Gastric or duodenal metastases from clear cell renal cell carcinoma. Report of two cases and review of the literature

Introduction : Gastric or duodenal metastases from clear cell renal cell carcinoma are exceptional. According to autopsy series, the incidence of gastrointestinal metastases is 0.06 to 4% for all cancers and 0.2 and 0.7% for renal cancers. Objective : To define the diagnostic and therapeutic management of these rare sites in the light of 2 cases of gastric metastases from renal cancer seen in our institution and a review of the literature. Results : These two patients with gastric or duodenal metastases from renal cancer can be added to the 15 cases found in the literature. These 17 cases consisted of 5 cases of duodenal metastases and 12 cases of gastric metastases and were described in 14 articles (2 articles comprised 2 and 3 cases, respectively). Metastases were the presenting sign of the cancer in 3 cases or occurred during follow-up after nephrectomy in 14 cases after a mean of 6.6 years (range: 2 years-14 years). The mean number of metastatic sites was 2.5 (range: 1-5). Presenting symptoms were mainly upper or lower gastrointestinal bleeding (14 out of 17 cases) or anaemia (2 cases). Gastroscopy established the diagnosis and allowed biopsies and control of acute bleeding. For patients with a solitary metastasis and in good general condition, gastrectomy was performed as complementary treatment. For patients with multiple or inoperable metastases, treatment consisted of either endoscopic resection, embolization of the metastasis, or immunotherapy. The benefit of surgery in terms of survival could not be demonstrated due to the short follow-up (mean: 8.6 months; range: 1 to 36 months). The median overall survival of this group has not been reached, but is greater than 6 months. Conclusion : Surgical resection of the metastasis is the preferred treatment in the case of a solitary metastasis and absence of contraindication related to the general state. In the other cases, endoscopic resection or embolization of the metastasis can be proposed, with or without systemic immunotherapy. None of these treatments has been shown to be superior in terms of survival in this indication. The place of targeted anti-tumour treatments such as anti-angiogenic drugs has not been evaluated.