Serial Pancreas, Liver and Duodenal Metastasis from Renal Clear Cell Cancer: a Case Report

Discussion

Renal clear cell cancer is the most common histological renal cell carcinoma subtype. It can metastasize to the lung, bone, brain and liver via the blood and lymph system, as well as infrequently to other organs of the body such as the testis, pineal gland, tongue, ovary, thyroid gland, nose and paranasal sinuses, etc^[1-6]. In this patient with primary renal clear cell cancer, serial pancreatic, liver and duodenal metastasis occurred within 3 years.

It is known that renal clear cell cancer is responsive to immunotherapeutic approaches such as interleukin 2 (IL-2) or IL-2 plus lymphokine-activated killer (LAK) cells, and immune-mediated mechanisms play important roles in limiting tumor growth^[7,8]. Therefore, to preserve the remnant renal function in this aged patient with only a left kidney due to a previous cancerous right nephrectomy, bio-immunotherapy was adopted. In addition, photodynamic therapy (PDT), an effective minimally invasive means, was also applied. This therapeutic approach is currently being used in the treatment of many cancers including the lung, head and neck cancers, liver metastases and cholangiocarcinoma. It also has been employed for prostate cancer through enhancement of cell apoptosis, microvascular damage and an antitumor immune response^[9]. In this patient, the significant regression of the left renal remnant carcinoma lesion indicated by follow-up abdominal CT scans every 3 months demonstrated the efficacy of PDT and bio-immunotherapy.

However, secondary widespread pancreatic metastasis occurred within 16 months despite inhibition of the primary renal cancer lesion, and unfortunately, the poor state of this aged patient excluded the feasibility of pancreaticoduodenectomy and pancreatic transplantation. Therefore, an intra-bile stent of the common bile duct was implanted to avoid its occlusion from growth of the pancreatic tumor head. At the same time, three-dimensional conformal radiotherapy combined with high intensive focused ultrasound directed to the neoplasm in both the head and body of pancreas, was conducted as a palliative anti-cancer treatment and to alleviate abdominal pain. Guided by real-time ultrasonographic (US) imaging, high intensity focused ultrasound brings thermal and cavitation effects of ultrasound energy deposited in the target tumor, which in turn induces coagulation-tumor necrosis^[10]. To reduce the risk of complications, an endobiliary stent should be routinely placed before high-intensity focused ultrasound in patients with cancers in the pancreatic head^[11]. No severe side effects such as tumor hemorrhage, large blood vessel rupture, peritonitis, obstructive jaundice, or gastrointestinal perforation in this patient were observed during the follow-up period.

For those patients with an unresectable advanced pancreatic cancer, three-dimensional conformal radiotherapy also provides a feasible approach to inhibit tumor growth^[12]. As a high dose targeted at the tumor can be given in a fraction, and the normal surrounding tissues are only exposed to low-dose radiation, a good therapeutic effect with minimized adverse effects on normal tissues in relation to the exposure can be achieved. In addition, subcutaneous administration of somatostatin had some inhibitory effect on the growth of both the primary and secondary pancreatic tumor.

Unfortunately, the overall status of this patient deteriorated gradually and liver metastasis from the renal clear cell cancer occurred one and a half years after pancreatic metastasis. The character of the liver metastatic lesion could be defined by spine-biospy of the lesion, but this diagnostic method might have led to transfixion-mediated tumor metastasis, and was of little use for determination of the treatment. Secondary liver metastasis was then diagnosed by integral analysis of the disease history, laboratory findings and abdominal CT imaging. Although surgical resection remains as a curative treatment for hepatic metastastic cancer, transcatheter arterial chemoembolization (TACE) has become an effective option for those unresectable liver metastases from pancreatic carcinoid tumor, gastric, colorectal, or breast cancers^[13-16]. In view of the rich blood supply of liver metastatic carcinomas as well as the poor condition in this aged patient, a selective TACE was performed to prolong survival. As to the management of the pero-intestinal obstruction caused by the duodenal metastasis, total parenteral nutrition was adopted.

In summary, from both diagnosis and treatment of this patient, it can be concluded that it was important to perform a comprehensive analysis of the patient’s total status along with condition of the tumor, in order to obtain a rational therapeutic regimen.