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Chemotherapy

    Chemotherapy simply means that chemical substances are used to treat a medical problem. Taking aspirin for a headache is a relatively innocuous form of chemotherapy. As applied to cancer treatment, chemotherapy involves the use of very powerful chemical substances. Over one hundred different drugs can be used, either alone or in combination. They kill normal cells in the same way they kill cancer cells because, to date, it has not been possible to develop a cancer-specific chemotherapeutic agent.
    Chemotherapy drugs act generally is killing DNA or the DNA synthesising process. Those that simple attack the DNA will affect normal cells just as much as the cancer cells. Those that focus on the synthesising process will attack all fast-dividing cells - including the cells that line the intestinal tract, blood forming and hair cells. Anyone taking on eof these agents will suffer some degree of nausea and perhaps infection. These infections can be life threatening. It is not uncommon for people undergoing chemotherapy to develop pneumonia for example - some dying as a result.
    A random sampling of the side-effects someone taking chemotherapy can expect to suffer are: mouth sores, bone marrow suppression, liver and/or kidney damage, skin darkening, nail damage, bleeding internally and externally and lowered blood calcium. Some of these are more general than others. Liver and kidney damage, along with bone marrow suppression, are the most widespread. Different agents have different effects. In addition, some, if not the majority, of chemotherapeutic agents are themselves carcinogenic - i.e. they will cause cancer in a number of cases.
    There appear to be a large number of toxic deaths associated with high-dose chemotherapy treatments. The more intractable cancers appear to be, and the more desperate researchers are to show some effect, the more likely they are to use high-dose treatment regimes. This does not benefit patients. Often the dose given is so lethal that it kills the bone marrow. This requires that patients undergo a procedure known as autologous bone marrow transplantation, in which some of their bone marrow is taken out before the chemotherapy treatments and cultivated. At the end of the treatments, this marrow is then thresplanted back into the patient. This is an expensive, high-tech and gruelling treatment, which appears to have some short-term benefits in increasing disease free periods, but no long-term benefits in terms of increased survival.

Why doesn't chemotherapy work?
    The main problem is resistance. Chemotherapy is often quite successful at first. After its use, the tumour shrinks and the chemical markers in the blood decline. These markers are indications of the cancer's presence and its degree of activity. But then, even though the drugs are still being given, there is a relapse and the cancer starts to grow again. Resistance is not only common - it is the norm. This has led doctors to use two or more chemotherapy agents in combination. Yet once resistance to one drug combination occurs, there is an increased likelihood that there will be resistance to other combinations.Cancer cells resist chemotherapy by a process known as gene amplification. This is what cancer cells do anyway - so chemotherapeutic drugs are making the cells more cancerous. The more they are attacked, the stronger they get. In addition, some chemotherapy drugs, known as alkylating agents, are recognised by the experts as causing bladder cancer and leukaemia