Prognostic significance of mediastinal standardized uptake value on positron emission tomography/computed tomography in patients with left upper lobe non-small cell lung cancer: Is invasive staging of aortopulmonary window lymph nodes necessary?

Abstract

Background: This study aims to investigate whether the invasive staging of aortopulmonary window lymph nodes could be omitted in the presence of a suspected isolated metastasis in the aortopulmonary window lymph node on positron emission tomography/computed tomography. Methods: Between January 2010 and January 2016, a total of 67 patients (54 males, 13 females; mean age: 59.9±8.7 years; range, 44 to 76 years) with metastatic left upper lobe tumors to aortopulmonary window lymph nodes were retrospectively analyzed. According to positron emission tomography/computed tomography findings in clinical staging, the patients were classified as positive (+) (n=33) and negative (-) (n=34) groups. Results: There was a statistically significant difference between the two groups in terms of sex distribution, lymph node diameter on computed tomography, maximum standardized uptake value of aortopulmonary window lymph nodes, and tumor diameter (p<0.001 for all). A trend toward significance was found to be in pT status, LN #6 metastases, and pathological stage between the two groups (p=0.067). The five-year overall survival rate for all patients was 42.4% and there was no significant difference between the groups (p=0.896). The maximum standardized uptake value of the aortopulmonary window lymph nodes was a poor prognostic factor for survival (area under the curve=0.533, 95% confidence interval: 0.407-0.675, p=0.648). Conclusion: Invasive staging of aortopulmonary window lymph nodes can be omitted in patients with isolated suspected metastasis to aortopulmonary window lymph nodes in non-small cell lung cancer of the left upper lobe.