Background: Solitary metastases from a primary renal cell carcinoma (RCC) occur in < 10% of patients with metastatic RCC. To date, the benefit of surgically resecting such apparently solitary lesions has not been well documented.
Materials and methods: Forty-one patients (25 men, 16 women) with metastatic renal cell carcinoma treated by surgical excision of solitary metastases (1970-1990) were retrospectively reviewed. They comprised 9% of patients with metastatic hypernephroma seen during this period. All patients had undergone previous curative nephrectomy with a median disease-free interval of 27 months. Patients with skeletal, spinal cord, and lymph node metastases were excluded.
Results: Metastases were intrathoracic (n = 20), intracranial (n = 7), and intraabdominal or in the extrapleural chest wall soft tissue (n = 10). Three patients had metastases to the thyroid gland and one had a solitary metastasis to an index finger. Median follow-up was 3.2 years. Complete resection was possible in 36 patients (88%) with a single lesion excised in 23 of these 36 patients (64%). There was no operative mortality. Predicted survival from the date of complete resection of metastases was 77%, 59%, and 31% at 1, 3, and 5 years, respectively, with a median survival of 3.4 years. One patient is alive without evidence of recurrent tumor 93 months from the first of 12 complete surgical resections. Varying adjuvant therapy was used in 50% of the patients. An increased histological tumor grade of the metastatic lesion relative to the original RCC was the only significant prognostic indicator identified. Disease-free interval and number of resected lesions were not significantly associated with patient survival.
Conclusion: A small fraction of renal cell carcinoma patients are candidates for potentially curative surgical resection of solitary metastatic lesions. Excision of such lesions may contribute to prolonged survival in selected instances.