Metastatic gastric tumors arising from renal cell carcinoma: Clinical characteristics and outcomes of this uncommon disease

We analyzed the clinicopathological characteristics and therapeutic outcomes of patients with metastatic gastric tumors arising from renal cell carcinoma (RCC) to identify post-therapy prognostic factors. A total of 22 patients who were treated for metastatic gastric tumors arising from RCC were included in the study. A retrospective review was performed on the clinical characteristics of this disease. The median time interval from radical excision of the primary tumor to the detection of gastric metastasis (IGM) was 6.3 years. The overall 1- and 3-year survival rates were 52.6 and 21.0%, respectively, and the median survival time was 19 months. Compared with patients with an IGM of <6.3 years, patients with an IGM of >= 6.3 years showed a significantly longer median survival time (5 vs. 24 months; P=0.017). The median tumor size was significantly greater in patients with multiple metastases compared with those with solitary metastasis (4 vs. 2 cm; P=0.036). The incidence of patients who had undergone therapeutic tumor resection was significantly higher in patients with solitary metastasis compared with those with multiple metastases (100.0 vs. 35.7%; P=0.019). The appearance of gastric tumors in patients with a history of RCC should prompt the clinician to investigate the possibility of metastasis even several years after detection of the original renal cancer. A longer interval from nephrectomy to the diagnosis of gastric metastasis is generally indicative of a better prognosis, most likely the result of less aggressive tumor growth.