TYPES OF CHEMOTHERAPY

Introduction

Chemotherapy is a type of treatment recommended for patients with cancer. Chemotherapy involves delivering certain drugs that kill the rapidly growing cells of the body, including tumor cells. Several types of chemotherapy treatments are available based on the type and stage of cancer. Patients with an early diagnosis of cancer have a more favorable prognosis with chemotherapy. Most patients receive more than one chemotherapy drug to enhance treatment efficacy. Very few cancer hospitals offer advanced chemotherapy treatment and appropriate care before and after chemotherapy.

Delivery of Chemotherapy Drugs

The oncologists at the HCG Cancer Hospital can deliver chemotherapy drugs through various routes, such as oral, intravenous, and intramuscular administration. The other routes of administration recommended at chemotherapy centers include intrathecal chemotherapy, intraperitoneal chemotherapy, and intraarterial chemotherapy. The intravenous delivery of the drugs can be through a port, needle, catheter, or pump. Patients generally require the delivery of the drugs through multiple sessions. In most cases, the administration of drugs occurs within a few minutes to a few hours at the chemotherapy care centers. However, some patients may require continuous drug infusions that may take a few days, depending on the chemotherapy treatment protocol for a particular cancer.

Mechanism of Chemotherapy

Several types of drugs are available for chemotherapy treatment. The choice of drugs depends on the type and stage of the disease. In addition, the response to previous treatment also affects the choice of further treatment. For instance, for patients not responsive to conventional chemotherapy, other options like targeted therapy or immunotherapy may be explored. There are several classes of drugs based on their mechanism of action. These include alkylating agents, anti-metabolites, plant alkaloids, and topoisomerase inhibitors. These drugs target the essential processes in cancer cells and prevent their growth and multiplication.

Use of Chemotherapy

There are various applications of chemotherapy in cancer management. These include:

• Curative therapy: Chemotherapy is the primary treatment for most types of cancer. It may completely cure the cancer with minimal chances of recurrence. For example, blood cancer, lymphomas, and cancer in children.
• Adjuvant therapy: In most stage II and III cancers, patients may undergo various types of cancer treatment, such as surgery, radiation therapy, and chemotherapy. Adjuvant chemotherapy involves administering chemotherapy drugs after surgery and/or radiation therapy to destroy the remaining cancer cells.
• Neoadjuvant therapy: Neoadjuvant chemotherapy involves delivering the drugs before surgery and/or radiation therapy. Neoadjuvant chemotherapy aims to reduce the size of the tumor through chemotherapy so that it can be easily removed by surgery or treated with minimal doses/sessions of radiation therapy. This approach is usually recommended for locally advanced cancers.
• Palliative chemotherapy: Chemotherapy is also an important component of the palliative care strategy for patients with advanced stages of cancer. Although chemotherapy drugs may not cure cancer in such patients, they can reduce the symptoms and improve the quality of life. Some patients may live for many months to years if they respond well to treatment.

Types of Drug Therapies

There are various types of drug therapies based on the types of drugs delivered. Consult with the best oncologist in Mumbai for appropriate chemotherapy treatment. Some of the types of chemotherapy include:

Chemotherapy

Conventional chemotherapy, an oncology treatment, is one of the most frequent treatment strategies for patients with cancer. However, these drugs kill or prevent the growth of all the rapidly dividing cells in the body, irrespective of whether they are cancerous or not. Thus, conventional chemotherapy drugs cannot differentiate between cancerous and non-cancerous cells and attack the same process in both types of cells. It may result in some side effects of these drugs.

Types of Chemotherapy

Types of chemotherapy can be divided based on the classes of drugs delivered and the routes of drug administration.

Based on the Classes of Drugs

The types of chemotherapy treatments may be classified based on their mechanisms of action. These include:

• Alkylating agents: These agents interfere with the process of cell division by damaging DNA. The cancers treated with alkylating agents include lymphoma, multiple myeloma, breast cancer, lung cancer, and ovarian cancer.
• Antimetabolites: These agents interfere with cell replication and proliferation by substituting RNA and DNA with amino acids. The cancers treated with antimetabolites include ovarian cancer, breast cancer, and leukemia.
• Topoisomerase inhibitors: Topoisomerase is an enzyme that untangles DNA. Replication of DNA can only take place after untangling. Topoisomerase inhibitors block the enzyme and prevent DNA replication.
• Plant alkaloids: These drugs are also known as mitotic inhibitors. They inhibit mitosis and prevent the cancer cells from dividing. Cancers treated with plant alkaloids include myeloma, lymphoma, leukemia, and breast cancer.
• Nitrosoureas: These drugs interfere with the process of repairing DNA. The function of these drugs is similar to that of alkylating agents.
• Anti-tumor antibiotics: These drugs are obtained from microorganisms. The mechanisms of these drugs include damage to DNA or preventing DNA synthesis.
• Anthracyclines: These drugs block the enzyme that plays a vital role in DNA replication. Anthracyclines inhibit the division of cancer cells.

