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(Drug information on topotecan) (Hycamtin) in recurrent or metastatic squamous cell head/neck cancer was similarly disappointing and did not even stabilize disease, Dr. Murphy said.
Irinotecan(Drug information on 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.