Q. A 70-year-old man is found to have a 2.5 cm exophytic right renal mass which is enhancing on CT imaging. He has normal renal function and wants to know his options. What would you advise him?
A. I would complete his staging and discuss his case in the uro-oncology MDT. I would see this patient in my clinic along with the cancer specialist nurse and review the images with him. His options are
1. Active surveillance of his small renal mass (SRM)
2. Surgery: partial nephrectomy or radical nephrectomy
3. Minimally invasive therapy: radiofrequency ablation or cryotherapy
Q. If the patient opts for active surveillance, how would you follow-up these patients in your practice?
A. Active surveillance of SRM can be defined as the initial monitoring of tumour characteristics by serial abdominal imaging with delayed intervention reserved for tumours showing clinical progression during follow-up. It has been shown that in the elderly and co-morbid patients with incidental SRM the cancer-specific mortality is low.
In Jewett’s series of active surveillance, SRMs had low growth rate and the progression to metastatic disease was reported in a small number [5]. Lane reported no overall survival advantage in between the two treatments (AS and surgery) in patients more than 75 years after adjusting for other variables [6].
Ttere fore, short- and intermediate-term oncological outcomes indicate that in selected patients active surveillance is appropriate, and can be followed by treatment for progression if required.
Q. What is your opinion on the role of biopsy for SRMs?
A. The role of ultrasound or CT-guided percutaneous biopsies for T1a tumours has gained popularity over the past decade. This is mainly due to the increased detection of SRMs (<4 cm). A biopsy should be considered if there is
Uncertainty regarding the nature of the lesion (e.g. lymphoma, suspected metastasis from another primary, lipid-poor AML)
Prior to systemic therapy (i.e. for metastatic RCC)
Prior to ablative therapy (radiofrequency ablation [RFA] or cryotherapy)
Prior to tumour surveillance
Richard et al. have recently published their 13 years’ experience on biopsies for SRMs and recommend that renal tumour biopsy (RTB) should be considered the initial step in the management of patients with radiographically indeterminate SRMs in whom a therapeutic approach is being considered. The first biopsy was diagnostic in 90% of cases and a repeat biopsy in 83% of non-diagnostic biopsies. When both were combined, RTBs yielded an overall diagnostic rate of 94%. Tumor size and exophytic location were significantly associated with biopsy outcome. RTB histology and nuclear grade were highly concordant with final pathology (more than 90%). Except for one, all adverse events (8.5%) were self-limiting [7].
In conclusion the current evidence points to the increasing use of renal tumour biopsies in indeterminate SRMs and I use this in my practice.
Q. If the patient is now considering surgery which modality would you offer him and why?
A. The EAU guidelines recommend that a partial nephrectomy should be offered to all patients with T1 tumours who do not have significant co-morbidity - hence I would offer this patient a partial nephrectomy (PN). This may be performed by either the open, laparoscopic or robotic-assisted technique.
Based on current available oncological and quality of life outcome studies, localised renal cancers are better managed by nephron-sparing surgery rather than radical nephrectomy (RN), irrespective of the surgical approach. The estimated 5-year cancer- specific survival (CSS) rates are comparable using these surgical techniques. In addition,
PN was demonstrated to better preserve general kidney function, thereby lowering the risk of development of metabolic or cardiovascular disorders. However, the patient should be counselled that a PN is associated with a higher percentage of positive surgical margins (PSMs) (8%) compared to RN. This may increase the risk of disease recurrence with the subsequent need for further intervention (local or systemic).
Q. What are the indications for nephron-sparing surgery?
A. Absolute indications are bilateral synchronous RCC, and an anatomical or functionally solitary kidney.
Relative indications are unilateral RCC with a reduced or poorly functioning contralateral kidney, unilateral RCC in patients with comorbidity associated with potential renal impairment (diabetes, renovascular disease), and patients with an increased risk of a second renal malignancy (hereditary RCC such as von Hippel-Lindau [VHL] disease).
Elective indications include localised unilateral RCC with a normal contralateral kidney.
Q. How would you consent a patient for laparoscopic partial nephrectomy?
A. I would explain that the aim of the procedure is to remove cancer while at the same time preserving kidney function.
I would use the British Association of Urological Surgeons (BAUS) procedure specific consent form which explains the procedure, the risks, the benefits and the alternatives. The procedure- specific complications include the need to convert to open, conversion to a radical nephrectomy, need for a second procedure or vascular intervention in the post-op period to control bleeding and chance of a urine leak needing further intervention (ureteric stent insertion).
I would explain that the risk of local recurrence is about 8% and complications (including bleeding and urinary leakage) are greater than with radical nephrectomy (this is particularly so with larger tumours).
Q. How does the follow-up following partial nephrectomy differ from the radical nephrectomies?
A. It is interesting to note that EAU guidelines recommend similar follow-up of patients who had partial nephrectomy for tumours less than 4 cm to those who underwent radical nephrectomy. I would discuss the case in my uro-oncology MDT and follow-up these patients based on their risk and status of their surgical margins as per my local cancer network guidelines.
Q. Are you aware of any alternative therapeutic approaches to surgery?
A. I am aware that both cryoablation and RFA have been used to treat T1a tumours (<4 cm). Both cryoablation and RFA can be performed using either a percutaneous or laparoscopic- assisted approach. When comparing cryoablation versus RFA, there is no significant difference for overall survival (OS), CSS or recurrence-free survival (RFS). Other ablative techniques such as microwave ablation, laser ablation and high-intensity ultrasound ablation have been used but are considered experimental.
Q. How do ablative techniques compare to partial nephrectomy?
A. Comparative studies looking at cryoablation and RFA versus partial nephrectomy have shown mixed results. Some studies have shown a higher local tumour recurrence rate in the RFA group when compared to PN but no difference regarding the occurrence of distant metastasis. Others have reported the metastasis-free survival was superior after PN and cryoablation compared to RFA for cT1a patients. The EAU guidelines recommendation is to offer surveillance, RFA or cryoablation to elderly and/or co-morbid patients with SRMs. Surgery should There fore be offered to younger/fit patients.