Consensus conference. Adjuvant chemotherapy for breast cancer.
In 1985, breast cancer will be diagnosed in approximately 120,000 women; in 90% of these women, the disease will apparently be limited to the breast and axillary lymph nodes. Despite advances in early diagnosis and primary treatment with surgery, radiation therapy, or both, more than a third of these patients will develop systemic disease and ultimately die. In the broadest sense, all of these patients are potential candidates for some form of systemic adjuvant therapy. Adjuvant therapy of breast cancer involves the use of cytotoxic drugs or endocrine therapy after definitive primary therapy. The rationale is to eradicate occult metastatic disease that otherwise would be fatal. The goal of adjuvant therapy is to significantly prolong survival, while maintaining an acceptable quality of life. Three measures are important in evaluating whether this goal is met by specific treatments: 1. The effect of therapy on overall survival: the length of time a woman survives following a diagnosis of breast cancer. 2. The effect of therapy on disease-free survival: the length of time a woman remains free of any recurrence of disease. Prolonged periods of disease-free survival may be advantageous in their own right, since quality of life is likely to be better before than after relapse. There is also some evidence that longer periods of disease-free survival may translate into better overall survival rates. 3. The effect of therapy on quality of life: in choosing an adjuvant therapy program, potential benefits must be balanced against both short-term and long-term side effects. Also important are the substantial psychological, social, and economic problems women may experience as a result of treatment. An increasing number of important prognostic variables have been identified that define the natural history of breast cancer. These include well-established factors such as histological status of axillary lymph nodes, primary tumor size, steroid hormone receptors, menopausal status or age, and histopathology. Assessment of cell differentiation and proliferation, which can be determined by newer techniques, may also be significant. The pathological status of the axillary lymph nodes remains the single most important prognostic variable, and four lymph node categories have been defined (negative, one to three positive nodes, four to nine positive nodes, and ten or more positive nodes). Since definitions of menopausal status vary widely among clinical trials, age (less than 50 vs greater than or equal to 50 years) can be substituted as a prognostic variable.(ABSTRACT TRUNCATED AT 400 WORDS)