Effective Radiotherapy in Tracheobronchial Adenoid Cystic Carcinoma With Positive Surgical Margin.

Background: The study aimed to evaluate the role of postoperative radiotherapy (PORT) in the treatment of trachea and main bronchus adenoid cystic carcinoma (ACC) with a positive surgical margin.

Methods: Patients with pathologically confirmed trachea or main bronchus ACC operated on at Shanghai Chest Hospital were enrolled. Survival, univariate, and multivariate analyses were performed. The χ test was applied to analyze the failure patterns among different groups (R0/0: negative margin resection without PORT; R1/0: positive margin resection without PORT; R1/1: positive margin resection with PORT).

Results: From January 2001 to December 2014, 77 patients were deemed eligible for the study. Pairwise comparisons showed that the overall survival rate of group R1/1 was comparable to that of group R0/0 (P = .438), and significantly longer than the rate of group R1/0 (P = .032). Additionally, the local disease-free survival rate of group R1/1 was much higher than that of group R0/0 (P = .023) and R1/0 (P = .001). Cox multivariate analysis identified the radiologic feature (P = .012) and PORT (P = .006) as significantly favorable prognostic factors for locoregional disease-free survival. By contrast, for overall survival, PORT (P = .032) was the only corresponding variable identified by univariate analysis. Furthermore, PORT significantly decreased the locoregional recurrence rate (P = .002) but not distant metastases (P > .999).

Conclusions: PORT helped patients with tracheobronchial ACC and microscopic positive surgical margins to achieve a similar outcome as patients with complete resection. R0 resection may not be necessary for tracheobronchial ACC if it is difficult to be completely resected.