Mortality from post-transplant malignancy is increasing among recipients of solid organs.(12, 13) Transplant recipients are at a higher risk of cancer, compared to the rest of the population. The incidence of malignancies in liver transplant recipients is reported to range from 3–16%. The management of post-transplant malignancy is challenging.(14)
The increased risk of post-transplant malignancy is attributed to two sets of factors. The first set of risk factors is the presence due to prolonged immunosuppression, which may result in infection or reactivation of oncogenic viruses. There is also impaired immune surveillance that may inhibit the response of the body’s immune system to the presence of malignant cells in the system. The impaired immune surveillance is due to the inhibition of T lymphocytes, macrophages, and natural killer cells. These immune cells are responsible for delays in tumor progression, inhibition of angiogenesis, vascular invasion, and metastasis.(15, 16) The second set of factors associated with increased risk of malignancy after liver transplantation is already present at the time of transplantation. Such factors include the underlying cause of the liver disease (primary sclerosing cholangitis or alcoholic liver disease), tobacco use, coexisting premalignant conditions at the time of transplantation, or history of pre-transplant malignancy. Infections with Helicobacter pylori and Epstein Barr Virus after liver transplantation have been associated with post-transplant gastric cancer.(15, 16)
The most common malignancies seen in adult recipients of liver transplants are post-transplant skin cancers, colorectal malignancies, and lung cancers.(7) The incidence of post-transplant gastric cancer is low in Europe and North America. However, reports from East Asia showed that gastric cancer is common after liver transplantation. Studies by Cong et al. and Lee et al. showed that the incidence of post-liver transplant gastric cancer is higher than those reported in Europe and the Americas.(8, 17)
The mainstay of treatment of gastric cancer in recipients of liver transplantation is gastrectomy with D2 dissection.(9–11) One of the challenges one should anticipate include dense abdominal adhesions from previous liver transplant surgery, and this is why most of the reports of gastrectomy for gastric cancer in liver transplant recipients have been open gastrectomy, like in our patients.(10) However, there are case reports of successful laparoscopy-assisted distal gastrectomy for gastric cancer after liver transplantation.(18) Endoscopic submucosal dissection should be considered in patients with early gastric cancer with no lymph node involvement. Another challenge for gastrectomy in recipients of liver transplants is the alteration of lymphatic flow due to previous hilar dissection during liver transplantation. Despite this alteration in flow, D2 dissection should still be performed in these patients with careful lymph node dissection, especially in stations 5, 8a, and 12a which are close to the reconstructed hepatic inflow vessels and bile ducts.(10)
The next challenge is the management of immunosuppressive medication during the perioperative period. The current recommendation is to continue the immunosuppressive medications up to the day of surgery. The medication should also be commenced through a nasogastric tube at postoperative day one.(10) This should be maintained at an appropriate trough level of immunosuppression to prevent rejection during the perioperative period. During the immediate postoperative period, there is a need to closely monitor the liver function test and the level of immunosuppressive drugs.(10)