Inflammation and Tumor Progression in Patients after ALPPS Procedure: Two Sides of the Same Story?

Introduction: Despite the great virtues of the new Future Liver Remnant (FLR) hypertrophic techniques developed in recent years for the surgical management of Colorectal Cancer (CRC) liver metastases, the effect of these on tumor progression has been questioned in experimental studies. These have shown a change in the inflammatory response after surgery, conditioned by a switch in the phenotype of macrophages. This correlates with greater replication and tumor de-differentiation. The aim of this study is to analyze the type of inflammatory response and the role of macrophages in the tumor microenvironment in patients with hepatic metastases of CRC undergoing ALPPs from 2011 to 2015. Methods: The study included 11 patients operated for hepatic CRC metastases using the ALPPS technique. Samples of metastases were taken in the first and second surgical stages. An immunohistochemical study was carried out for expression of Ki67 from tumor cells of the M1 and pressence of M2 macrophages by means of the immunomarker CD163. Results: Similar to the results reported in experimental studies, a significant increase in Ki67 was observed in liver tumoral M1 cells, comparing the first and second surgical time. Likewise, the expression of CD163 in the second surgical time showed a significant increase. Conclusion: The ALPPS technique may induce a phenotypic change in the inflammatory response that could condition an increase in tumor proliferation and cellular dedifferentiation.