1.What is chemotherapy? Chemotherapy is the abbreviation of chemotherapy, which is the main means of clinical treatment for malignant tumors. Chemotherapy in a broad sense includes chemotherapy applied to various diseases, while chemotherapy in a narrow sense only refers to chemotherapy for tumors. 2.What are the common chemotherapeutic drugs? According to the different mechanisms of action of chemotherapeutic drugs, chemical drugs with efficacy in human cancer can be broadly classified into six categories: (1) platinum drugs: cisplatin, carboplatin and oxaliplatin, etc.; (2) anti-metabolic drugs: fluorouracil, gemcitabine and capecitabine, etc.; (3) anti-microtubule drugs: paclitaxel/vincristine, hypertrigonide, etc.; (4) alkyl [hydrocarbon] agents: a very strong compound that can be used with (4) alkyl [hydrocarbon] agents: are very strong compounds that can bind to a variety of organic substances in cells such as DNA, RNA or proteins), so that these biochemical substances important to life cannot be metabolized properly. (5) cytotoxic antibiotics: bleomycin/scramycin, actinomycin D/reinomycin, adriamycin, etc.; (6) topoisomerase I/II inhibitors: irinotecan, etoposide/pedicillin, etc. While these anti-cancer drugs kill cancer cells, they also produce different degrees of toxicity to normal human cells. In order to reduce toxicity and avoid drug resistance, combined chemotherapy is usually used. 3.Cycle and course of chemotherapy The correct calculation method for the number of cycles or course of chemotherapy is: from the first day of drug administration to 21 or 28 days, i.e. 3 to 4 weeks, it is called a cycle. However, some chemotherapy drugs suppress the bone marrow later and recover more slowly, so individual regimens require 6 weeks to be considered a cycle. Some tumors require 4-6 cycles of chemotherapy to be considered as a course of treatment. The purpose is to restore or rebuild the immune function of the patient’s organism, so that the patient’s organ functions can be fully regulated, and the doctor will also advise the patient to use some drugs or nutritional medicines that can improve the immune function during this period. If the condition requires, then enter the next course of chemotherapy. 4, in the process of chemotherapy can take other drugs pharmacological research shows that some drugs can be used in combination with certain drugs to achieve the beneficial effects of enhanced effectiveness and (or) reduced toxicity, while the combination with other drugs will lead to a decrease in efficacy and (or) increased toxicity. This type of phenomenon is called drug interactions. Examples of such interactions are not uncommon in clinical chemotherapy for oncology. For example, the efficacy of cisplatin can be ensured by enhancing diuresis through massive infusion of fluids and diuretics to reduce the nephrotoxicity of cisplatin. On the contrary, when antibiotics are needed for tumor patients treated with cisplatin, aminoglycoside (such as gentamicin, kanamycin, amikacin) antibiotics should not be given, otherwise the nephrotoxicity of cisplatin can be significantly enhanced and even cause renal failure. Another example is a commonly used drug for the treatment of Hodgkin’s lymphoma called procarbazine (methylbenzylhydrazine), which has an inhibitory effect on monoamine oxidase in the human body and can hinder the detoxification of monoamines. Thus, amphetamines and certain antidepressants should not be used when procarbazine is taken. It is also not advisable to consume tyramine-rich foods such as bananas at the same time, as this may cause adverse reactions such as increased blood pressure and excessive central excitation. Some antineoplastic drugs are excreted in urine. The acidity and alkalinity of urine will affect the process of drug excretion. After tumor chemotherapy, if the tumor is sensitive to the drug, the efficacy is significant, and there can be a significant increase of uric acid excretion when the tumor tissue is heavily necrotic and disintegrating. Under these circumstances, urine with significant acidity may cause crystallization of antitumor drugs (or metabolites) or uric acid, resulting in impaired renal function or increased drug toxicity, which may lead to life-threatening consequences of acute renal failure in severe cases. This type of situation also deserves attention. In summary, chemotherapy drugs can be used with certain drugs, but must be used reasonably under the guidance of a doctor. 