E2017. Predictors of Extra-Pulmonary Metastatic Disease in Patients with Recurrent Lung Cancer
  1. Tyler Grey; McMaster University
  2. Abdullah Alabousi; St. Joseph's Healthcare Hamilton
  3. Mostafa Alabousi; McMaster University
  4. Ehsan Haider; St. Joseph's Healthcare Hamilton
Lung cancer is an aggressive malignancy that is one of the leading causes of cancer-related mortality worldwide. Its poor prognosis has been associated with late detection and high rates of recurrence (1). We sought to evaluate the imaging characteristics of lung cancer recurrence and to assess for predictors of extra-pulmonary metastatic disease in patients with recurrent disease.

Materials and Methods:
We conducted a retrospective study of all patients at our institution with lung cancer recurrence detected on post-treatment surveillance imaging between January 2014-October 2019. Research ethics board approval was obtained. Included patients underwent pre-treatment computed tomography (CT) imaging, surgical resection, and follow-up CT imaging. Pre-treatment and post-treatment imaging characteristics of the pulmonary lesions, as well as pathological findings were analyzed. Univariate logistic regression was performed to assess for potential predictors of extra-pulmonary metastatic disease. The following variables were evaluated: age, gender, size and imaging characteristics of the recurrent lesion, location of recurrence, chest wall or mediastinal invasion, lymphadenopathy, and malignancy subtype. Corresponding odds ratios (OR) and p-values were calculated. A p-value =0.05 was considered statistically significant.

A total of 76 patients were included (33 males; mean age 70.9±7.7). The primary lesions were adenocarcinoma (N=50), squamous cell carcinoma (N=21), or other (N=5). The mean number of recurrent lesions was 2.2, with a mean size of 1.7 cm (standard deviation [SD] 1.3). The mean time to recurrence was 24.3 months (SD 18.8) from the date of surgical excision. The two significant predictors of extra-pulmonary metastatic disease were: having >1 recurrent lesion (OR, 8.1; 95% confidence interval [CI] 1.9-33.6; p=0.004), and the presence of suspicious lymphadenopathy at the time of recurrence (OR, 14.1; 95% CI 3.3-61.0; p<0.001).

In patients with known recurrent lung cancer, the presence of >1 recurrent lesion and suspicious lymphadenopathy at recurrence were significant predictors of associated extra-pulmonary metastatic disease. These findings may help guide the risk stratification and management of patients with recurrent lung cancer.