Low recurrence of lung adenoid cystic carcinoma with radiotherapy and resection

Adenoid cystic carcinoma is a rare cause of thoracic malignancy, and the prognosis may depend on the extent of surgical resection and adjuvant radiotherapy. Complete resection has low rates of local recurrence but is complicated by the involvement of central airways. Adjuvant radiotherapy is frequently recommended but unproven.

We describe the technicalities of radical resection and adjuvant radiotherapy using the primary endpoint of local recurrence and secondary endpoints of locoregional (mediastinal) recurrence and distant metastasis. Resections were classed as microscopically and macroscopically clear (R0) or only macroscopically clear (R1).

Twelve patients (eight males) diagnosed between 1999 and 2016, with an average age of 44 ± 12 years, were included. Six of these were operable (operative group), and six had non-resectable lesions (radiotherapy group). In the operative group, three had tracheal disease and three had bronchial disease. Tracheal lesions underwent excision with tracheal anastomosis (all R1 resections). Main bronchial lesions underwent complete excision via pneumonectomy (two R0 and one R1 resections). All these patients received 50-60 Gray of adjuvant radiotherapy. At an average follow-up of 6.1 ± 4.3 years, no patient had local recurrence, two had locoregional recurrence and four had distant metastasis. The radiotherapy group received 60-70 Gray as definitive therapy, and at an average follow-up of 5.4 ± 4.2 years, three had locoregional recurrence and four had distant metastasis.

Our case series consolidates evidence that early radical resection and radiotherapy is associated with a low risk of local recurrence in patients with thoracic adenoid cystic carcinoma.