Dissertation Morten Hagness - Transplantation surgery
Morten Hagness at the Institute of Clinical Medicine and the Biotechnology Centre of Oslo will defend his thesis for the Ph.D. grade (philosophiae doctor): Liver Transplantation for Colorectal Liver Metastases - Clinical and Immunological Considerations.
Transplant surgeon and researcher Morten Hagness has studied liver transplantation as a treatment against liver metastases in colorectal cancer patients. Colorectal cancer is a common type of cancer and often spreads to the liver. If the liver metastases are not surgically removed, the patients have poor prognosis. In the SECA study, liver transplants were performed as treatment in patients with this condition. Of the 21 patients that participated in the study, 6 out of 10 were still alive after 5 years and 7 patients were cancer free. Without the liver transplant less than 1 out of 10 would most likely still be alive after 5 years. This study is unique internationally.
Donor livers are a limited resource and it is therefore very important that new indications for liver transplantations have good long-term results. In the SECA material factors were found that will enable us to identify the patients that will benefit most from a liver transplant. This will improve the long-term outcomes further. Many of the patients had recurrence of cancer after transplantation. Secondary cancer in the lung appeared to grow slowly and could often be surgically removed. Furthermore, it also turned out that some of the patients had lung metastases already at the time of transplantation without this affecting survival negatively. Recurrence in the new liver did only occur when cancer spread to several organs and this was a poor prognostic sign.
Liver transplant patients must be on lifelong immunosuppressive therapy to prevent rejection of the donor liver. This is a double-edged sword since the immune system is important to fight cancer cells. Regulatory T cells inhibit other immune cells and it is potentially beneficial to be able to control them both in regard to transplantation as well as in cancer treatment. However, the inhibitory mechanisms are not known. Hagness and his colleagues have studied how regulatory T cells become inhibitory and how these cells respond to immunosuppressive therapy. A new finding is that half of the healthy population have activated regulatory T cells.