Local failure in resected N1 lung cancer: implications for adjuvant therapy.

PURPOSE: To evaluate actuarial rates of local failure in patients with pathologic N1 non-small-cell lung cancer and to identify clinical and pathologic factors associated with an increased risk of local failure after resection.

METHODS AND MATERIALS: All patients who underwent surgery for non-small-cell lung cancer with pathologically confirmed N1 disease at Duke University Medical Center from 1995-2008 were identified. Patients receiving any preoperative therapy or postoperative radiotherapy or with positive surgical margins were excluded. Local failure was defined as disease recurrence within the ipsilateral hilum, mediastinum, or bronchial stump/staple line. Actuarial rates of local failure were calculated with the Kaplan-Meier method. A Cox multivariate analysis was used to identify factors independently associated with a higher risk of local recurrence.

RESULTS: Among 1,559 patients who underwent surgery during the time interval, 198 met the inclusion criteria. Of these patients, 50 (25%) received adjuvant chemotherapy. Actuarial (5-year) rates of local failure, distant failure, and overall survival were 40%, 55%, and 33%, respectively. On multivariate analysis, factors associated with an increased risk of local failure included a video-assisted thoracoscopic surgery approach (hazard ratio [HR], 2.5; p = 0.01), visceral pleural invasion (HR, 2.1; p = 0.04), and increasing number of positive N1 lymph nodes (HR, 1.3 per involved lymph node; p = 0.02). Chemotherapy was associated with a trend toward decreased risk of local failure that was not statistically significant (HR, 0.61; p = 0.2).

CONCLUSIONS: Actuarial rates of local failure in pN1 disease are high. Further investigation of conformal postoperative radiotherapy may be warranted.