5.Evaluation of chemotherapy effect Judging the response of tumor to chemotherapy is the main index to judge the prognosis of patients. The effectiveness of chemotherapy is mainly judged from the following aspects: (1) Clinical manifestations: local pain is reduced or disappeared; tumor surface skin temperature decreases, edema subsides, texture becomes hard and venous anger is reduced; tumor volume becomes smaller and adjacent joint mobility increases. (2) Blood biochemical and tumor marker indexes: alkaline phosphatase, lactate dehydrogenase, etc. The elevated tumor markers drop to normal. (3) Imaging: CT/MRI showed that the tumor scope was reduced, soft tissue edema subsided, calcification or ossification appeared at the tumor edge; arteriogram showed a significant reduction of tumor vessels. (4) Pathological assessment: comparing with biopsy section before chemotherapy, the tumor cell necrosis rate after chemotherapy is the most accurate index to judge the effect of chemotherapy and the most reliable index to judge the prognosis. Pathological sampling should be comprehensive, with at least 20 or more tissue blocks, which should include upper and lower bone marrow cavity, residual cortical bone, adjacent articular cartilage, surrounding soft tissues, especially soft tissues around tumor necrosis foci, and finally make a comprehensive judgment by integrating the pathological diagnosis of each slice. At present, the tumor necrosis rate is divided into two levels: good response and poor response. If the tumor necrosis rate is more than 90%, the response is good, and the original chemotherapy regimen can be continued; if the tumor necrosis rate is less than 90%, the chemotherapy regimen should be changed by adding new drugs or increasing the drug dose. 6.Side effects of chemotherapy drugs and how to deal with them The main cause of side effects of chemotherapy drugs is the lack of selectivity to kill tumor cells. While killing cancer cells, they also damage the hematopoietic system and gastrointestinal system. Some drugs have obvious toxicity to heart and liver, and chemotherapy can also produce delayed or distant side effects. The most common side effects of chemotherapy drugs are in the gastrointestinal tract, oral cavity, bone marrow, hair, skin, and reproductive system (ovaries and testes). When side effects occur, they should be managed appropriately to reduce or alleviate symptoms. Once chemotherapy is stopped, the side effects will gradually disappear. Specific methods are: (1) gastrointestinal side effects: when there is nausea, vomiting, first of all, adjust the diet, eat less and more meals, do not eat sweets, oily or fried food; do not drink water and soup when eating; eat dry food such as toast or cookies is not easy to regurgitate; chew and swallow slowly when eating; each chemotherapy before the amount of food should be small. If nausea and vomiting persist, treat with medication. If you have diarrhea or constipation, it is advisable to regulate dietary treatment and seek medical help if necessary. (2) Side effects of the oral cavity; if dry mouth symptoms are obvious, eat moist foods such as fruits and drink plenty of water; for a dry and sore throat, eat soft, cool, non-irritating foods; when oral inflammation occurs, pay attention to oral care. When there is infection in the mouth, use 3% NaHCO3 (soda) to rinse the mouth. (3) Side effects of bone marrow: One of the more serious side effects of chemotherapy for malignant tumors is bone marrow suppression. Platelets drop, and white blood cells drop more significantly. When the white blood cell drops to 1.0×109 /L, take protective isolation measures, ask the patient to be less active, reduce visits, prevent cross-infection, and give leukocyte-raising drug treatment. (4) Side effects of hair: Hair follicle cells are sensitive to chemotherapy drugs. Therefore, hair and body hair are often lost during chemotherapy. This reaction is mostly temporary. The hair often grows back after stopping the drug, and some even grow out during the treatment, so no special treatment is necessary. (5) Side effects of skin: Rash or dry itchy skin may occur during chemotherapy. For dry skin, use more emollient moisturizers to keep it moist. (6) Side effects on ovaries and testicles: Irregular menstruation or menopause often occurs during chemotherapy. Male fertility may be permanently lost due to chemotherapy. Sexual function and libido can be affected for both male and female patients.