Chemotherapy treatment

Traditional or standard chemotherapy works by disrupting the cell cycle. Each time a new cell forms it goes through a series of phases in order to become mature.  Traditional chemotherapy drugs target the different phases of the cell cycle. By disrupting or stopping a particular phase, a cancerous cell can no longer mature and divide and ultimately dies.

Unfortunately, traditional chemotherapy cannot tell the difference between healthy and cancerous cells. Normal cells are also damaged during treatment, particularly those that turnover more rapidly. These include the hair, nails and white blood cells (neutrophils), which are responsible for warding off infections. This is why traditional chemotherapy is often associated with hair loss and the need to take care to practice extra hygiene. Most normal cells will, however, recover over time, and effective medications are available to help alleviate many of the expected side-effects from treatment.

Traditional chemotherapy drugs can be further classified depending on how they work, their chemical structure or their relationship to other drugs. Some common traditional chemotherapy drug classes include:

• Alkylating agents: Damage the DNA of the cell across all phases of the cell cycle to stop cells from reproducing. e.g. carboplatin, cisplatin, cyclophosphamide, dacarbazine, ifosfamide, oxaliplatin.
• Antimetabolites: Interfere with a cell’s DNA and RNA to stop cells from reproducing. e.g. 5-fluorouracil (5-FU), capecitabine, gemcitabine, methotrexate, premetrexed.
• Anthracyclines: Change the DNA inside the cancer cell which stops them from multiplying. e.g. doxorubicin, liposomal doxorubicin, epirubicin.
• Topoisomerase inhibitors: These drugs block the action of topoisomerases which are enzymes that control the changes in DNA structure.  By interfering with topoisomerases, the DNA is damaged and can’t repair which leads to cell death. e.g. irinotecan, topotecan, etoposide, mitoxantrone.
• Mitotic inhibitors: These compounds are derived from natural products, such as plants, and are also known as plant alkaloids. They work by stopping cell division through the disruption of microtubules which pull chromosomes apart when a cell divides. Mitotic inhibitors can be further classified as taxanes (e.g. cabazitaxel, docetaxel, nab-paclitaxel, paclitaxel) and vinca alkaloids (e.g. vinblastine, vincristine, vinorelbine). Docetaxel was originally derived from the needles of the European yew tree, Taxus baccata, and paclitaxel from the bark of the Pacific yew, Taxus brevifolia.

Historically, doctors advised cancer patients to rest during treatment. Recent research has shown, however, that physical activity can influence cancer outcomes and play a pivotal role in cancer survivorship.¹ GenesisCare considers exercise to be an important part of your treatment plan. Exercise is something you can do to help your body following a cancer diagnosis, even if you have never exercised before. Ask your specialist doctor if exercise could be right for you and how to get started. More information about exercise and cancer can be found here.

• American Cancer Society
• Cancer Council Australia
• National Cancer Institute

1. Schmitz KH, Courneya KS, Matthews C et al. for the American College of Sports Medicine. American College of Sports Medicine roundtable on exercise guidelines for cancer survivors. Med Sci Sports Exerc 2010;42:1409-1426.