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-Chemotherapy of malignant tumors - is the use for therapeutic purposes drugs that inhibit the proliferÐ°tion Ð¾r irreversibly damaging tumor cells. In a broad sense, this term reflects treatments of malignant neoplasms, related to the effect of pharmacological funds directly to the tumor. The most fully all Ð°sÑ€ects chemotherapy of malignant tumors reflects the term "drug therapy of tumors, implying the use of synthetic drugs substances of natural origin, antibiotics, hormones and other anticancer funds. However, both terms are acceptable
Chemotherapy of malignant tumors is an independent and promising area of oncology, the role which each year increases. This is due to significant advances in the field research and study of anticancer drugs, to clarify their pharmacokinetics and mechanism of action, as well as the prospect of a rational and purposeful their use in combination with surgery and radiation therapy. Currently, chemotherapy of malignant tumors had reached a level allows to distinguish groups of common forms of malignant tumors, which can be fundamentally healed in more than 50% of cases with a single drug method. These include lymphoma, horionkartsinoma cancer, Burkitt's tumor, germ cell testicular tumors, acute lymphoblastic leukemia in children.
In the treatment of virtually every patient with malignant
tumors considered whether to proceed
The main tasks of the medicinal methods:
â™¦ increase the frequency and duration of complete remissions;
â™¦ an increase in life expectancy;
â™¦ improve the quality of life.
Indications for the use of chemotherapy is a primary
common process and the development of disease recurrence after local
â™¦ adjuvant chemotherapy (directed at reducing the risk of
recurrence of the disease by acting on micrometastases after
surgical or radiation treatment of the primary tumor).
â™¦ neoadjuvant chemotherapy (the use of chemotherapy before surgery
or radiation therapy to reduce the size of tumor masses and subsequent evaluation of their sensitivity to cytostatic drugs used).
Neoadjuvant chemotherapy is justified:
1) better penetration of cytotoxic drugs in the intact tumor;
2) a decrease in tumor mass, allowing to reduce the amount of therapy;
3) early eradication of micrometastases;
4) the possibility of using higher doses of cytotoxic drugs;
5) assessment of individual sensitivity of tumors to cytostatic drugs,
which is important for planning further therapy.
By way of anticancer agents are following
types of chemotherapy:
1. System - is designed for general (resorptive), antitumor
effect. Drugs are introduced into the subcutaneous, intravenous, intramuscular
2. Regional, elevated concentrations of the cytostatic influence
the tumor by injection into the vessels feeding the tumor;
while limiting intake of the drug in other organs.
3. Local - the application of appropriate dosage forms on the surface
foci, the introduction of a serous cavity with effusion, intravesically
or into the spinal canal.
The most widespread systematic Combination chemotherapy.
General principles of chemotherapy
Cancer cells need to be sensitive to the cytostatic drugs used.
2. The drug must reach the tumor cells (for example, to penetrate
through the BBB with brain metastases).
3. If the drug is effective only in one phase of the cell cycle, it must
introduced so often that all tumor cells have been this phase
during his presence in the body.
4. Tumor cells must be destroyed before they become resistant
5. Combination chemotherapy more effective use of cytostatics in mono.
Modern oncology has the ever-expanding arsenal of
chemotherapeutic agents that are used with the aim of eradication
tumor tissue, or - if the optimal goal is unattainable - the maximum
reduce tumor mass, to achieve significant remission
and increase survival.
A crucial role in the effectiveness of antitumor action often
played dose chemotherapy.
When choosing drugs for chemotherapy, the following
Principles (De Vita V. et al., 1993):
1. Drugs should have a moderate or high efficiency
at a given location of the tumor.
2. In the presence of several drugs of one class, with close
efficiency, preference is given to the least toxic.
3. Using the most effective treatment and dosage.
4. Preferable to combine cytotoxic agents with different mechanisms
action and spectrum of toxicity.
