and rest to combat fatigue
• Proper oral hygiene to prevent mouth sores
• Cold caps to reduce hair loss
• Counselling or support groups for emotional support

Conclusion

Chemotherapy remains a powerful tool in the fight against cancer, but it's not without its challenges. Understanding the types of chemotherapy and their potential side effects can help patients and their loved ones prepare for treatment. It's crucial to maintain open communication with the healthcare team about any side effects experienced during treatment.