SIU 2017: Management of Complex Renal Masses: Risk Benefit Trade-Off of Partial vs Radical Nephrectomy

Lisbon, Portugal (UroToday.com) Dr. Volpe presented on the management of complex renal masses, specifically weighing the risk/benefit ratio of partial and radical nephrectomy (PNx and Rnx, respectively). 

To start, he reviewed the major urology guideline recommendations. Surgery remains the mainstay of therapy for localized kidney cancer, particularly T1 and T2 diseases. There is strong evidence suggesting that partial nephrectomy is preferred for patients with T1 lesions. PNx should be prioritized for patients with T1 lesions, as well as for patients with solitary kidneys, bilateral masses, known familial RCC, preexisting CKD and proteinuria. It should also be considered for patients who are young or have comorbidities (HTN, diabetes) that may affect renal function in the future.
  • However, the evidence to support this is quite low, primarily based on retrospective cohort studies
  • None of the studies stratify patients by surgical complexity
  • However, in terms of incidence, the incidence of partial nephrectomy has been steadily rising, while the rate of radical nephrectomy has been decreasing
Factors that should be accounted for in the decision-making process:

1) Tumor factors
- Tumor complexity – Nephrometry scores, PADUA scores, C-index
- Histology and grade, biopsy pathology
- Tumor growth pattern and kinetics
- Tumor focality
- Tumor size

2) Patient factors
- Baseline renal function
- Comorbidities

3) Surgical factors
- Robotic surgery – advent has allowed easier/faster tumor excision, expansion of the indications for partial nephrectomy, shorter learning curve than laparoscopic partial nephrectomy; but only intermediate follow-up data is available and expensive

Evidence supporting Partial Nephrectomy
- Based mainly on retrospective series
- Oncologic outcomes have been shown to be the same between the two surgical options
- Only 1 randomized study in this space – EORTC study (Van Poppel et al)
  •     The estimated risk of death from RCC following NSS was not significantly higher than RNx (HR 2.06, CI 0.62-6.81, p = 0.23) – wide range due to small number of cancer deaths
  • In cT1 tumors up to 5 cm in size
  • NSS spares renal function – well established
  • Long-term functional outcomes of EORTC study – while eGFR is on average lower for patients undergoing RNx compared to NSS, neither group experiences a continued decline over time
  • Lower eGFR (particularly due to medical causes) is associated with higher rates of death, cardiovascular events and hospitalization
  • In studies accounting for confounding variables, such as diabetes and heart disease, patients with RNx still had higher rate of cardiovascular events and all-cause mortality
  • However, this benefit was NOT seen in the Van Poppel Randomized controlled trial (the only Level 1 evidence available)
  • May be due to bias of retrospective analysis – confirmed in a SEER study, in which patients undergoing NSS had better OS than patients not undergoing surgery at all!
  • Ultimately NSS likely preserves renal function, but does so without any evidence of OS benefit
  • Propensity matched analysis suggests some overall survival benefit for patients younger than 65
  • However, these benefits have to be balanced against the risk of positive surgical margins and leaving disease behind
  • In general, positive surgical margins may not equate to worse oncologic outcomes, in high-risk patients with positive surgical margins, rate of recurrence can be quite high (Shah et al)
Conclusions:

1) NSS is the gold standard treatment for treatment of localized pT1 tumors
2) It has comparable oncologic outcomes to RNx
3) It has better renal function sparing than RNx
4) It avoids progression to severe CKD in patients with solitary kidneys or baseline poor CKF
5) It may decrease the risk of cardiovascular deaths and all-cause mortality in selected patients


Presented by: Alessandro Volpe

Written by: Thenappan Chandrasekar, MD, Clinical Fellow, University of Toronto, Twitter: @tchandra_uromd at the 37th Congress of Société Internationale d’Urologie - October 19-22, 2017- Lisbon, Portugal
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