<unk> utic techniques have a range of side effects that depend on the type of medications used. The most<unk> ommon medications affect mainly the fast-dividing<unk> ells of the body, such as blood<unk> ells and the<unk> ells lining the mouth, stomach, and intestines.<unk> -related toxicities<unk> an occur acutely after administration, within hours or days, or<unk> hronically, from weeks to years. In many<unk> ases, an increase in tolerability/reduction in side effects and enhanced therapeutic efficacy through short-term fasting in the days of therapy was observed both in human and in animal experiments. Immunosuppression and myelosuppression Virtually all<unk> utic regimens<unk> an<unk> ause depression of the immune system, often by paralysing the bone marrow and leading to a decrease of white blood<unk> ells, red blood<unk> ells, and platelets. Anemia and thrombocytopenia may require blood transfusion. Neutropenia (a decrease of the neutrophil granulocyte<unk> ount below 0.5 x 109/litre)<unk> an be improved with synthetic G-CSF (granulocyte-colony-stimulating factor, e.g., filgrastim, lenograstim). In very severe myelosuppression, which occurs in some regimens, almost all the bone marrow stem<unk> ells <unk> ells that produce white and red blood<unk> ells) are destroyed, meaning allogenic or autologous bone marrow<unk> ell transplants are necessary. (In autologous BMTs,<unk> ells are removed from the person before the treatment, multiplied and then re-injected afterward; in allogenic BMTs, the source is a donor.) However, some people still develop diseases because of this interference with bone marrow. Although people receiving<unk>  are encouraged to wash their hands, avoid sick people, and take other infection-reducing steps, about 85% of infections are due to naturally occurring microorganisms in the person's own gastrointestinal tract (including oral<unk> avity) and skin. This may manifest as systemic infections, such as sepsis, or as localized outbreaks, such as Herpes simplex, shingles, or other members of the Herpesviridea. The risk of illness and death<unk> an be reduced by taking<unk> ommon antibiotics such as quinolones or trimethoprim/sulfamethoxazole before any fever or sign of infection appears. Quinolones show effective prophylaxis mainly with hematological<unk> ancer. However, in general, for every five people who are immunosuppressed following<unk>  who take an antibiotic, one fever<unk> an be prevented; for every 34 who take an antibiotic, one death<unk> an be prevented. Sometimes,<unk>  treatments are postponed because the immune system is suppressed to a<unk> ritically low level. In Japan, the government has approved the use of some medicinal mushrooms like Trametes versicolor, to<unk> ounteract depression of the immune system in people undergoing<unk> . Trilaciclib is an inhibitor of<unk> yclin-dependent kinase 4/6 approved for the prevention of myelosuppression<unk> aused by<unk> . The drug is given before<unk>  to protect bone marrow function. Neutropenic enterocolitis Due to immune system suppression, neutropenic enterocolitis (typhlitis) is a "life-threatening gastrointestinal<unk> omplication of<unk> ." Typhlitis is an intestinal infection which may manifest itself through symptoms including nausea, vomiting, diarrhea, a distended abdomen, fever,<unk> hills, or abdominal pain and tenderness. Typhlitis is a medical emergency. It has a very poor prognosis and is often fatal unless promptly recognized and aggressively treated. Successful treatment hinges on early diagnosis provided by a high index of suspicion and the use of<unk> T<unk> anning, nonoperative treatment for uncomplicated<unk> ases, and sometimes elective right hemicolectomy to prevent recurrence. Gastrointestinal distress Nausea, vomiting, anorexia, diarrhoea, abdominal<unk> ramps, and<unk> onstipation are<unk> ommon side-effects of<unk> utic medications that kill fast-dividing<unk> ells. Malnutrition and dehydration<unk> an result when the recipient does not eat or drink enough, or when the person vomits frequently, because of gastrointestinal damage. This<unk> an result in rapid weight loss, or occasionally in weight gain, if the person eats too much in an effort to allay nausea or heartburn. Weight gain<unk> an also be<unk> aused by some steroid medications. These side-effects<unk> an frequently be reduced or eliminated with antiemetic drugs. Low-certainty evidence also suggests that probiotics may have a preventative and treatment effect of diarrhoea related to<unk>  alone and with radiotherapy. However, a high index of suspicion is appropriate, since diarrhea and bloating are also symptoms of typhlitis, a very serious and potentially life-threatening medical emergency that requires immediate treatment. Anemia Anemia<unk> an be a<unk> ombined outcome<unk> aused by myelosuppressive<unk> , and possible<unk> ancer-related<unk> auses such as bleeding, blood<unk> ell destruction (hemolysis), hereditary disease, kidney dysfunction, nutritional deficiencies or anemia of<unk> hronic disease. Treatments to mitigate anemia include hormones to boost blood production (erythropoietin), iron supplements, and blood transfusions. Myelosuppressive therapy<unk> an<unk> ause a tendency to bleed easily, leading to anemia. Medications that kill rapidly dividing<unk> ells or blood<unk> ells<unk> an reduce the number of platelets in the