Endosonography for lung cancer staging: predictors for false-negative outcomes

Three predictors for false-negative outcomes were identified: central location of the lung tumor (OR 3.7/4.5/3.6 for EBUS, EUS and EUS/EBUS respectively, p < 0.05), nodal enlargement on CT (OR 3.2/2.5/4.9 for EBUS, EUS and EUS/EBUS respectively, p < 0.05) and FDG-avidity of N2/N3 lymph node stations on PET (OR 4.2/4.0/7.5 for EBUS, EUS and EUS/EBUS respectively, p < 0.05). One subgroup (peripheral lung tumor, nodal enlargement on CT without FDG-avidity for N2/N3) had a low predicted probability (7.8%) for false-negative EUS. For combined EUS/EBUS, two subgroups were identified: peripheral located tumor with nodal enlargement on CT but without FDG-avidity for N2/N3 (predicted probability 4.7%) and centrally located tumor without affected lymph nodes on CT or PET (predicted probability 3.4%). In conclusion, for specific well-defined subsets of NSCLC patients the low predicted probability of metastasis after negative endosonography might justify omitting confirmatory surgical staging.