Page 7 - Kidney Cancer Research Network of Canada (KCRNC) consensus statement on the role of cytoreductive nephrectomy for patients with metastatic renal cell carcinoma

CUAJ – Consensus Statement Mason et al
KCRNC consensus: Cytoreductive nephrectomy for mRCC

cytoreductive nephrectomy performed in the interferon era did not include information on
histologic subtypes [1, 2], and all three of the modern TKI era phase 3 trials investigating
CN in mRCC have excluded patients with non-clear cell mRCC[4, 48, 49]. Despite this,
limited observational data do suggest that CN may provide a survival advantage in
patients with non-clear mRCC[7, 13, 50-53]. In a recent population based study from the
SEER database including 575 patients with non-clear cell mRCC who underwent CN and
276 who did not, cancer-specific mortality was significantly lower in patients receiving
CN after controlling for available confounders (multivariable HR 0.38; 95% CI 0.30 –
0.47)[50]. Furthermore, a subgroup analysis demonstrated that CN was associated with
an improvement in survival among all investigated non-clear cell histological subtypes
(chromophobe, papillary, and collecting duct mRCC)[50]. In addition, a recent
retrospective study from the IMDC including 353 patients with papillary mRCC noted
that patients who underwent CN had an improved OS compared to those who did not
undergo CN (HR 0.62; 95% CI 0.45-0.85)[54]. Three additional observational studies
have reported similar findings [7, 13, 52]. Thus, recognizing very limited data, we
suggest that patients with non-clear cell mRCC may be offered CN with similar
indications and contraindications to those with clear cell mRCC.

Is there a role for biopsy prior to cytoreductive nephrectomy?

1. In patients receiving initial systemic therapy, biopsy of the primary lesion or a
metastatic deposit should be performed prior to the initiation of therapy.
2. For patients receiving upfront CN, pre-operative biopsy of the kidney tumour or
metastatic deposit may be performed if the results of the biopsy will influence
management.

In patients proceeding to initial systemic therapy, histologic diagnosis is required in
order to guide appropriate systemic treatment. Nonetheless, in a patient with clear
evidence of mRCC who is proceeding to upfront CN, biopsy is not absolutely indicated.
As noted above, CN appears to play a role in treating non-clear cell mRCC, and
appropriately selected patients can thus proceed directly to CN without a biopsy.
However, if a non-RCC histology is questioned (e.g. radiographic characteristics
suggestive of urothelial carcinoma, lymphoma, etc.), a biopsy prior to CN should be
performed as the results may significantly alter the patient’s subsequent management.