No Link Found Between Pneumonitis in Breast Cancer Patients And
Taxane-Based Chemotherapies, Radiation
Behind the Cancer Headlines®
Researchers at The University of Texas M. D. Anderson Cancer
Center have shown that breast cancer patients treated with
taxane-based chemotherapies and radiation are not
at increased risk of developing a dangerous lung condition involving the
inflammation of lung tissue,
pneumonitis, according to a study published in the Journal
of the National Cancer Institute.
These results are vitally important, says Thomas Buchholz,
M.D., the study's corresponding author, because both radiation and
taxanes-based chemotherapies, including
Taxotere
and
Taxol, have proven effective in the treatment and
improved survival of selected patients with breast cancer.
In addition, these results disprove a previous smaller study
that had suggested the dangerous correlation between
taxanes, radiation treatment and lung injury.
"We had the unique opportunity to investigate and clearly
focus on the question of whether or not
taxanes
increase radiation induced lung complications," says Buchholz, professor in the
Department of Radiation Oncology at M. D. Anderson. "Both
taxanes
and radiation therapy are critically important in the treatment of patients
whose disease has spread beyond the breast.
"The first study showed higher rates of toxicity and received
a great deal of attention within the medical community. We were concerned that
oncologists might have some reluctance in giving these appropriate treatments.
With this study, we wanted to try and determine if we could alleviate the fears
of both the physicians administering, and the patients receiving these
potentially life-saving treatments."
The research, led by
Tse-Kuan
Yu, M.D., Ph.D., a resident in radiation oncology at M. D. Anderson and the
study's principal investigator, analyzed 189 breast cancer patients who had
been enrolled in a prospective Phase III randomized trial. The patients had
received either four cycles of
paclitaxel
(Taxol) followed by four cycles of 5-flourouracil,
doxorubicin and
clyclophsphamide
(FAC) and then radiation therapy; or eight cycles of FAC followed by radiation.
The researchers were able to review chest X-rays of the women
in both groups and could directly evaluate the rates of lung injury. They
concluded that there was statistically no difference in the rate of
radiation-induced lung toxicity between the two groups of patients; 5 percent
in those treated with the
paclitaxel-FAC and radiation, compared with 4.5
percent in those treated with FAC and radiation. In addition, the researchers
reported that no patients were hospitalized and/or died as a result of
pneumonitis.
"Fortunately, we discovered that the rates of seriously
related lung injury were very, very low in both groups of patients, making us
more comfortable in using these potentially curative treatments without any
reservations," says Buchholz.
Buchholz and Yu both point out a key difference between the M.
D. Anderson research and the earlier study was that in the M. D. Anderson
study, chemotherapy and radiation were given sequentially, compared to
simultaneous delivery in the smaller study.
"It is possible that
taxanes
and radiation given simultaneously interact to cause increased lung toxicity,
but with our delivery, which is more standard practice, we did not see any
clinically-relevant damage," says Yu. "Additionally, the sequencing and
extended time between the delivery of
paclitaxel
and the radiation might be of great importance. In our study, four cycles
of
paclitaxel
and then four cycles of FAC were given, followed by surgery and then
radiation. Having the buffer window between the
Taxol
and the radiation might be, in part, cause for why we did not see any lung
injury."
SOURCES:
Journal of the National
Cancer Institute,
University of