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

- Delayed metastases occur in 25-50% of patients with adenoid cystic carcinoma (ACC).
- Pulmonary metastasectomy as a curative procedure in ACC should be further investigated.
- ACC has a tendency to local recurrence and long-term distant metastases.
- Lung resection for metastatic ACC is acceptable if complete resection is feasible.
- Symptomatic benefits of incomplete lung resection in ACC remain to be proven.

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