Colon Cancer Treatments Chemotherapy

Chemotherapy is the systematic use of anticancer drugs in the blood stream to destroy cancerous cells. These powerful drugs may also affect the normal healthy cells of the body.

Most colon cancer chemotherapy drugs are administered by injection directly into a vein or via a catheter for slower release of the drugs into the bloodstream. Some are given in pill form.

A combination of colon cancer chemotherapy drugs may be used to:

  • reduce the size of a malignant tumor before surgery
  • kill any cancerous cells that may remain in the body after surgery
  • control tumor growth
  • relieve symptoms of the disease
  • reduce likelihood of recurrence.

Which Patients Are Given Chemotherapy?

Current opinion differs among cancer specialists as to whether patients with Stage II colon cancer benefit from chemotherapy after surgery or not. Generally, it is only considered advisable for certain high-risk patients.

Adjuvant chemotherapy after surgery is routine for the majority of patients with Stage III colorectal cancers. It is also appropriate for patients with Stage IV malignancies as it can help to shrink the cancerous tumor, increase life expectancy, and improve the patient’s quality of life.

Colon Cancer Chemotherapy Drugs

Adjuvant chemotherapy usually involves the monthly administration, for a period of six to eight months, of one or a combination of colon cancer chemotherapy drugs.

Typically, standard adjuvant chemotherapy consists of a combination of the drugs 5- fluorouracil (5-FU) and leucovorin.

5-Flourouracil

Statistics indicate that the use of 5-FU, the chemotherapeutic agent of choice following surgery for Stage III disease, increases the likelihood of being cured. It is also used as palliative treatment in Stage IV cancer.

Leucovorin

Leucovorin is not a chemotherapeutic drug in its own right, but is often used for five consecutive days a month, in combination with other drugs to reduce the chemotherapeutic side-effects of the other drug(s).

Irinotecan

Recent clinical trials have shown that the chemotherapeutic drug irinotecan, in combination with standard 5-fluorouracil and leucovorin, increases survival rates in patients with colorectal cancer who have not responded to previous adjuvant treatment with 5-FU and leucovorin alone.

Oxaliplatin (Eloxatin®)

Eloxatinis another new drug, recently given “fast-track” approval by the Food and Drug Administration (FDA) for the treatment of advanced colorectal cancer. Clinical trials of Eloxatin have produced encouraging results with patients who fail to respond to the standard 5-fluorouracil and leucovorin chemotherapy combination.

Researchers have also found Eloxatin to be particularly effective for treating colorectal cancer patients where the disease has recurred or where initial treatment with a combination of irinotecan, 5-FU and leucovorin has failed to reduce the size of the tumor. The combination including Eloxatin has been shown to shrink tumors in some of those patients and to retard tumor re-growth in others. More research, however, is required into the long-term benefits of Eloxatin.

Side Effects

Reactions to chemotherapy may vary considerably from one individual to the next. Certain other medications can also have an impact on the severity of a patient’s reaction. It is important, therefore that the physician be made aware of any unrelated medications that the patient may be taking.

In general, however, much depends on the specific medication and the level and frequency of the dose given. Common side effects may include:

  • nausea
  • vomiting
  • temporary hair loss or thinning hair
  • anemia
  • mouth sores and ulcers
  • brittle nails
  • fatigue
  • diarrhea
  • temporary changes in skin pigmentation
  • temporary bruising
  • rash or itchy skin.

Less common side effects are infection, bleeding, sore eyes and/or blurred vision and skin sensitivity to sunlight. In addition, soreness of the palms of the hands and the soles of the feet (palmar plantar syndrome) may occur as a result of long-term use of 5- Fluorouracil.

Routine Monitoring and Support

All patients who receive chemotherapy are monitored carefully for adverse reactions to the drugs. Remedies are readily available to cope with most of the unpleasant side effects. For example, nausea and vomiting can be controlled effectively using prescription anti-nausea drugs.

In addition, the patient’s blood count is checked regularly to monitor how bone marrow function is affected, and to ensure that patients do not become anemic.

For Patients of Childbearing Age

An individual’s fertility may be adversely affected by chemotherapy. All issues relating to fertility, pregnancy and contraception should be addressed before treatment is started.