Chemotherapy can be used before or after your surgery. This is determined after your consultant has discussed your treatment plan and explained the side effects to you. This treatment option uses cytotoxic drugs to destroy breast cancer cells. These anti-cancer drugs not only destroy the way cancer cells grow but also have an affect on your normal cells.
Drugs and side effects
Many different sorts of drugs may be used and they are usually given as a combination of several drugs to produce a better effect. Commonly used drugs include epirubicin, flurouracil and docetaxel.
Side effects include tiredness, nausea and vomiting, sore mouth, hair loss and effects on the nerves of the hands and feet (peripheral neuropathy). Different people will react to chemotherapy in different ways. Some people may have very few side effects whilst others feel much worse.
Although the side effects can be unpleasant they are often well controlled with other tablets and are short lived getting better when the treatment has finished.
Cancer cells have all sorts of molecules on their surface, many of which are what are called “receptors”. They pick up molecules from the blood or the fluid around the cells and as they do so they get activated or turned on. Once a receptor is turned on in this way it sends a message into the cell where it can produce various effects such as telling the cell to grow and divide. In about one third of cancer cells a receptor called the epidermal growth factor receptor is turned on by mistake, allowing the cell to grow in an uncontrolled way.
Herceptin, another type of chemotherapy that comes under the “molecular treatments”, sticks to this abnormally active receptor and turns it off and kills the cancer cell. Tamoxifen is also a type of molecular treatment as it acts on the oestrogen receptor on the cell in a similar way.
A newer class of molecular treatments involves drugs called PARP inhibitors. These may be useful in breast cancers that are not sensitive to tamoxifen or herceptin or in those cancers due to an abnormal gene that runs in the family (the so-called breast cancer genes, BRCA1 or BRCA2). Much research is going on to try and identify more of these types of treatment for breast cancer.
As mentioned before it is possible to use chemotherapy before surgery. This is sometimes called neo-adjuvant therapy, or simply pre-operative chemotherapy. The aim is to shrink a large cancer (which would normally require a mastectomy) to a smaller lump which can be treated by wide local excision.
The advantage of this is that you can actually see the chemotherapy work as the lump gets smaller and you know that you are having the correct combination of drugs. Sometimes, if the lump does not shrink, you will be given a different combination of drugs.
Occasionally chemotherapy will not shrink the lump and a mastectomy will still be needed, but usually this works very well.
Sometimes the cancer can be too small to feel after the chemotherapy has finished. For this reason you will usually have a tiny metal marker clip placed into the cancer after the first or second cycle of chemotherapy. This is done with local anaesthetic and usually using an ultrasound scanner.