Patterns of Recurrence and Overall Survival in Incidental Lung Cancer in Explanted Lungs

Recurrence and overall survival for incidental lung cancer in explanted lungs vary between different series. Recurrence patterns are also not well described. The primary objective of this study is to study the recurrence patterns and time to recurrence for various stages of lung cancer in lung transplant recipients.

A retrospective review of our institutional database was performed to identify patients who had incidental lung cancer found in transplant pneumonectomy specimens from 1990 to 2017. Demographic, radiographic, and perioperative clinical variables were collected. Time to recurrence, overall survival, and recurrence patterns were recorded. Freedom from recurrence and overall survival were estimated by using Kaplan-Meier analysis.

Thirty-one patients had unexpected malignancy and 29 patients (1.6%) had primary lung carcinoma in the explanted lung. Indication for transplantation was chronic obstructive pulmonary disease in 15 patients (48%) and interstitial lung disease for 16 patients (52%). Preoperative imaging showed indeterminate nodules in 10 patients (32%). Pathologic review showed stage I disease in 15 patients (54%), stage II disease in 10 patients (35%), and stage III disease in 2 patients (7%). Recurrence was noted in 8 patients (28%). Most patients had nodal disease (25%) or systemic recurrence (75%). All recurrences occurred within 2 years of the transplantation. For patients with stage I and II disease, freedom from recurrence at 1, 3, and 5 years was 91%, 55%, and 55%, respectively. Overall survival at 1, 3, and 5 years was 78%, 18%, and 14%, respectively.

Most recurrences occur within 2 years after transplantation and are the cause of death in these patients. Patients with nodal disease tend to have higher recurrence rates. Multidisciplinary review of abnormal radiographic findings before transplantation and close follow-up may allow for detection of undiagnosed cancers.