Prognostic value of pathologic characteristics and resection margins in tracheal adenoid cystic carcinoma

Objective: We investigate the influence of tumour and resection characteristics on survival in adenoid cystic carcinoma (ACC) of the trachea.

Methods: A retrospective study of 12 laryngotracheal, 58 tracheal and 38 carinal resections for primary ACC in 108 consecutive operative survivors between 1962 and 2007 was conducted. Postoperative radiotherapy was administered to 82% of patients (89/108). Depth of invasion, extramural extent, organ invasion, perineural growth, margin status and lymph node involvement were described.

Results: The tumour was intramural in 15% (16/108), extramural in 85% (92/108) and invaded adjacent organs in 20% (22/108). Airway margins were grossly positive in 9 (8%), microscopically positive in 59 (55%) and negative in 40 (37%) of 108 resections. Adventitial (radial) margins of transmural sections were grossly positive in 3 (3%), microscopically positive in 95 (88%) and negative in 10 (9%) cases. Perineural growth was present in 37 (34%) and absent in 12 (11%); it was not observed in 59 (55%) cases. Lymph nodes were positive in 16 (15%) and negative in 45 (42%) cases; it was not sampled in 47 (44%) cases. Median overall survival (OS) and disease-free survival (DFS) for the entire group were 17.7 and 10.2 years, respectively. OS was longer after resection with: negative airway margins (20.4 vs 13.3 years, P=0.028) and negative radial margins (21.7 vs 13.3 years, P=0.050); absence of extramural disease (21.7 vs 13.3 years, P=0.007), perineural growth (22.8 vs 7.5 years, P=0.011) or lymph node metastases (16.8 vs 6.1 years, P=0.017). DFS was longer after resection with: negative airway margins (16.6 vs 9.3, P=0.005) and absence of extramural disease (17.9 vs 9.3 years, P=0.008), perineural growth (17.9 vs 6.6 years, P=0.033) or lymph node metastases (10.2 vs 3.0 years, P=0.005).

Conclusions: After tracheal resection for ACC, limited tumour extent and complete resection are associated with longer overall and disease-free survival. Long-term survival (>10 years), however, is also observed after tracheal resection of locally advanced ACC.