Chemotherapy is the treatment of cancer with one or more cytotoxic anti-neoplastic drugs. An older and broader use of the word chemotherapy encompassed any chemical treatment of disease, inhibiting cells, whether they be cancerous self cells or foreign cells such as bacteria. The general concept of this treatment has been used for 70 years originating from the effects of Mustard gas in World War 1 is now a multi-billion dollar industry and the standard of care for cancer treatment.
Because cancer cells may grow and divide more rapidly than normal cells, chemotherapy is made to kill growing cells. Many normal, healthy cells also multiply quickly, and chemotherapy can affect these cells, too. This damage to normal cells causes side effects. The fast-growing, normal cells most likely to be affected are blood cells forming in the bone marrow and cells in the digestive tract (mouth, stomach, intestines, esophagus), reproductive system (sexual organs), and hair follicles. Chemo may affect cells of vital organs, such as the heart, kidney, bladder, lungs, and nervous system.
In view of the minimal impact of cytotoxic chemotherapy on 5-year survival, and the lack of any major progress over the last 20 years, it follows that the main role of cytotoxic chemotherapy is in palliation. Although for many malignancies, symptom control may occur with cytotoxic chemotherapy, this is rarely reported, and, for most patients, the survival in those who obtain a response is rarely beyond 12 months.
The introduction of cytotoxic chemotherapy for solid tumors and the establishment of the sub-specialty of medical oncology have been accepted as an advance in cancer management. However, despite the early claims of chemo as the panacea for curing all cancers, the impact of cytotoxic chemotherapy is limited to small subgroups of patients and mostly occurs in the less common malignancies.
Even so, any new chemotherapy drug is still promoted as a major breakthrough in the fight against cancer, only to be later rejected without the fanfare that accompanied its arrival. In an environment of scarce resources and cost containment, there is a need for evidence-based assessment before any new or previously accepted treatment is accepted as standard practice. To justify the continued funding and availability of drugs used in cytotoxic chemotherapy, a rigorous evaluation of the cost-effectiveness and impact on the quality of life is urgently required.
This study was presented by the Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, NSW; Department of Medical Oncology,
St Vincent’s Hospital, Sydney, NSW; Collaboration for Cancer Outcomes Research and Evaluation, Liverpool Health Service, Sydney, NSW, Australia
You may have none of these side effects or just a few. The kinds of side effects you have and how severe they are, depend on the type and dose of chemotherapy you get and how your body reacts.
Cognitive changes are sometimes related to higher-dose chemotherapy and the use of immunotherapy to boost the immune system. Those who have cancer involving the brain may also experience cognitive changes as a result of the tumor or the treatment of the tumor. While cognitive changes associated with brain surgery often occur immediately, changes associated with radiation and chemotherapy can develop more gradually over time.
Some changes after cancer are very minor and will go away. Other cognitive changes may be more noticeable and may not be reversible.