Chemotherapy

Once cancer cells enter the circulation they can travel to all parts of the body. They continue to multiply forming new deposits of the cancer. These distant cells will not be influenced by surgery or radiotherapy directed at the breast. We need to use drugs that circulate in the blood to reach the cells. Chemotherapy drugs are cytotoxic. This means that they damage and destroy cells in various ways. Normal body cells are also affected to some extent. There is a wide range of drugs available. Experience has shown that they often work best in combination with each other as they each cause damage at different locations in the cell. They are given either by injection or as tablets. Most regimes are given in cycles that run over three or four weeks with a rest week at the end of each cycle to allow the body to recover. The medical oncologist will discuss risks and benefits of various combinations suitable for your particular situation.

Main groups of chemotherapy drugs:

Alkylating agents: Cyclophosphamide
Antimetabolites: Methotrexate and 5 Fluorouracil
Anthracyclines: Doxorubicin, Adriamycin, Epirubicin
Taxanes: Paclitaxel ,Taxotere Doxitaxel, Taxol

Some possible side effects include:

• Nausea
• Hair loss
• Bone marrow suppression
• Infection and fever
• Tiredness
• Sore mouth or throat
• Diarrhoea
• Itchy skin
• Infertility

Why do I need chemotherapy if the cancer has been removed?

Cancer starts from a single abnormal cell. It can recur from growth of just one cancer cell left in the body after treatment. We do not have tests sensitive enough to detect individual cells. The pathology report gives us a profile of your cancer. From this information we will estimate how great the chance is that some cells might have spread into the circulation. This estimate is based on the size and grade of cancer together with the lymph node information. Remember that this is a "best guess" as we cannot actually see these tiny cells. If the risk is high then a course of chemotherapy may destroy these tiny cells before they can start to grow.

One analogy that is helpful in trying to understand this concept is to think of the weeds in your garden. You might spend the entire weekend cutting, burning and carrying away piles of weeds and feel very satisfied that by Sunday evening there is not a weed in sight. But we know only too well that given some sunshine and rain within a few weeks new weeds will appear because tiny seeds have been left in the ground. We also know that spraying the garden with weed-killer will reduce this possibility and may allow us time for a round of golf in the future! Chemotherapy works like weed-killer destroying microscopic cells before they become a problem.

Chemotherapy can improve prognosis by approximately 5 - 15 % and hormonal therapy by about 10 - 20%. The oncologist will discuss how these figures relate to your particular situation.