Chemotherapy is the use of drugs to kill cancer (malignant) cells by targeting rapidly dividing cells. The drugs travel throughout the body, making chemotherapy a systemic treatment that can kill cancer cells anywhere in the body. Chemotherapy drugs are often used in combination, and may be used along with other treatments for lung cancer, such as surgery, radiation therapy, immunotherapy, or targeted therapy.
Chemotherapy drugs are also called anti-neoplastic drugs because they are used to help prevent the development, growth or spread of neoplasms (tumors).1-3
How is chemotherapy used?
Chemotherapy may be used:1
- Before surgery to reduce the size of a tumor to make it easier to remove
- After surgery to kill any remaining cancer cells in the body
- In combination with radiation therapy for lung cancers that cannot be removed with surgery
- As the main treatment for patients who have advanced cancer or who aren’t healthy enough for surgery
- In combination with immunotherapy for certain lung cancer patients
Chemotherapy drugs for lung cancer can be broken down into categories based on their action, including alkylating agents, antimetabolites, antimicrotubule agents, and topoisomerase inhibitors.
Alkylating agents treat cancer by interfering with cell metabolism and growth.2 Examples of alkylating agents used for lung cancer treatment include carboplatin (Paraplatin®), and cisplatin (Platinol®).
Antimetabolites are similar in structure to substances that are essential for growth and division of both normal and cancerous cells. These drugs are most effective in blocking growth and division of rapidly growing tumors.2 Examples of antimetabolites used for lung cancer treatment include pemetrexed (Alimta®), gemcitabine (Gemzar®), and very rarely, methotrexate (Otrexup®, Rasuvo®, or Trexall®).
Antimicrotubule agents are drugs that block cell growth by stopping mitosis (cell division).4 Examples of antimicrotubule agents used for lung cancer treatment include paclitaxel (Taxol®), vinorelbine (Navelbine®), docetaxel (Taxotere®), and vinblastine (Velban®).
Topoisomerase inhibitors block the enzymes that break and reconnect DNA strands (topoisomerases) that are needed for cell division and growth.4 Examples of topoisomerase inhibitors used for lung cancer treatment include irinotecan (Camptosar®) and etoposide (VePesid®, Toposar®).
Possible side effects of chemotherapy
Because chemotherapy drugs attack all cells that are dividing quickly, they affect cancer cells as well as normal cells that divide quickly, such as cells in the bone marrow, the lining of the mouth and intestines, and hair follicles. While the side effects of chemotherapy are dependent on the type and dosage of drugs given, some common side effects include:1
- Hair loss
- Mouth sores
- Diarrhea or constipation
- Decreased white blood cells, which increases the risk of infections
- Decreased blood platelets, which can cause easy bruising or bleeding
- Decreased red blood cells, which can cause fatigue
- Memory changes
- Changes in sexual desire
Generally, these side effects stop after treatment is completed. However, some side effects may develop later on such as other types of cancer, infertility, or thyroid problems. In addition, there are drugs that can be given along with chemotherapy to reduce some of the side effects, such as drugs to prevent nausea and vomiting or drugs to boost the white blood cells. Patients should report all side effects to their doctor or nurse, who can suggest ways to alleviate and reduce the occurrence of side effects.1,3