blood, which<unk> an result in bruises and bleeding. Extremely low platelet<unk> ounts may be temporarily boosted through platelet transfusions and new drugs to increase platelet<unk> ounts during<unk>  are being developed. Sometimes,<unk>  treatments are postponed to allow platelet<unk> ounts to recover. Fatigue may be a<unk> onsequence of the<unk> ancer or its treatment, and<unk> an last for months to years after treatment. One physiological<unk> ause of fatigue is anemia, which<unk> an be<unk> aused by<unk> , surgery, radiotherapy, primary and metastatic disease or nutritional depletion. Aerobic exercise has been found to be beneficial in reducing fatigue in people with solid tumours. Nausea and vomiting Nausea and vomiting are two of the most feared<unk> ancer treatment-related side-effects for people with<unk> ancer and their families. In 1983,<unk> oates et al. found that people receiving<unk>  ranked nausea and vomiting as the first and second most severe side-effects, respectively. Up to 20% of people receiving highly emetogenic agents in this era postponed, or even refused potentially<unk> urative treatments.<unk> -induced nausea and vomiting <unk> INV) are<unk> ommon with many treatments and some forms of<unk> ancer. Since the 1990s, several novel<unk> lasses of antiemetics have been developed and<unk> ommercialized, becoming a nearly universal standard in<unk>  regimens, and helping to successfully manage these symptoms in many people. Effective mediation of these unpleasant and sometimes-crippling symptoms results in increased quality of life for the recipient and more efficient treatment<unk> ycles, due to less stoppage of treatment due to better tolerance and better overall health. Hair loss Hair loss (alopecia)<unk> an be<unk> aused by<unk>  that kills rapidly dividing<unk> ells; other medications may<unk> ause hair to thin. These are most often temporary effects: hair usually starts to regrow a few weeks after the last treatment, but sometimes with a<unk> hange in<unk> olor, texture, thickness or style. Sometimes hair has a tendency to<unk> url after regrowth, resulting in "chemo<unk> urls." Severe hair loss occurs most often with drugs such as doxorubicin, daunorubicin, paclitaxel, docetaxel,<unk> yclophosphamide, ifosfamide and etoposide. Permanent thinning or hair loss<unk> an result from some standard<unk>  regimens.<unk>  induced hair loss occurs by a non-androgenic mechanism, and<unk> an manifest as alopecia totalis, telogen effluvium, or less often alopecia areata. It is usually associated with systemic treatment due to the high mitotic rate of hair follicles, and more reversible than androgenic hair loss, although permanent<unk> ases<unk> an occur.<unk>  induces hair loss in women more often than men.<unk> alp<unk> ooling offers a means of preventing both permanent and temporary hair loss; however,<unk> oncerns about this method have been raised. Secondary neoplasm Development of secondary neoplasia after successful<unk>  or radiotherapy treatment<unk> an occur. The most<unk> ommon secondary neoplasm is secondary acute myeloid leukemia, which develops primarily after treatment with alkylating agents or topoisomerase inhibitors. Survivors of<unk> hildhood<unk> ancer are more than 13 times as likely to get a secondary neoplasm during the 30 years after treatment than the general population. Not all of this increase<unk> an be attributed to<unk> . Infertility Some types of<unk>  are gonadotoxic and may<unk> ause infertility.<unk> es with high risk include procarbazine and other alkylating drugs such as<unk> yclophosphamide, ifosfamide, busulfan, melphalan,<unk> hlorambucil, and<unk> hlormethine. Drugs with medium risk include doxorubicin and platinum analogs such as<unk> isplatin and<unk> arboplatin. On the other hand, therapies with low risk of gonadotoxicity include plant derivatives such as vincristine and vinblastine, antibiotics such as bleomycin and dactinomycin, and antimetabolites such as methotrexate, mercaptopurine, and 5-fluorouracil. Female infertility by<unk>  appears to be secondary to premature ovarian failure by loss of primordial follicles. This loss is not necessarily a direct effect of the<unk> utic agents, but<unk> ould be due to an increased rate of growth initiation to replace damaged developing follicles. People may<unk> hoose between several methods of fertility preservation prior to<unk> , including<unk> ryopreservation of semen, ovarian tissue, oocytes, or embryos. As more than half of<unk> ancer patients are elderly, this adverse effect is only relevant for a minority of patients. A study in France between 1999 and 2011<unk> ame to the result that embryo freezing before administration of gonadotoxic agents to females<unk> aused a delay of treatment in 34% of<unk> ases, and a live birth in 27% of surviving<unk> ases who wanted to become pregnant, with the follow-up time varying between 1 and 13 years. Potential protective or attenuating agents include GnRH analogs, where several studies have shown a protective effect in vivo in humans, but some studies show no such effect. Sphingosine-1-phosphate (S1P) has shown similar effect, but its mechanism of inhibiting the sphingomyelin apoptotic pathway may also interfere with the apoptosis action
Chemotherapy
Irradiation
Radiation
Chemoradiotherapy
Hormone therapy
Radiation therapy
Adjuvant therapy
External beam radiotherapy