Radiotherapy alone or combined with surgery for adenoid cystic carcinoma of the head and neck.

BACKGROUND The purpose of this study was to analyze the results of radiotherapy (RT) alone or combined with surgery for adenoid cystic carcinoma. METHODS Between September 1966 and November 2001, 101 previously untreated patients were treated with curative intent with RT alone or combined with surgery. Follow-up ranged from 0.4 to 30.6 years (median, 6.6 years). All living patients had follow-up for at least 1 year. RESULTS The 5- and 10-year rates of local control were as follows: RT alone, 56% and 43%; surgery and RT, 94% and 91%; and overall, 77% and 69%. Multivariate analysis of local control revealed that T stage (p=.0101) and treatment group (p=.0008) significantly influenced this endpoint. The 5- and 10-year rates of distant metastases-free survival were 80% and 73%. The 5- and 10-year absolute survival rates were as follows: RT alone, 57% and 42%; surgery and RT, 77% and 55%; and overall, 68% and 49%. Multivariate analysis of absolute survival revealed that T stage (p=.0043) and clinical nerve invasion (p=.0011) significantly influenced this endpoint. The 5- and 10-year cause-specific survival rates were as follows: RT alone, 65% and 48%; surgery and RT, 81% and 71%; and overall, 74% and 61%. Multivariate analysis revealed that T stage (p=.0008) and clinical nerve invasion (p=.0005) significantly influenced cause-specific survival. CONCLUSIONS The optimal treatment for patients with adenoid cystic carcinoma is surgery and adjuvant RT. A significant proportion of patients with incompletely resectable disease are cured after RT alone. Improvements in locoregional control are offset, in part, by the relatively high incidence of distant metastases.