| Trastuzumab and chemotherapy in advanced breast cancer after the failure of one earlier combination
While there is some evidence from retrospective trials reporting a
benefit from continued trastuzumab treatment beyond disease progression, a
discontinuation after disease progression is still standard of care. Though our study is limited by the small number of patients included, we
are able to strengthen this evidence. The reported decline in response
rates from 42.6% in first line treatment to 30% in beyond second line
compares to the expected drop of response rates with every further line of
chemotherapy or endocrine therapy in palliative treatment. Stable disease
and objective response combined, clinical benefit rates were 85.2% in
first line, 68.5% in second line and 58.3% in beyond second line. As some
other groups, we believe this to be the more significant parameter in
judging the efficacy of palliative treatment, as a stabilisation of the
disease without excessive toxicity often appears more important than
objective remission. The high clinical benefit rate of nearly 60% even
beyond second line must be seen as a clear sign of a benefit that most
patients gain from treatment continuation. Of special interest is the fact, that we did not find a statistical
significant difference in time to tumour progression (TTP) between first line, second line and beyond
second line trastuzumab based combinations. Although we rather expected to
observe a shortening of time to disease progression with every further
line of therapy, we believe this to be another sign of a potential benefit
from continued combination treatment. As median overall survival was not
yet reached, we are sure that our survival data will be well beyond the
median 25.4 months presented in the trastuzumab pivotal trial. These
results are intriguing and somewhat unexpected, but still the necessity
for larger, especially randomised, trials remains.
Rupert Bartsch Department of Internal Medicine I, Division of Oncology, Medical University of Vienna, Vienna, Austria
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