It is estimated that there are approximately 295,000 new cases of RCC worldwide, with only 134,000 patients able to be diagnosed [5-7]. The ratio of male to female is close to 2:1 . The average age of patients diagnosed is 64 years . The incidence of kidney cancer is increasing every year along with the increase in obesity rate . A third of new kidney cancer patients already have distant metastases, and another third still develop subsequent multiple metastases that are untreatable after RCC resection. In fact, the 5-year survival rate for patients with renal carcinoma is only 13% due to multiple metastases and underlying disease . Clinical data show that patients with delayed metastases have a better prognosis than patients with concurrent metastases in renal carcinoma. The median survival time of patients with untreated advanced kidney cancer is 4 months, while the one-year survival rate is only 10% ; therefore, primary and metastatic lesions should be treated as much as possible [13, 14]. Clinical data from Talarico and Skinner showed a median survival was 33 months for patients with metastases within 1 year of kidney cancer resection; and 55 months for patients with metastases after 1 year [15, 16]. Kozlowski et al. reported that only 2-4% of patients with liver metastases from kidney cancer had access to surgery . In 1939, Barney first reported lung metastasis occurred in patients with renal cancer after resecting primary lesion by surgical treatment for 23 years .
According to the data reported in various articles, although surgical resection is the basic treatment for liver metastasis of renal carcinoma, the therapeutic effect has not been fully affirmed. This uncertainty is mainly due to the small number of reported cases and a large number of variables. The 3-and 5-year survival rates of patients with single metastatic tumor after surgical resection were 45% and 34%, respectively . The perioperative mortality rate in each center ranged from 3 to 31%, depending on the number of metastases and the surgical approach.
With the development of targeted therapy in recent years, RCC treatment has become one of the most successful cases in cancer research. These drugs include VGFR and MTOR, as well as new immuno-oncology drugs . Patients with metastatic RCC have spontaneously resolved metastases after surgical removal of the primary tumor, suggesting that RCC may be a good immunotherapy disease [21, 22]. Cytokines, interleukin-2 and interferon can effectively treat some patients. These new immunotherapies are becoming more and more important in the treatment of renal carcinoma. Although these methods are still in clinical trials, their successful applications in other types of cancer suggests that they may ultimately be beneficial for renal carcinoma patients. Immunotherapy, particularly immune monitoring site inhibitors such as PD1 antibodies and anti-PDL1 antibodies, has shown promising results in the treatment of renal carcinoma [23-25]. The therapeutic efficacy of metastatic renal carcinoma has been improved significantly in the past decade or so due to the emergence of new tumor therapies. Although various treatments are still in the experimental stage, the results are inspiring. Surgical resection combined with immunotherapy significantly increased survival in patients with metastatic renal cancer.
In this article, we first report the application of laparoscopic techniques in the surgical treatment of patients with single liver metastases of RCC. Interferon and PD1 antibody were given after operation. At present, no obvious recurrence or metastasis was observed during the 6-month follow-up. With the development of endoscopic technology, more treatment options will be available for patients with less trauma and faster recovery. Due to the small number of cases and lack of more clinical observation data, its long-term effects need further observation.