The Palouse Trial: Pathological Comparison Between in Vivo Lobectomy with Ex Vivo Segmentectomy for Clinically-Staged T1 And T2 Non-Small Cell Lung Carcinoma

Background: The standard curative treatment of early-stage NSCLC (non-small cell lung cancer) is a lobectomy with systematic lymph node dissection. A downside of lobectomy is the loss in lung parenchyma and due to mostly cardiopulmonary comorbidities, many patients with NSCLC are found medically unfit to undergo a lobectomy. For this reason, segmental resections of the lung have been gained increasing popularity in recent years for treatment of small tumours. However, the efficacy of sublobar resections for small tumours remains subject to debate. Non-randomized trials suggest a comparable survival but might be subjected to selection bias. No recent randomized clinical trials comparing these lobar and sublobar resections are available, which is due to lack of patient accrual and ethical issues. Till date, there is also no data on the pathological results of lobectomy and segmentectomy. Therefore, current guidelines continue to advise a lobar resection for the medically fit patients. The topic is becoming increasingly more relevant as more small-sized lung tumours are expected to be diagnosed in future through the aid of screening programs by the means of low-dose CT. The aim of this study is to assess if segmentectomy provides equal pathological complete resection compared with lobectomy in patients with clinically-staged T1 and T2 NSCLC. Materials and Methods: In this prospective multicentre cohort study*, adult patients with clinically-staged T1 or T2 N0 M0 NSCLC and found medically fit to undergo a lobectomy with systematic lymph node dissection, will be included. Patient will be treated with in vivo lobectomy. Afterwards, ex vivo segmentectomy will be performed. The resected segment will be examined for completeness of resection (R0- resection) and tumour margins. The remaining lobe will be meticulously examined for residual tumour, tumour satellites and cells. Individual patients will not benefit from participating in this study, nor will there be any burden as all patients will receive the standard curative lobectomy with lymph node dissection. *Collaborating hospitals: Department of Surgery of the Rijnstate Hospital, Slingeland Hospital, Canisius-Wilhelmina Hospital, Jeroen Bosch Hospital and the Department of Thoracic Surgery of the Isala Hospital. Results: The main endpoint is the percentage of R0 resections in the pathological report of ex vivo segmentectomies when compared with in vivo lobectomy. Other variables that are studied are demographic variables and perioperative variables. Moreover, number of lymph nodes and lymph node stations between segmentectomy and lobectomy will be compared. Results for T1 and T2 tumours will be compared. Conclusions: Segmentectomy might provide equal pathological complete resection compared with lobectomy in patients with clinically-staged T1 and T2 NSCLC. This study will compare ex vivo segmentectomy with standard in vivo lobectomy.