Background To assess long‐term oncologic outcomes of robotic‐assisted liver resection (RLR) for colorectal cancer (CRC) metastases as compared to a propensity‐matched cohort of laparoscopic liver resections (LLR). Although safety and short‐term outcomes of RLR have been described and previously compared to LLR, long‐term and oncologic data are lacking. Methods A retrospective study was performed of all patients who underwent RLR and LLR for CRC metastases at six high‐volume centers in the USA and Europe between 2002 and 2017. Propensity matching was used to match baseline characteristics between the two groups. Data were analyzed with a focus on postoperative and oncologic outcomes, as well as long‐term recurrence and survival. Results RLR was performed in 115 patients, and 514 patients underwent LLR. Following propensity matching 115 patients in each cohort were compared. Perioperative outcomes including mortality, morbidity, reoperation, readmission, intensive care requirement, length‐of‐stay and margin status were not statistically different. Both prematching and postmatching analyses demonstrated similar overall survival (OS) and disease‐free survival (DFS) between RLR and LLR at 5 years (61 vs. 60% OS, p = 0.87, and 38 vs. 31% DFS, p = 0.25, prematching; 61 vs. 60% OS, p = 0.78, and 38 vs. 44% DFS, p = 0.62, postmatching). Conclusions Propensity score matching with a large, multicenter database demonstrates that RLR for colorectal metastases is feasible and safe, with perioperative and long‐term oncologic outcomes and survival that are largely comparable to LLR.

BackgroundThe development of immunotherapy has led to significant progress in the treatment of metastatic cancer, including the development of genetic engineering technologies that redirect lymphocytes to recognize and target a wide variety of tumor antigens. Chimeric antigen receptors (CARs) are hybrid proteins combining antibody recognition domains linked to T cell signaling elements. Clinical trials of CAR-transduced peripheral blood lymphocytes (PBL) have induced remission of both solid organ and hematologic malignancies. Chondroitin sulfate proteoglycan 4 (CSPG4) is a promising target antigen that is overexpressed in multiple cancer histologies including melanoma, triple-negative breast cancer, glioblastoma, mesothelioma and sarcoma.MethodsCSPG4 expression in cancer cell lines was assayed using flow cytometry (FACS) and reverse-transcription PCR (RT-PCR). Immunohistochemistry was utilized to assay resected melanomas and normal human tissues (n = 30) for CSPG4 expression and a reverse-phase protein array comprising 94 normal tissue samples was also interrogated for CSPG4 expression. CARs were successfully constructed from multiple murine antibodies (225.28S, TP41.2, 149.53) using second generation (CD28.CD3ζ) signaling domains. CAR sequences were cloned into a gamma-retroviral vector with subsequent successful production of retroviral supernatant and PBL transduction. CAR efficacy was assayed by cytokine release and cytolysis following coculture with target cell lines. Additionally, glioblastoma stem cells were generated from resected human tumors, and CSPG4 expression was determined by RT-PCR and FACS.ResultsImmunohistochemistry demonstrated prominent CSPG4 expression in melanoma tumors, but failed to demonstrate expression in any of the 30 normal human tissues studied. Two of 94 normal tissue protein lysates were positive by protein array. CAR constructs demonstrated cytokine secretion and cytolytic function after co-culture with tumor cell lines from multiple different histologies, including melanoma, breast cancer, mesothelioma, glioblastoma and osteosarcoma. Furthermore, we report for the first time that CSPG4 is expressed on glioblastoma cancer stem cells (GSC) and demonstrate that anti-CSPG4 CAR-transduced T cells recognize and kill these GSC.ConclusionsThe functionality of multiple different CARs, with the widespread expression of CSPG4 on multiple malignancies, suggests that CSPG4 may be an attractive candidate tumor antigen for CAR-based immunotherapies using appropriate technology to limit possible off-tumor toxicity.

RLS can be performed for primary hepatobiliary malignancies with long-term oncologic outcomes comparable to published open and laparoscopic data.