Complete and accurate staging for patients diagnosed with lung cancer to assess the extent of disease is of critical importance so that appropriate treatment recommendations

J Thorac Dis 2019;11(Suppl 9):S1322-S1324 | http://dx.doi. org/10.21037/jtd.2019. 04.18 Complete and accurate staging for patients diagnosed with lung cancer to assess the extent of disease is of critical importance so that appropriate treatment recommendations may be provided (1). An incorrect clinical staging classification can lead to wrong decisions on withholding potentially curative resection as well as inappropriate nonsurgical definitive therapy and palliative treatment options. In their study, Navani and colleagues analyzed the accuracy of clinical staging for stage I–IIIa non-small cell lung cancer (NSCLC) (2). Navani and coworkers employed individual participant data from a meta-analysis of randomized, controlled trials comparing preoperative chemotherapy (± radiotherapy) to surgery alone in NSCLC (2). They evaluated the concordance between the clinical TNM (cTNM) stage at randomization and pathologic TNM (pTNM) stage following surgery for patients in the surgery only group (control group). Nine studies were included in the analysis with the study accrual periods ranging from 1987 to 2005. There was a low amount of agreement between cTNM and pTNM staging at 52% (weighted Cohen’s κ =0.35). Clinical understaging occurred in 34% of cases and in clinical overstaging occurred in 14% of cases. Clinical staging failed to detect nodal involvement in 19% of cases while 12% of patients were erroneously concluded to have nodepositive disease. Survival varied with the accuracy of cTNM staging. A worse survival was noted in clinically understaged patients as compared to patients that were correctly staged or clinically overstaged. However, this result was driven by the underlying pTNM stage; 44% of patients classified as cTNM stage I were found on pathologic staging to be stage II–IV, and 33% of patients classified as cTNM stage II were found on pathologic staging to be stage III–IV, thus accounting for their lower survival. While the study by Navani and colleagues was well done, the results are not surprising and do not provide additional information to the understanding of the current performance of NSCLC staging methodologies. Of the 9 included studies in their analysis, one study used chest radiography (3), one study used chest computed tomography (CT) and positron emission tomography (PET) imaging (4), and 2 studies used chest CT plus abdominal ultrasound (5,6) while the other studies used chest CT alone as the imaging modalities for staging (7-11). In the study that did use PET imaging, PET scanning was not routinely used during the study period and only 67 of the 261 patients underwent PET scan as a part of their staging (2). Navani and coworkers note that two of the included trials in the analysis used mediastinoscopy as part of the staging protocol. In the study by Gilligan and colleagues, however, the authors note that most patients were staged by bronchoscopy and chest CT since mediastinoscopy and PET scan were not standard practice in the United Kingdom at the time of the trials’ inception (4). The study by Splinter and coworkers is reported in abstract form so it is unknown how systematically mediastinoscopy was performed (8). In the studies by Gilligan (4), Wu (5), and Yang (6), bronchoscopy was used as part of the staging process however the type of bronchoscopic staging was not specified in these studies and all of these studies predated Editorial Commentary