Prognostic scores for patients with salivary adenoid cystic carcinoma without lymph node metastasis

Adenoid cystic carcinoma (AdCC) of salivary gland grows relatively slowly, but occasionally develops distant metastasis. Although cervical lymph node metastasis (LNM) has been reported as a strong prognostic factor, most of AdCC do not have LNM. In this study, we investigated the prognostic factors to predict disease free survival (DFS), distant metastasis free survival (DMFS), and overall survival (OS) for 175 patients surgically treated for AdCC without LNM, and developed prognostic score (PS) determined as number of positive prognostic factors. The following emerged as significant prognostic factors: positive surgical margin in DFS, pT3/4 and positive surgical margin in DMFS, and positive surgical margin and high-histological grade in OS. 10-year DFS rates were 56.4% in PS0, and 19.1% in PS1 (p < 0.0001). 10-year DMFS rates were 86.3% in PS0, 56.4% in PS1, and 30.7% in PS2 (p < 0.0001). 10-year OS rates were 100% in PS0, 73.3% in PS1, and 38.8% in PS2 (p < 0.0001).

Automated summary

Adenoid cystic carcinoma (AdCC) of salivary gland grows slowly but can develop distant metastasis. This study investigated prognostic factors in predicting disease free survival (DFS), distant metastasis free survival (DMFS), and overall survival (OS) in surgically treated AdCC patients without cervical lymph node metastasis (LNM). Positive surgical margin, pT3/4 stage, and high-histological grade were identified as significant prognostic factors. The prognostic score (PS) based on the number of positive prognostic factors showed significant differences in 10-year DFS, DMFS, and OS rates.