Polychemotherapy
Contents:
Description:
The majority of oncological diseases treat at the same time several antineoplastic means. Many polychemotherapeutic schemes were developed empirically, nevertheless almost all of them satisfy to the principles stated below:
- Each drug has to be separately active concerning this tumor. It is impossible to include inactive drugs in the scheme, hoping only for a synergism; most likely, it will lead to strengthening of side effects, without having brought any benefit.
- Drugs have to have different mechanisms of action. It is desirable that they interrupted different biochemical reactions. The drugs suppressing the same enzyme or possessing the identical mechanism of action will hardly render additional antineoplastic effect.
- To drugs there should not be a cross stability. The subneoplastic population which gained one drug resistance will hardly be steady against the others if they possess other mechanism of action.
- Drugs have to have different dozolimitiruyushchy side effects. Use of two drugs with a similar profile of toxicity in the maximum tolerable doses is accompanied by the hardest side effects.
Unfortunately, it is much more difficult to follow these principles in practice, than it seems.
One more approach to treatment of oncological diseases - high-dose chemotherapy (or a combination химио and radiation therapy) with the subsequent transplantation of marrow for hemopoiesis recovery. From tsitostatik at the same time usually use the alkylating means, in particular бусульфан and cyclophosphamide at which the dose-effect curve has rectilinear character. Similar approach allows to increase a share of the perishing tumor cells.
Autotransplantation means use of in advance prepared own stem cells of blood or marrow of the patient which are stored in the frozen state.
At allotransplantation of the patient receives marrow from the donor, compatible on HLA antigens. There are many data that at recipients of allogenic marrow also immune mechanisms participate in eradication of a malignant tumor. Specific mediators of this reaction which received the name "a transplant against a tumor" are unknown so far.
Transplantation of marrow is most effective at tumors, initially sensitive to chemotherapy, - acute leukoses, a lymphogranulomatosis, lymphoma, germinogenny tumors of a small egg. At many tumors of an epithelial origin, in particular at not small-celled cancer of a lung and a colon cancer, it is inefficient.
