[Physiopathologic knowledge and clinical practice. A case of high dose chemotherapy in breast cancer]

Breast cancer is the major cause of death from cancer in women. This causes a great activity in oncological investigation in this field. During the 80s preclinical data and retrospective analysis suggested a dose-response relationship both for adjuvant treatment and metastatic disease. Technical advances in collection and administration of peripheral stem cells and the development of hematological growth factors permitted the use, in this and other diseases, of high dose chemotherapy, usually with hematological support. All these things produced the widespread use of this technique with the only scientific support of phase II studies usually performed in only one center and with highly selected patients. Most of the randomized trials performed afterwards did not show a clinically important relationship between dose and response. This makes us think that this technique should not be used as routinary treatment. From a methodological point of view it would be interesting to investigate the evolution of this modality of treatment and why, its use has been so generalized without good quality scientifically support. This could be due to predetermined ideas in relation to what is the evolution and treatment of this disease, the neglect in the use of scientific methodology and the pressures coming from different directions trying to adopt new (and presumably better, treatments). It is evident that if most of the patients who have received high dose treatment for breast cancer had participated in randomized trials the question would probably have already been answered.