Quality of Life: Psychological Aspects of Adjuvant Therapy of Breast Cancer Adjuvant Therapies in Breast Cancer and Quality of Life: A Critical Review of the TWiST Concept

The conventional end points of any curative cancer treatment are disease- and re­ currence-free survival and overall long-term survival. It is customary to assume that any increase in the number of cured patients at 5 or 10 years justifies and compensates for all early and late side effects of treatment, not only for the cured but also for the unsuccessfully treated patients. Quality of life assessments rarely influence the evaluation of truly curative therapies. The conventional end points for the assessment of adjuvant chemotherapy are essentially the same as for curative treatment because the final aim of adjuvant therapy is an increase in cure rates. However, more than 15 years of clinical re­ search in this area have demonstrated that the truly curative effects of adjuvant chemotherapy in breast cancer are marginal and possibly limited to small sub­ groups. The main effect is on disease-free survival and much less, if at all, on over­ all survival and definitive cure rates. If adjuvant chemotherapy preponderantly increases life spent without recurrent and symptomatic disease but not the cure rate, then such treatment approaches palliative chemotherapy, and considerations which are relevant in palliative chemotherapy and relate to the quality of life become important. The main ques­ tion in palliative chemotherapy is whether palliation of disease symptoms and time without tumor progression outweighs the toxic side effects of treatment and to what extent (Brunner 1987). Analogously, in adjuvant chemotherapy of breast cancer with a very limited curative potential the question arises of whether the prolongation of the time spent without symptoms of recurrent disease for a limited number of patients compensates for the toxic side effects of all treated patients, in­ cluding those who are unsuccessfully and those who are unnecessarily treated. The assessment of toxicity and cost-benefit ratios which are quality-of-life oriented become less and less important, the higher the curative potential of a can­ cer treatment is. Short-term toxic side effects are then of little concern, and only long-term sequelae of treatment have to be considered. On the other hand, the less effective a cancer treatment is, the more important are the short-term toxic side ef­ fects and the question of their acceptability in relation to the treatment result. Late toxic events such as second neoplasias and infertility can be largely neglected. These relations are demonstrated in Fig. 1.