Repeat mediastinoscopy in all its indications: experience with 96 patients and 101 procedures

To evaluate the accuracy of repeat mediastinoscopy (reMS) in all its indications, and to analyse survival in the group of patients who underwent induction chemotherapy or chemoradiotherapy for pathologically proven stage III-N2 non-small-cell lung cancer (NSCLC).

From July 1992 to February 2009, 96 patients (87 men; median age: 61.3 years), underwent 101 reMSs (five patients required a second reMS) for the following indications: restaging after induction therapy for pathologically proven N2 disease (84 cases), inadequate first mediastinoscopy (five), metachronous second primary (six) and recurrent lung cancer (six). Patients with N2-NSCLC, who had received induction therapy and had positive reMS, underwent definitive chemotherapy or chemoradiotherapy. Patients in whom reMS was negative underwent thoracotomy for lung resection and systematic nodal dissection (SND). SND was considered the gold standard to compare the negative results of reMS. Pathologic findings were reviewed and staging values were calculated using the standard formulas. Follow-up data were completed in January 2010, and survival analysis was performed by the Kaplan-Meier method.

In the group of reMS for restaging after induction therapy, the staging values were: sensitivity 0.74, specificity 1, positive predictive value 1, negative predictive value 0.79 and diagnostic accuracy 0.87. We also determined the diagnostic value of this technique according to the type of induction treatment. In terms of accuracy, no statistically significant differences were found. Median survival time in patients with true negative reMS was 51.5 months (95% confidence interval (CI) 0-112), and in the combined group of patients with positive and false-negative reMS, median survival time was 11 months (95% CI 7.6-14.1) (p=0.0001). In the group of miscellaneous indications, all staging values were 1.

ReMS is feasible in all the indications described. After induction therapy, it is a useful procedure to select patients for lung resection with high accuracy, independently of the induction treatment used or the intensity of the first mediastinoscopy. The persistence of lymph node involvement after induction therapy has a poor prognosis. Therefore, techniques providing cytohistological evidence of nodal downstaging are advisable to avoid unnecessary thoracotomies.