Metastases to the kidney: a comprehensive analysis of 151 patients from a tertiary referral centre

To describe the presentation, treatment and outcomes of patients with metastatic tumours to the kidney treated at a tertiary referral centre.

We retrospectively identified 151 patients diagnosed with a primary non-renal malignancy with renal metastasis. Clinical, radiographic and pathological characteristics were assessed. Overall survival (OS) was calculated using Kaplan-Meier methods.

The median patient age was 56.7 years. The most common presenting symptoms were flank pain (30%), haematuria (16%) and weight loss (12%). Most primary cancers were carcinomas (80.8%). The most common primary tumour sites were lung (43.7%), colorectal (10.6%), head and neck (6%), breast (5.3%), soft tissue (5.3%) and thyroid (5.3%). Renal metastases were typically solitary (77.5%). Concordance between radiologist and clinician imaging assessment was 54.0%. Three ablations and 48 nephrectomies were performed. For non-surgical patients, renal metastasis diagnosis was made with fine-needle aspiration or biopsy. The median OS from primary tumour diagnosis was 3.08 years and the median OS from time of metastatic diagnosis was 1.13 years. For patients treated with surgery, median OS from primary tumour diagnosis was 4.81 years, and OS from metastatic diagnosis was 2.24 years.

Metastases to the kidney are a rare entity. Survival appears to be longer in patients who are candidates for and are treated with surgery. Surgical intervention in carefully selected patients with oligometastatic disease and good performance status should be considered. A multidisciplinary approach with input from urologists, oncologists, radiologists and pathologists is needed to achieve the optimum outcomes for this specific patient population.