An early report of a recent trial has shown that high dose chemotherapy does not improve survival in women with metastatic breast cancer (Lancet, 2000; 355: 905).
In the trial, conducted at the University of Pennsylvania Cancer Center, there was no significant difference between groups receiving standard dose compared with high dose chemotherapy either in three year survival or in the median time the disease took to progress.
Of 553 women aged between 18 and 60 with untreated metastatic breast cancer, 310 responded partially or completely to the treatment. Of these, 110 received high dose chemotherapy with stem cell rescue and 89 received conventional chemotherapy a difference that is not considered significant.
The only difference between the two groups was in the effects of the different drug dosages: the high dose group experienced a higher rate of moderate to severe (non fatal) side effects than the standard group. High dose chemotherapy was shown to simply increase side effects without any clear benefit.
These results come only a month after Werner Bezwoda, professor and author of a study of the
efficacy of high dose chemotherapy and stem cell transplants in the treatment of breast cancer, admitted falsifying his evidence.
In light of this admission, The Lancet (2000, 355: 999-1003) has published a reanalysis of some of his study data.
While the initial reports of the Bezwoda study showed significant survival advantages for women on a high dose regimen, a record review by a team of US researchers revealed serious irregularities. There were discrepancies between the recorded and presented data, the women had not signed informed consent forms to participate in the trial and there was no record of any approval of the study protocol by the appropriate committee. After the investigation, Bezwoda admitted using a control protocol that was different from that described in the presented data.
In light of these findings, the question asked in the accompanying editorial was, not surprisingly, “Where next with stem cell supported high dose therapy for breast cancer?” (Lancet, 2000; 355: 944-5).
At this time, admits the journal, there is no good evidence to justify such an aggressive regime. Instead, the editorial concluded, therapy for breast cancer must be tailored to the individual, taking into account the nature of her disease, her tolerance of therapy and her preferences.