Therapeutic strategies for adenoid cystic carcinoma of the nasal and paranasal sinus from the long-term treatment results

This article presents long-term treatment results by analyzing 24 cases with adenoid cystic carcinoma (ACC) of the nasal and paranasal sinus treated from 1975 to 1995 at Akita University Hospital and Chiba University Hospital. The basic strategies for treatment for ACC of the nasal and paranasal sinuses are en bloc tumor resection, followed by primary reconstruction of the maxilla. Preoperative and postoperative radiation were combined. Cumulative 5-year and 10-year survival rates were 70.6% and 47.1% for maxillary sinus tumors, respectively. Cumulative 5-year and 10-year survival rates for nasal tumors were 100% and 75.0%, and those for sphenoid sinus tumors were 50.0% and 0%, respectively. The patient with ethomoid sinus who needed skull base surgery is alive at 8.1 years after therapy. Treatment results closely correlated with tumor extension. Cumulative 5-year survival rates for T2, T3 and, T4 patients with maxillary sinus tumors were 85.7%, 71.4%, and 33.3%, respectively. And cumulative 10-year survival rates for T2, T3, and T4 were 71.4%, 42.9%, and 0%, respectively. The histopathological effects of preoperative radiation were Shimosato II a in 6 out of 10 patients, II b in 2, and III in 2, respectively. Only fast neutron therapy reached Shimosato III. Two of the patients with Shimosato II a died of distant metastasis. The above data suggests that, although radiation therapy alone cannot cure tumors, preoperative full-dose radiation may prevent the development of distant metastasis if it can achieve histopathological effects of a higher classification than Shimosato II b. Because chemotherapy and radiation is not very effective on ACC, the role of skull base surgeries for nasal-paranasal sinus malignancies that invade the skull base is valuable, particularly in cases having a relatively small mass in the ethmoid sinus. (author)