» Advantages and effectiveness of chemotherapy in breast cancer
Advantages and effectiveness of chemotherapy in breast cancer
The advantages of chemotherapy
The great advantage of chemotherapy over other methods of cancer treatment is that chemotherapy drugs injected directly into the blood. Surgery or radiotherapy, which are local methods often can not fully cope with all the cancer cells because of their impact sent one particular area of the body. At the same time from the primary tumor can be separated, some cancer cells that are carried by blood flow to different areas of the body. There, they may develop - this is metastasis or tumor recurrence.
Chemotherapy drugs circulate in the blood in the same way, so they can hit those separated the tumor cells in any part of the body. Treatment usually lasts from one to several days, then make a break for a few weeks. At this time the restored normal cells, whereas cancer cells are recovered only slightly.
Subsequent cycles of drug treatment aimed at the further destruction of cancer cells while normal cells are continuously restored.
The effectiveness of chemotherapy
Some types of cancer can be cured only with chemotherapy. However, for most cancers is not yet possible, and drug treatment in such cases is carried out in order to control the disease and its containment, as well as to relieve the symptoms. The main reason that explains why methods using chemotherapy can not cure most cancers, is that either the cancer cells become resistant to drugs, or they have a partial or total resistance to them from the beginning.
For example, if a tumor 99% of the cells sensitive to drugs, chemotherapy will eliminate 99% of the tumor, but has no effect on the remaining 1% of the cells, which will continue to grow. Resistance to therapeutic drugs and incomplete destruction of cancer cells are the major obstacles to more effective treatments, and were the subject of intense research. Cancer cells become resistant to a particular drug through the development of biochemical processes to overcome the damage to the cells with this drug.
One way of solving this problem is to assign several different chemotherapeutic agents, each of which is in its own way has a devastating effect on cancer cells.
The development of several mechanisms to protect cells more difficult, so the probability of complete tumor destruction increases. This method of chemotherapy led to significant improvement in cure rates for certain types of cancer.
Another way to overcome resistance is to appoint a significantly higher doses of chemotherapy. But in this case another problem arises - such high doses to cause serious harm to healthy cells, especially cells in the bone marrow that are responsible for blood. Such high doses are justified only in cases where the possible bone marrow transplant or stem cells. The more the tumor is larger, the probability of its resistance to chemotherapy drugs more. Therefore, if the primary tumor is removed surgically, and there is a danger that a small amount of cancer cells have spread to other parts of the body, in order to avoid relapse when treatment is more difficult to perform, immediately after the operation can begin chemotherapy to destroy any remaining cancer cells.