Simultaneous renal clear cell carcinoma and gastrointestinal stromal tumor in one case.

Renal cell carcinoma is a tumor in kidney, while gastrointestinal stromal tumors are localized in the stomach and small intestine. They seldom occur simultaneously in sporadic case, both of which were suspective to sunitinib, a tyrosine kinases (RTKs) inhibitor. Our current case is novel in that concurrent RTK-related tumors are involved in one case. One possible explanation is the presence of some activating mutations.

INTRODUCTION

Renal cell carcinoma (RCC) is a common tumor in kidney, which accounts for 2-3% of all adult malignancies.[1] Gastrointestinal stromal tumors (GISTs) originate from the interstitial cells, which control gastrointestinal peristalsis. GISTs arise most commonly from the stomach.[2] The occurrence of them simultaneously remains an issue of great interest to surgeons and oncologists. Little is known about the genetic basis of any such associations. We present a case of concurrent a RCC and a GIST of stomach, both of which were suspective to sunitinib, a tyrosine kinases (RTKs) inhibitor.

CASE REPORT

A 65-year-old man presented to PeKing Union Medical College Hospital (PUMCH) with a four-month history of weakness, anorexia, upper abdominal discomfort, and weight loss of 3 kg. A 64-spiral computed tomography (CT) scanning of the abdomen demonstrated the presence of a 5 cm × 5 cm × 4 cm left renal mass and 10 cm × 9 cm × 8 cm gastric mass [Figures 1-3]. There were no metastases seen in the liver or lung. The patient underwent surgical resection with radical nephrectomy and partial gastrectomy. Histological appraisal of the specimens revealed a clear cell type Fuhrman grade 2 renal cell carcinoma and a gastrointestinal stromal tumor (GIST). All resection margins were clear of tumor and the GIST was positive for c-KIT and DOG-1. The patient was treated with sunitinib at a standard dose postoperatively (50 mg daily, 4 wk on, 2 wk off).

Figure 1

A 64-spiral computed tomography (CT) scanning of the abdomen demonstrated the presence of a 10 cm × 9 cm × 8 cm gastric mass

Figure 3

A 64-spiral CT scanning of the abdomen demonstrated the presence of a 5 cm × 5 cm × 4 cm left renal mass and 10 cm × 9 cm × 8 cm gastric mass

A 64-spiral CT scanning of the abdomen demonstrated the presence of a 5 cm × 5 cm × 4 cm left renal mass

DISCUSSION

The occurrence of two neoplasms in a single patient is an unusual occurrence.

The etiology of multiple primary tumors is quite complex, with genetic, environmental, hormonal, medical treatment-related, and gender-specific factors.[3] Both RCC and GIST may occur as recurrent familial tumors, related to mutations in the genes c-MET and c-KIT.[4] These are both RTKs. However, such germline mutations are rarely found in sporadic cases.

Clinically, sunitinib is effective against both tumors, which may represent a promising novel treatment approach for these patients. This agent potently inhibits the vascular endothelial growth factor receptor, platelet-derived growth factor receptor, and c-Kit in addition to other kinases proved in biochemical and cell-based assays.[5] It is now approved as first-line therapy for patients with RCC and second-line therapy for GIST by the US Food and Drug Administration in January 2006.[6-7]

Our current case is novel in that concurrent RTK-related tumors are involved in one case. In our case, first we used surgical resection with radical nephrectomy and partial gastrectomy. Surgical resection is the mainstay of treatment for patients with operable tumors. It was the only effective intervention prior to the novel targeted therapies, such as sunitinib. The case described is not only of interest due to the unusual co-incidence of two malignancies, but also emphasizes the importance of a thorough exploration of the patient. The role of this thorough search has clearly not been made obsolete by the tremendous advances in preoperative imaging modalities. The impact of synchronously existing tumors on the overall prognosis of a patient must be considered when planning therapy in such instances as well.