Circulating Tumor Cells (CTC) Before and After Thoracic Resection With and Without Intraoperative Use of ExtraCorporeal Membrane Oxygenator(ECMO) or Cardio Pulmonary By Pass (CPB)

Overview

The role of circulating tumor cells (CTC) in patients suffering from lung cancer and thoracic malignancies is not well known and it is still widely debated. The use of intraoperative cardiorespiratory supports like ECMO (extracorporeal membrane oxygenator) and CPB (cardiopulmonary by-pass) during extended resections in oncologic patients has been questioned because of the theoretical risk of tumor cells spreading, although there is no clinical or experimental evidence supporting this hypothesis. The aim of the present study is to quantify the possible presence and amount of CTC in the peripheral blood of patients undergoing lung/mediastinal resection, before and after surgical procedure, comparing patients receiving intraoperative cardiorespiratory support with patients - with similar oncologic disease and extension - operated without the need of ECMO or CPB.

Background and Rationale: Locally advanced pulmonary and mediastinal cancers invading vital structure such as heart, great vessels, or carina cancer are generally considered as unresectable and incurable. Complete resection in healthy tissue may be compromised due to the proximity of the tumors to vital organs \[1, 2\]. Palliation with chemotherapy and/or radiotherapy is the principal means of treatment \[1, 2\]. In highly selected patients with specific anatomic conditions, complete R0 resection for locally advanced tumor has been reported with prolonged survival and, on occasion, resulted in cure \[3-5\]. Complex cardiac resections or reconstructions, replacement of the thoracic aorta, or the common pulmonary artery can only be approached with cardiac arrest and total circulatory support by standard cardio-pulmonary bypass (CPB) \[6,7\]; extracorporeal membrane oxygenation (ECMO) is a well- established technique for the management of respiratory or hemodynamic disturbance during lung transplantation. Technological advances in pumps, cannulae, and oxygenators and growing experience for thoracic surgeon during lung transplantation have led to the use of ECMO during conventional thoracic surgical procedure \[8,9\]. A theoretical possibility of enhancement of metastasis due to ECMO or CPB has been reported \[10\] although no clear evidence exists ; nevertheless, due to the lack of data about this aspect, many cardio-thoracic surgeons are skeptical about the use of intraoperative CPB or ECMO . The aim of this protocol is to assess the presence or not and possibly the amount of CTC before and after surgery in the peripheral blood of patients undergoing thoracic resection with (experimental arm) or without (control arm) intraoperative support of ECMO or CPB. Study design and duration Prospective, double arm , observational study. Ten consecutive patients - with thoracic malignancies undergoing resection with planned intraoperative cardiorespiratory support - will be enrolled. Before surgery peripheral blood samples will be collected (as subsequently described) to search the presence and the amount of CTC. The patients will then undergo surgical procedure with intraoperative ECMO or CPB support. After the procedure peripheral blood samples will be collected as previously reported to search for CTC. Ten consecutive patients, presenting the same neoplastic diseases of the experimental arm and with same extension but not requiring intraoperative ECMO or CPB support will be enrolled in the control arm, receiving the same blood sample collection before and after surgery, to assess the presence and the amount of CTC. The two groups will be than compared in terms of preoperative and postoperative CTC presence and amount.