Cytoreductive nephrectomy is the surgical removal of the tumour to reduce the number of cancer cells (tumour burden), reduce the symptoms and immunosuppression caused by the tumour, and prevent medical complications, an important consideration for patients with advanced RCC. This study presented at the ASCO GU Symposium looked at the use of cytoreductive nephrectomy followed by combination immunotherapy in patients with metastatic RCC.
Around 10-20% of patients with RCC are diagnosed with growth of their tumour into a nearby vein, usually the renal vein and inferior vena cava. This is called a tumour thrombus. Outcomes for these patients are often poor. Although cytoreductive nephrectomy was considered a standard of care for patients with metastatic RCC, the introduction of targeted therapy and immunotherapy has cast doubt on the benefit of the surgery for patients with metastatic disease.
Analysis of patients with newly diagnosed metastatic RCC showed two important findings: First, patients with a tumour thrombus had similar outcomes after treatment with targeted therapy or immunotherapy medication to patients without a tumour thrombus. Second, cytoreductive nephrectomy, in addition to medication, seemed to lengthen survival times in these patients.
This study investigated these findings further. The study included 226 patients, 69% had cytoreductive nephrectomy plus medication and 31% had medication only. Twenty-eight per cent had tumour thrombus, 72% of whom had cytoreductive nephrectomy and medication, and 28% received medication only (usually a VEGF TKI).
When only medication was used to manage the disease without cytoreductive nephrectomy, there was no difference in average survival times for patients with and without tumour thrombus. Those patients who had tumour thrombus and cytoreductive nephrectomy survived significantly longer compared with those who did not (29.4 versus 12.1 months).
Due to the small numbers of patients and the retrospective design of this study, it cannot be considered as practice changing. Also, none of the patients with tumour thrombus who only received medication were not treated with immunotherapy. Because of the higher response rates with immunotherapy, it will be interesting to see if the benefit of cytoreductive nephrectomy to remove tumour thrombus is maintained in patients treated with immunotherapy combinations. A subgroup of patients with thrombus who have a good response to these combinations may be treated with immunotherapy alone.
Future work will involve looking at the effectiveness of immunotherapy combinations in patients with tumour thrombus and to identify imaging criteria that will predict the response of the thrombus to immunotherapy treatment.