The natural history of carcinoma in situ involving bronchial resection margins.

STUDY OBJECTIVES Microscopic residual disease in the bronchial resection margins after surgical resection of lung cancer is rare, and its clinical significance remains unsettled. We studied the natural history of patients with carcinoma in situ (CIS) at their bronchial resection margins to focus on the issue of stump recurrence. METHODS Eleven individuals who had undergone radical surgery for N0M0 lung tumors were found to have CIS at the bronchial resection margins. All of the resection specimens were reviewed with respect to the pattern of CIS extension and reclassified as follows: superficial CIS, involving surface epithelium only (CIS-S), CIS extending into the submucosal gland ducts but not deeper (CIS-D), and CIS extending into submucosal gland acini (CIS-A). Patients were followed using autofluorescence bronchoscopy and high-resolution computer tomography. Clinical parameters and the local extent of CIS at histology review were correlated with outcome. RESULTS Median follow-up was 35 months (range, 15 to 89). Histology review showed two CIS-S cases, six CIS-D cases, and three CIS-A cases. All of the patients with CIS-A developed stump recurrences in contrast with those with only CIS-S. Three patients with CIS-D have developed metachronous primaries in the contralateral lung, whereas the stump region remained free of tumor. CONCLUSIONS The presence of CIS in the bronchial resection margin after resection of lung cancers is associated with stump recurrences. Although absolute numbers are too small for firm conclusions, our data suggest that those with deep glandular extension of CIS bear the highest risk of early recurrence. However, the development of new primaries away from the stump region and the possible development of distant disease are equally relevant considerations with respect to the choice of additional therapy.