Breast cancer is not a homogenious disease, but consists rather of many different biological subgroups.
An important criterion to decide whether an adjuvant chemotherapy is indicated or not, derives from the results of the examinations of the tumor tissue in the laboratory. These results will inform us about the degree of hormone dependency of the disease: largely, only partly, or not at all dependent on the sexual hormones estrogen and progesterone.
A further examination, namely if the factor HER2 is overactive, also contributes to the decision whether a chemotherapy is indicated to treat the illness.
The risk of relapse also plays a role in deciding whether a chemotherapy is recommendable, because, in larger tumors there apparently exists a sufficiently big proportion of cancerous cells that act aggressively, to make a chemotherapy appear indicated.
In summary, it may be said that women with small or medium sized tumors, which in laboratory tests show a clear hormone dependence, usually are treated with anti-hormone therapy. The bigger the uncertainty concerning the hormone dependence of the tumor growth, the more an additional chemotherapy is recommended. For women with tumors that bear no or only little chance to profit from an antihormone therapy, a chemotherapy is to be recommended – in case of an increased risk of relapse - an intense one.
The question, whether a chemotherapy is to be carried out, which kind of chemotherapy, and for how long, has to be discussed by a particularly trained specialist - usually a medical oncologist with special expertise in breast cancer - with each patient individually.
The basis for this talk are the results of the tumor examinations, which have to be carried out under quality control, and the recommendations of breast cancer experts, in order to arrive at a satisfactory decision concerning the treatment. These recommendations come from medical associations or from international committees of experts. The one best known and internationally most implied recommendations are coming from the Consensus Conference of Saint Gall, which adapts its recommendations every 1 - 2 years to the latest research results.
If a patient or her relatives feel unsure, it is recommendable to ask another expert for a second opinion, in order to create clarity for the not always easy decisions in this difficult situation.
Professor Dr. Beat Thürlimann, Head of the Senology Center of Eastern Switzerland
Kantonsspital St. Gallen, CH-9007 St. Gallen
14.05.2007 bt / last update 15.05.2008