Surgery alone provides long-term survival rates comparable to those of surgery plus postoperative radiotherapy for patients with adenoid cystic carcinoma of the palate.

We compared the outcomes and rates of survival provided by surgery alone and surgery combined with postoperative radiotherapy for patients with adenoid cystic carcinoma of the palate (ACP), a rare, low-grade malignant tumor arising within the salivary glands. Fifty-eight patients with ACP were included in this retrospective study. ACP at stages T(1), T(2), T(3,) and T(4) was found in 11, 32, 5, and 10 patients, respectively. The patients were treated with surgery alone or underwent surgery combined with postoperative radiotherapy. The 5, 10, and 15year survival rates were 75%, 37.5%, and 25%, respectively, among the 24 patients who underwent surgery alone. These were not significantly different from the rates of 70.6%, 35.3%, and 20.8%, respectively, among the 34 patients who underwent surgery plus postoperative radiotherapy (P=0.21). The 5 and 10year survival rates were significantly greater among patients receiving ⩾60Gy of radiotherapy than those among patients receiving <60Gy of radiotherapy (83.3% and 45.8% vs. 40.0% and 10.0%, respectively) (P=0.04). ACP exhibited good long-term survival rates when treated with surgery alone. Addition of postoperative radiotherapy at doses of ⩾60Gy had no effect on survival, but postoperative radiotherapy at doses of <60Gy reduced survival. Recurrence within the palate was the main cause of treatment failure. Crown