Lung metastasectomy in adenoid cystic cancer: Is it worth it?

Background And Purpose: Adenoid cystic carcinoma (ACC) of salivary glands is characterized by long-term distant metastasis, most commonly in lungs. No agreement has been reached about the role of surgical treatment of pulmonary lesions. We evaluated the long-term results of lung metastasectomy for ACC in order to identify factors that should be taken into account in selecting patients eligible for surgery and treatment planning.

Patients And Methods: A retrospective study was conducted on 109 patients selected from our institutional experience and from the International Registry of Lung Metastases. Survival was calculated by Kaplan-Meier estimate and prognostic factors endowed with a predictive power for most other metastatic cancers were investigated.

Results: The cumulative survival was 66.8% at 5years and 40.5% at 10years. In patients with a disease-free interval (DFI) greater than 36months, the overall survival was 76.5% at 5years. Survival in case of complete surgical resection was 69.5% at 5years. Multivariate analysis confirmed DFI and completeness of resection resulted in the best prognostic variables.

Discussion: Lung metastasectomy should be considered as a therapeutic option to achieve local control of disease when 2 conditions are met: (1) complete surgical resection is feasible and (2) the time to pulmonary relapse after primary tumor treatment is greater than 36months. Symptomatic benefits of an incomplete lung resection in slow-growing tumors such as ACC remain uncertain. The turning point in the management of disseminated cancers will be clarified with biological profiling of ACC and the development of targeted therapies.