Chemotherapy medications most commonly affect the fast-dividing cells of the body, such as the bone marrow cells and the epithelial cells lining the mouth, stomach, and intestines. Chemotherapy-related toxicities can occur acutely after administration, within hours or days, or chronically, from weeks to years (Rachel, A, 2009).
Virtually all chemotherapeutic regimens can cause depression of the immune system, often by paralyzing the bone marrow and leading to a decrease of blood cells. Anemia and thrombocytopenia may require blood transfusion. In severe myelosuppression, which occurs in some regimens, almost all bone marrow stem cells, which produce white and red blood cells, are destroyed; this damage may indicate the necessity of bone marrow cell transplantation. Some people also develop diseases because of this interference with the bone marrow. Patients receiving chemotherapy are encouraged to wash their hands, avoid sick people, and take other infection-reducing steps, since they are vulnerable to systemic or localized infections. Sometimes, chemotherapy treatments are postponed because the immune system is suppressed to a critically low level (Elad, S, 2010).
Nausea, vomiting, anorexia, diarrhea, abdominal pains and constipation are common side effects of chemotherapeutic medications that kill fast-dividing cells. Malnutrition and dehydration can result when the recipient does not eat or drink enough or when the patient vomits frequently because of gastrointestinal side effects. This can lead to a rapid weight loss or, sometimes, weight gain, if the person eats too much in an effort to ease nausea or heartburn. Weight gain can also be caused by some steroid medications (Gibson, RJ, 2006). Due to immune system suppression, enterocolitis, especially “typhlitis” may be a gastrointestinal complication of chemotherapy. Typhlitis is an intestinal infection which may manifest itself through vomiting, diarrhea, distended abdomen, fever, chills, abdominal pain and tenderness, and may be a medical emergency (Keidan, RD, 1989).
Anemia can be a combined outcome caused by myelosuppressive chemotherapy. Treatments which suppress the bone marrow may cause a tendency to bleed easily and/or impaired blood cell production, leading to anemia. Such chemotherapy medications kill the rapidly dividing normal cells and can significantly reduce the number of platelets in the blood, so that patients are vulnerable to bruises and bleeding. Sometimes, chemotherapy treatments are postponed to allow the platelet count to recover (Sekhon, SS, 2006). Low physical stamina may be a consequence of the cancer or its treatment, and can last for months to years after treatment. The most common cause of easy fatigue is anemia, which can be caused by chemotherapy, radiotherapy and primary and metastatic disease (Franklin, DJ, 2006).
Chemotherapy induced nausea and vomiting are common with many treatments and some forms of cancer. Nausea and vomiting are two of the most often experienced cancer treatment related side effects for cancer patients. It has been demonstrated that people receiving chemotherapy ranked nausea and vomiting as the first and second most severe side effects, respectively. Some people who received agents causing intense nausea, postponed and even refused cancer treatment by these agents. Several classes of antiemetic drugs have been developed and commercialized, to become a nearly universal standard in chemotherapy regimens, helping to successfully manage these symptoms in many people. Effective mediation of these unpleasant and sometimes debilitating symptoms results in increased quality of life for the recipient and more efficient treatment cycles, due to fewer stoppages of treatment due to better tolerance and better overall health (Gill, P, 2006).
Hair loss can be caused by chemotherapy that kills rapidly dividing cells This is often a temporary effect; hair usually starts to regrow a few weeks after the last treatment, but sometimes with a change in color, texture, thickness or style. Severe hair loss occurs most often with drugs such as doxorubicin, paclitaxel, and cyclophosphamide. Permanent thinning or hair loss can result from some standard chemotherapy regimens. Chemotherapy induced hair loss is usually associated with the high mitotic rate of hair follicles and is more reversible than androgenic hair loss, although permanent cases can occur. Chemotherapy induces hair loss in women more often than men (Chadha, V, 2003).
Secondary malignant neoplasms can occur after effective chemotherapy or radiotherapy treatment for the primary tumor. The most common secondary neoplasia is acute myeloid leukemia, which develops primarily after treatment with alkylating agents or topoisomerase inhibitors. There was an investigation into the long-term risk of a second primary malignancy after chemotherapy for Hodgkin's lymphoma (HL) in a much larger cohort than any yet published. About 6,000 patients with HL treated with chemotherapy in Britain from 1963 to 2001 were followed, of whom 3,432 also received radiotherapy, to assess the second primary malignancy risks compared with general population-based expectations. Second malignancies occurred in 459 of them. After chemotherapy alone, there were significantly raised risks of lung cancer, non-HL and leukemia. When chemotherapy was combined with other “systemic” therapies, there were raised risks of these and several other cancers. The second cancer risk peaked at 5 to 9 years after chemotherapy alone, but remained raised for 25 years and longer after combined modalities (Swerdlow, AJ, 2011). The survival of breast cancer patients with a second primary malignancy and the evaluation of the impact of chemotherapy on the risk of different cancer sites were explored. The incidence of a second primary cancer for all sites was significantly higher in breast cancer patients. Chemotherapy was associated with increased incidences for all sites, except lymphoma, myeloma, and chronic lymphocytic leukemia. It was concluded that female breast cancer patients showed a higher incidence of a second primary malignancy, which was associated with a poorer prognosis and that the chemotherapy benefits should be weighed against the risks of a second primary malignancy (Wei, JL, 2019).