5. The combination of cytotoxic drugs should be applied at regular intervals,
which should be as short as possible and to ensure recovery
Only the most sensitive organs (primarily
A crucial role in the effectiveness of antitumor action often
played dose chemotherapy. It is shown that a decrease in dose intensity
reduces the frequency of positive effect and / or overall survival in some types of cancer. The significant increase in dose in most cases impossible because of the development
adverse reactions caused by damage to normal organs
and tissues. Close conjugation of therapeutic and toxic effects is
feature of the drug therapy of malignant tumors. Low
selectivity of chemotherapy due to the fact that the progenitors of tumor
are normal cells. Most vulnerable to cytotoxic chemotherapy
reproductive organs, lymphoid tissue, hair follicles,
epithelium of the gastrointestinal tract and bone marrow.
ML Gershanovich in 1982, first published clinical classification
complications of chemotherapy of tumor diseases, which still
not lost its importance.
I. Complications associated with toxic (cytotoxic) action
1. Local irritant (non-specific action): toxic dermatitis,
inflammatory infiltrates and necrosis of subcutaneous tissue
phlebitis, aseptic cystitis and serozity (pleurisy, peritonitis, etc.).
2. System, relatively non-specific side effects: myelo-
depressed, dyspeptic syndrome, skin lesions and its appendages,
mucous membranes, impaired reproductive function.
3. System, a relatively specific side effects: neyrotok-
classical, hepatotoxic, pankreatotoksicheskoe, cardiotoxic
actions, lung, urinary tract, blood coagulation
blood system, visual system, endocrine and metabolic disorders
chromosomal abnormalities, teratogenic effects, carcinogenic
effect (the appearance of secondary tumors).
II. Complications associated with immune imbalance
1. Immunosuppressive effect: intercurrent bacterial, fungal,
viral and protozoal infections (Fig. 6.11-6.13), exacerbation of chronic
focal infection, the progression of cancer.
2. Allergic reactions: allergic dermatitis, allergic pul-
Monet, the general reaction of anaphylactic type.
3. Autoimmune reactions: leukopenia, agranulocytosis, thrombocytopenia,
hemolytic anemia, vasculitis.
III. Complications caused by intolerance to cytostatic (congenital
1. Any (unexpected) complications, but most often associated with major
cytotoxic properties of the drug (mielodepressiya, independent
on the dose, etc.).
2. Paradoxical and unusual pharmacological action of drugs
reactions (fever, etc.).
IV. Complications caused by the interaction of the body cytostatic
with other drugs (including those with other anticancer drugs)
1. Enhancing inherent cytostatic effects.
2. Unusual manifestation of cytostatic side effects due to the formation
new metabolites and other mechanisms.
3. Strengthening cytostatics toxicity of other pharmacological
Determination of the toxicity in accordance with the recommendations
WHO (1979), which described in detail the main types of collateral
action of anticancer drugs. According to terms of all the complications are divided into immediate,
immediate, delayed and delayed.
Immediate complications (vomiting, nausea, drug fever,
hypotensive syndrome, various types of allergic reactions) are observed
in the first hours after drug administration.
Surrounding side effects (mielodepressiya, dyspeptic syndrome,
neurological disorders, toxic lesions of the urinary system
pancreas, lung, myocardium, immunodepres-
Sia) manifest themselves in the process of chemotherapy more frequently by the end of treatment.
The same reaction, but are up to 6 weeks after completion of treatment,
called delayed. Regardless of the application himiopre-
Parata delayed, as a rule, liver function abnormalities,
infarction, bone marrow.
For long-term complications include those that develop within 6 -
8 weeks after completion of the course (teratogenic, carcinogenic effect).
The appearance of the immediate and delayed complications may lead to
temporary cessation of treatment, and sometimes to the abolition of the latter.
The most common for most drugs are the complications associated
with cytotoxic effects on tissues with severe proliferative
activity. Obviously, the most frequent complication during chemotherapy
is toxic leukopenia.