NASHVILLE, TennesseeHistorically, chemotherapy was
only palliative in head and neck cancers, but chemotherapy regimens
now in use actually do cure some patients, Barbara A Murphy,
MD, told a clinical investigators workshop. Dr. Murphy is
Assistant Professor of Medicine at Vanderbilt-Ingram Cancer Center in
Nashville, Tennessee. The workshop was sponsored by the University of
Texas M. D. Anderson Cancer Center and Pharmacia Oncology.
Palliation of symptoms remains an important use, but Dr. Murphy said
that single-agent chemotherapy has response rates of 15%-40% with
minimal toxicity and that combination therapy has response rates of
30%-70% with possibly better palliative effects. No randomized
controlled trial has shown a survival advantage for combination vs
single-agent therapy in head and neck cancer, she said.
Larynx preservation is an important goal in treating head and neck
cancers. Dr. Murphy said that the Veterans Administration Larynx
Preservation Trial had a 2-year survival rate of 68% in both arms and
a 64% larynx preservation rate. Chemotherapy can be utilized to
preserve organ function, she said. Concomitant
chemoradiotherapy has also produced a clinically
meaningful survival rate advantage, she added.
Metastatic Disease Trials
Trials of agents have usually been done first in patients with
metastatic disease, but Dr. Murphy said that might change, since
there are so few patients in this category eligible for trials. She
reported that 9-aminocamptothecin was not shown to be effective in
metastatic or recurrent disease. The E3393 phase II study of
topotecan (Hycamtin) in recurrent or metastatic squamous cell
head/neck cancer was similarly disappointing and did not even
stabilize disease, Dr. Murphy said.
Irinotecan (Camptosar) had more promising effects in the HN-9702
phase II trial in chemonaive patients with metastatic/recurrent
squamous carcinoma of the larynx, pharynx, or oral cavity (not
including the nasopharynx). The protocol called for treatment with
irinotecan 125 mg/m² IV weekly for 4 weeks, with treatment
repeated after a 2-week rest. This dose level proved too toxic and
was decreased to 75 mg/m². The complete plus partial response
rates totaled 26.3% with the higher dose and 14.2% with the lower
dose. The major toxicities were gastrointestinal, mainly
nausea/vomiting and diarrhea. Irinotecan has activity in
squamous carcinoma of the head and neck and was recommended for
further study, Dr. Murphy said.