Discordance between clinical and post-surgical staging of patients with operable non-small cell lung cancer: a retrospective audit of lung cancer surgery with curative intent from a single pathology practice

Clinical staging of non-small cell lung cancer (NSCLC) by CT and PET, with or without endobronchial ultrasound-guided transbronchial needle aspiration of lymph nodes (EBUS-TBNA), is essential for prognostication and to direct treatment. Clinical understaging can lead to inappropriate radical excision of the primary tumour with no clinical benefit, whereas overstaging might deprive patients of beneficial or potentially curable treatments. Although not widely documented, several reports have indicated a suboptimal concordance between clinical and post-surgical staging. This study has investigated the incidence of discordance between clinical and post-surgical staging of operable NSCLC cases evaluated at PathWest Fiona Stanley Hospital (Perth, WA, Australia).The study formed part of an approved Quality Improvement Activity and included patients with NSCLC who underwent lobectomy between Jan 1, 2016, and Dec 31, 2021, at hospitals serviced by the PathWest anatomical pathology department at Fiona Stanley Hospital. Data from pathology, imaging, and EBUS-TBNA or biopsy reports were retrieved from digital medical records databases and multidisciplinary meeting notes. A project database designed and established in REDCap was used to collect and analyse data.419 patients (216 [52%] women, 203 [48%] men) in the age range of 20·5-85·8 years (median 69·2 years [IQR 63·3-74·5]) were included. EBUS-TBNA was done for 121 (29%) patients and imaging results (from CT, PET, or both) were available for 406 (97%) patients. Discordant clinical and post-surgical T and N staging were evident; post-surgical T stage was higher in 96 (23%) cases and lower in 54 (13%) cases. Eight tumours staged post-surgically as N1 had been clinically staged as N0. For ten cases with unforeseen N2 involvement, clinical staging was N0 (n=4), N1 (n=3) or not available (n=3); surgery might not have been necessary for these patients. Median times between CT and lobectomy (105 days [IQR 77·0-143·0]), PET and lobectomy (79 days [56·0-109·0]), and EBUS-TBNA and surgery (59 days [42-94]) were outside of Australian guidelines, which recommend a time to start of treatment for lung cancer of less than 42 days from initial referral. Time intervals between final screening study (imaging or EBUS-TBNA) and lobectomy before and during the COVID-19 pandemic (2016-19 and 2020-21, respectively) were significantly different (p=0·019). It is noteworthy that Western Australia had not recorded high numbers of COVID-19 cases during that time.This study has identified substantial disagreement between clinical and post-surgical staging of NSCLC. Discordance between clinical and post-surgical T and N staging might have led to different treatment pathways for some patients. To improve the accuracy of clinical staging of NSCLC, the sensitivity, specificity, and interpretation of imaging and lymph node cytology, as well as the timeliness of treatment (clinical care pathway) would each need to be evaluated. Strengths of this study include the large number and lack of selection of cases, and the small number of medical service providers. Weaknesses include the absence of outcomes data for these patients. Overall results are consistent with previous and historical investigations of hospital and clinical trial cohorts.OT is the recipient of a student scholarship from the Royal College of Pathologists of Australasia that funded this work.