Role of Surveillance Imaging Versus Symptoms and Signs in Detection of Recurrence of Non-Small Cell Lung Cancer After Curative Intent Therapy

Abstract

Lung cancer is the most common cause of cancer-related mortality in the United States. While studies suggest that symptoms and physical exam signs detect recurrence as well as imaging for Non-Hodgkin’s Lymphoma, few studies have examined this issue in Non-Small Cell Lung Cancer (NSCLC). We compared surveillance imaging with symptoms and signs as modalities of recurrence detection in NSCLC. The goal of this study was to determine what proportion of recurrences was found by surveillance imaging versus by symptoms/signs and to compare survival outcomes between imaging- and symptom/sign-detected recurrences. We retrospectively reviewed records of patients who underwent curative intent therapy and surveillance imaging at our institution for Stage I-III NSCLC diagnosed between 2004 and 2013. Exclusion criteria included NSCLC metastasis during treatment, synchronous primaries, second primary after treatment, other metastatic malignancies, and discontinuation of follow-up after treatment. Locoregional recurrence (LR) comprised failure within ipsilateral lung and/or new hilar or mediastinal lymphadenopathies. Distant recurrence (DR) comprised metastases to contralateral lung and/or extrathoracic sites with or without LR. Chi square test and Cox regression were used to compare the association of imaging or symptoms/signs with type of recurrence and survival outcomes. Out of 1197 patients treated for NSCLC between 2004 and 2013 at our institution, 508 met the inclusion criteria for analysis. Of that cohort, we identified 203 patients who developed recurrence a median of 11.5 months after completion of treatment, 42.4% with initial stage I disease; 13.8% with Stage II; and 43.8% with stage III. LR was found in 88 (43.3%) patients and DR in 115 (56.7%). Patients with LR and DR had a median survival (95% CI) from the time of recurrence of 2.01 (1.48-2.54) and 0.88 years (0.71-1.06), respectively (log-rank: P = 0.0003). Surveillance imaging detected 71.9% of all recurrences, symptoms detected 26.6%, and physical exam signs detected 1.5%. Compared with symptoms/signs, surveillance imaging detected 96.6% of LR and 53.0% of DR (Chi square test: P < 0.0001). In univariate Cox regression, symptom/sign-detected recurrences were associated with decreased overall survival (OS) compared with imaging-detected recurrences (Hazard Ratio [HR] = 1.79, 95% CI = 1.25-2.58, P = 0.002). In patients with LR, initial stage was not associated with differences in OS on univariate and multivariate Cox regression. The ability of imaging to detect most LR, which are candidates for potentially curative salvage therapy, suggests a potential benefit of post-treatment surveillance imaging in patients with Stage I-III NSCLC.