Based on Route of Administration

The types of chemotherapy treatment may be divided based on routes of administration. These include:

• Intravenous administration: It is one of the most common routes for delivering chemotherapy. The route of administration is vein or blood vessel. It is usually given in drip form.
• Intramuscular administration: The route of administration of the drug involves muscle.
• Oral administration: Oral administration of these drugs may be in the form of tablets or capsules.
• Topical administration: This route is generally chosen for delivering drugs to patients with skin cancer. These formulations are available in the form of creams and gels.
• Intraperitoneal chemotherapy: This route of chemotherapy administration involves direct administration of the drugs in the abdominal cavity to treat cancers of the abdominal organs, particularly the peritoneum.
• Intravesical chemotherapy: Intravesical chemotherapy comprises the administration of chemotherapy drugs into the urinary bladder through cystoscopy. It is used for the treatment of bladder cancer.
• Intrapleural chemotherapy: Intrapleural chemotherapy involves the administration of anticancer drugs in the chest cavity/pleura to treat lung cancer.
• Intrathecal chemotherapy: Intrathecal chemotherapy drugs manage cancers of the brain and spinal cord. The drug is delivered into the intrathecal space.
• HIPEC: Hyperthermic intraperitoneal chemotherapy (HIPEC) is a specialized form of chemotherapy used to manage cancers that develop in the abdominal area. In the first stage, the surgical oncologist performs the surgery to remove the tumor as much as possible. Then heated chemotherapy drugs are delivered into the abdominal cavity through the catheters.

Targeted Therapy

There are certain proteins and enzymes specific to cancer cells that assist them in dividing, growing, and proliferating. Targeted therapy is a type of cancer treatment that targets these proteins and enzymes. As the therapy only targets specific targets on cancer cells, it spares healthy cells. The targeted therapy functions through protein alterations, preventing chemical signals that help cancer cells grow, triggering the immune system, and preventing the formation of new blood vessels that supply blood to the tumor.

Immunotherapy

It uses the patient’s immune system to fight against cancer cells. Generally, the immune system identifies and kills cancer cells. However, in certain cases, the cancer cells, through certain mechanisms, hide themselves from the immune system. These cells then grow, divide, and proliferate, resulting in a tumor. Immunotherapy functions through two mechanisms. First, it improves the overall efficacy of the immune system. Second, it interferes with the hiding mechanism in the cancer cells, making them vulnerable to the attack of the immune system.

Hormonal Therapy

Certain types of cancer are hormone-dependent. Hormone therapy may work by blocking the production of certain hormones responsible for cancer growth or interfering with the effects of certain hormones on cancer cells. Hormone therapy is generally used to manage prostate cancer, breast cancer, ovarian cancer, and uterine cancer, as these cancers are dependent on hormones.

Preparing for Chemotherapy Treatment

Some measures may help the patients effectively prepare for medical oncology treatment. These include:

• Selecting the best cancer treatment hospital to undergo chemotherapy and other cancer treatments
• Getting detailed information about chemotherapy from the oncologists related to the duration of treatment, number of sessions, side effects, and management of those side effects
• Take effective steps beforehand to reduce the chances of the occurrence of side effects.
• Modifying the schedule to adjust according to cancer hospital visits and treatment sessions

Care after Chemotherapy Treatment

Care after chemotherapy treatment is important. It helps the patient prepare for the next chemotherapy session and improves the quality of life. Some care tips during and after medical oncology treatment include:

• Avoid visiting places with increased risk of infection, e.g., closed AC halls with gatherings.
• Avoid interacting with people who have flu or other infections.
• Eat a healthy diet.
• Avoid eating food that is spoiled or undercooked; preferably, eat homemade, freshly cooked food.
• Drink safe drinking water.
• Take adequate rest and have good quality sleep.
• Do not skip the follow-up schedule.
• Immediately consult the doctor if there is any concern/unusual symptom.

Efficacy of Chemotherapy Treatment

Several factors affect the efficacy of chemotherapy treatment. These include types and stages of cancer, response to treatment, severity of side effects, age of the patient, and overall health/performance status. Cancer that is sensitive to chemotherapy drugs may go into remission. Further, oncologists at the cancer hospital critically monitor the effect of chemotherapy, and based on the evaluation, they may continue the treatment, add more drugs to the treatment regimen, or switch the patient to another treatment option. Patients are advised to visit the hospital for follow-up visits after equally important treatment completion.

Side Effects of Chemotherapy Treatment

Chemotherapy treatment may cause both short- and long-term side effects. Advanced cancer chemotherapy centers effectively manage treatment side effects. The short-term side effects include

• Fever
• Fatigue
• Loss of appetite
• Diarrhea
• Nausea
• Vomiting
• Constipation
• Pain
• Oral sores
• Change in taste
• Hair loss (sometimes)

The long-term side effects of medical oncology treatment include:

• Change in cardiac functioning/LVEF
• Lung problem
• Neurological problems like peripheral neuropathy
• Kidney problems
• Sometimes, infertility

Conclusion

Chemotherapy plays a vital role in the management of cancer. It targets and kills cancer cells. It improves the survival rate for several types of cancer, especially when cancer is diagnosed early. The factors affecting the choice of chemotherapy include the type and stage of cancer, treatment goals, and the patient’s overall health. There are several types of medical treatment. Conventional chemotherapy has some side effects compared to other treatment options, such as targeted therapy, immunotherapy, and hormone therapy. Patients should choose a center equipped with advanced cancer treatment services. Most patients receive chemotherapy at chemotherapy daycare centers. Consult with the best medical oncologist in Mumbai for improved treatment outcomes.