Prognosis and risk factors for early-stage adenoid cystic carcinoma of the major salivary glands.

BACKGROUND

Adenoid cystic carcinoma (ACC) is characterized by slow growth, frequent local recurrences, and distant metastasis (DM). However, these findings frequently are reported in patients with advanced-stage tumors, but the outcomes of early-stage tumors are poorly defined. We sought to evaluate the risk factors for the development of DM in early-stage ACC.

METHODS

We retrospectively reviewed the charts of 60 patients who were diagnosed with clinical early-stage (T1-2/N0) ACC to determine the risk factors for development of DM and survival of these patients.

RESULTS

DM was detected in 12 (20%) of the patients, with a median latency of 31.5 months after diagnosis. Univariate analysis revealed that DM was associated with age ≥45 years, pathologically positive lymph nodes, extracapsular spread (ECS) from lymph nodes, high-grade histology, and solid tumor subtype. Multivariate analysis revealed solid tumor subtype and ECS to be significantly associated with DM. Disease-specific survival rates at 5 and 10 years for patients with DM were 80% and 40%, respectively, and were both 100% for patients without DM.

CONCLUSION

Although the majority of patients with clinical early-stage ACC of the major salivary glands have favorable prognosis, a significant percentage of patients will develop DM. Solid tumor subtype and nodal ECS were independent predictors of DM in early-stage ACC of major salivary glands. Other clinical and pathological variables may also contribute. These subgroups had poor overall and disease-specific survival. Such patients should be observed closely for the development of DM. Systemic therapy should be considered at the time of diagnosis.