Neoadjuvant therapy for organ preservation in head and neck cancer.

OBJECTIVES/HYPOTHESIS: We designed two sequential trials of induction chemotherapy followed by definitive radiation in patients with potentially resectable head and neck cancer to determine whether organ preservation is feasible without apparent compromise of survival Study Design Both trials were Phase II studies. METHODS: Two clinical trials were conducted sequentially at the University of Michigan. Fifty-two patients enrolled in the first study and were treated with a planned three cycles of carboplatin and 5-fluorouracil. Patients who achieved at least 50% reduction in the size of the primary tumor received definitive radiation therapy, to a dose of 6600 to 7380 cGy. Patients with minimal response or progression had immediate salvage surgery. Thirty-seven patients enrolled in the second trial, in which the chemotherapy consisted of carboplatin, 5-fluororuracil, and leukovorin. Responders were treated with accelerated radiation therapy, to a total dose of 7120 cGy delivered in 41 fractions over 5.5 weeks. RESULTS: Toxicity and response were similar in both trials; therefore, the results are reported first separately and then combined for all 89 patients. Tumor sites included: oropharynx, 55 patients; hypopharynx, 34 patients. Eighty-three percent of patients tolerated all three cycles of chemotherapy and toxicity was mild. Response to chemotherapy was: 48% complete response at the primary tumor site, and 34% partial response at the primary tumor site. Initial organ preservation at individual tumor sites was: oropharynx, 58%; hypopharynx, 59%. Median survival was 28 months, and survival at 3 and 5 years was 40% and 24%, respectively. CONCLUSIONS: These two regimens were well tolerated, and survival did not appear to be compromised by organ preservation treatment compared with historical controls. This approach warrants further investigation, particularly in those patients for whom surgery could be functionally debilitating.

Effect of dietary vitamin A or N-acetylcysteine on ethylnitrosourea-induced rat gliomas.

It is our hypothesis that low grade gliomas are the glial counterparts of other precancerous lesions such as colon polyps and, therefore, suitable targets for chemoprevention. Steps in the molecular progression of gliomas have been described, indicating that an accumulation of abnormalities is required for progression to a high grade and interruption of this progression might be possible. An animal model of chemical glial carcinogenesis was used to test this hypothesis. Pregnant rats were injected intravenously with ENU (ethylnitrosourea) on the 18th day of gestation to induce gliomas in the offspring, which were randomized to receive control diet, diet supplemented with vitamin A palmitate, or diet supplemented with N-acetylcysteine. Animals exposed to ENU and receiving a control diet developed brain tumors and had a shortened life expectancy compared with rats unexposed to ENU. The animals treated with NAC showed no statistically significant delay in the time to tumor and no change in the histologic grade of the tumors when compared with animals receiving control diet, but the time to death from any cause of NAC treated animals differed significantly from untreated animals. Animals receiving high dose VA had statistically significantly prolonged time to tumor, survived significantly longer than untreated animals, but had no reduction in the total number of tumors or change in the histologic grade of their tumors. The theoretical basis of these results is likely due to the putative mechanism of action of these agents. These data indicate that glioma chemoprevention is possible and deserves further exploration.