management of small renal tumors dr. ngai ho yin division of urology department of surgery united...
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Management of Small renal tumors
Dr. NGAI Ho YinDivision of UrologyDepartment of SurgeryUnited Christian Hospital
Differential Dx of solid renal mass Most common:
Renal cell carcinoma
Less common: Oncocytoma Renal cortical adenoma AML
Rare: Neoplasm:
Transitional cell carcinoma Metastatic tumors
Infection: Renal abscess
Vascular Infarct Vascular malformation
Natural history of small renal tumor Meta-analysis from Uzzo et al. (2006) 234 enhancing renal masses From 9 series Mean follow-up: 34 months Mean initial size: 2.60cm
Mean growth rate 0.28cm/yr
Uzzo et al. The natural history of observed enhancing renal masses: Meta-analysis and review of the world literature. J Urol 175:425-431. Feb 2006
Analysis of Histology related to Tumor size ( Mayo clinic, from 1970-2000, n=2935 )Tumor Size % of Tumors that
were RCC% of RCC that were G3/G4
<1 cm (n=80) 54% 2%
1-4 cm (n=867) 79% 16%
4-7 cm (n=923) 90% 30%
>7 cm (n=1065) 94% 57%
Frank I et al. Solid Renal Tumors: an analysis of pathological features related to tumor size. J Urol 170:2217-2220. Feb 2003
Natural history of small renal tumor For single, small solid renal tumor
Almost 50% are benign if <1cm
Most will grow slowly, ~0.28cm/yr
size = chance of RCC & high grade disease
Aggressive potential of RCC increase after 3cm
Options
Observation Radical Nephrectomy Nephron-Sparing Surgery
Tumor Excision Open partial nephrectomy Laparoscopic partial nephrectomy
Tumor Ablation Laparoscopic cryoablation Radiofrequency ablation (RFA)
Radical nephrectomy
Gold Standard curative operation Described by Robson 1963
Surgical Principles Early ligation of the renal artery & vein Removal of the kidney outside Gerota’s fascia +/- Removal of ipslateral adrenal gland +/- Complete lymphadenectomy from the crus of diaphr
agm to aortic bifurcation
Nephron Sparing Surgery
Goal of NSS:1. Complete oncological excision of tumor with
minimal technical complications
2. Optimal functional preservation for renal remnant
Indication
Nephron Sparing SurgeryOpen partial nephrectomy
Data from 3 major centers including: Cleveland clinic Hafez KS, Novick AC, Butler BP. Management of small solitary unilateral renal cell
carcinomas: impact of central versus peripheral tumor location. J Urol 1998;159:1156–60
Mayo clinic Lerner SE, Hawkins CA, Blue ML, et al. Disease outcome in patients with low stage renal cell carcinoma treated with nephron sparing or radical surgery. J Urol 2002;167:884–9.
Memorial Sloan-Kettering Cancer Center Lee CT, Katz J, Shi W, Thaler HT, Reuter VE, Russo P. Surgical management of renal tumors 4 cm or less in a contemporary cohort. J Urol 2000;163:730–6.
NSS and radical nephrectomy provide equally effective curative treatment for single, small (<=4cm) localized RCC
Nephron Sparing Surgery Open partial nephrectomy Novick AC. Laparoscopic and partial nephrectomy. Clin Cancer Res 2004; 10:6322S-7S
• Review of 1262 patients with open NSS for RCC since 1990
• Mean Cancer-specific survival for all patients undergoing open NSS for localized RCC 88% to 97.5% at Mean Follow-up 4-6 years
Nephron Sparing Surgery Open partial nephrectomy Benefit in decreasing risk of progression
to chronic renal insufficiency and ESRF Memorial Sloan-Kettering Cancer Center McKiernan J, Simmons R, Katz J,
Russo P. Natural history of chronic renal insufficiency after partial and radical nephrectomy. Urology 2002;59:816–20.
Mayo clinic Lau WK, Blute ML, Weaver AL, Torres VE, Zincke H. Matched comparison of radical nephrectomy vs nephron-sparing surgery in patients with unilateral renal cell carcinoma and a normal contralateral kidney. Mayo Clin Proc 2000;75:1236–42.
Renal insufficiency (Increase in Serum Cr >2mg/dl) At 10 years time :
12.4% in radical nephrectomy group 2.3% in NSS group
Nephron Sparing Surgery Open partial nephrectomy
Gold standard in nephron-sparing surgery
Comparable efficacy, morbidity & mortality as radical nephrectomy
Additional benefit in renal preservation
Nephron Sparing Surgery Laparoscopic partial nephrectomy Largest single institutional report of LPN by
Gill et al. Comparative analysis of laparoscopic versus open partial nephrectomy for renal tumors in 200
patients. Journal of Urology. 170(1):64-8, 2003 Jul.
Patients with solitary renal tumor (<=7cm) in size ( clinical T1 RCC ) LPN (n=100) : Sept 1999 to Jan 2002 OPN (n=100) : Apr 1998 to May 2001
Nephron Sparing Surgery Laparoscopic partial nephrectomy
Lap PN Open PN
Blood loss 125ml 250ml p<0.001
Morphine equivalent
20.2mg 252.5mg p<0.001
Hospital stay 2 days 5 days p<0.001
Convalescence 4 weeks 6 weeks p<0.001
Nephron Sparing Surgery Laparoscopic partial nephrectomy
Intra-op Complications Lap PN Open PN
Renal haemorrhage 3 0
Ureteral resection 1 0
Post-op Complications
Urine leakage3 1
Perirenal haematoma1 0
Renal haemorrhage,
Embolization1 0
Renal haemorrhage,
Nephrectomy1 0
Haematuria1 0
Ureteropelvic obstruction 0 1
Total 11 2 p=0.01
Nephron Sparing Surgery Laparoscopic partial nephrectomy Oncological efficacy of LPN by Allaf et al.
( John Hopkins Medical institution – 3-year follow-up)
48 patients with RCC (Mean tumors size 2.4cm) treated by LPN Intra-op FS margin : all negative Mean FU 37.7 months Final pathology:
42 patients : pT1 6 patients : pT3a
Laparoscopic partial nephrectomy: evaluation of long-term oncological outcome. Journal of Urology. 172(3):871-3, 2004 Sep.
Nephron Sparing Surgery Laparoscopic partial nephrectomy Results :
No recurrence in 46 patients 1 patient with VHL locally recurred at 18th months 1 patient recurred at new location of same kidney
at 4 yrs time
Nephron Sparing Surgery Laparoscopic partial nephrectomy Benefits from LPN:
Less blood loss Less analgesic requirement Shorter hospital stay Shorter convalescence Short term data suggesting promising survival outcomes
Problems of LPN: Longer warm ischaemic time More major intra-op & post-op urological Cx No long term data concerning the oncological efficacy
Laparoscopic NSS is an effective treatment for clinically small localized RCC despite long term result needed.
Nephron Sparing SurgeryLaparoscopic Cryoablation Method:
Usage of a liquid nitrogen-cooled cryoprobe At temperature of –40 ‘C
By dual freeze-thaw cycle Direct cellular injury &
Indirect damage to microvasculature To ablate normal and cancerous tissues
Problems : No histopathology to assume clearance May Need extra biopsy for margin clearance
Nephron Sparing SurgeryLaparoscopic Cryoablation Gill et al. Renal cryoablation: outcome at 3 years. Journal of Urology. 173(6):1903-7, 2005 Jun.
3 yrs results 56 patients with small renal tumors
75% reduction in mean cryolesion size at 3 years 38% (17 lesions) completely disappeared Post-op needle biopsy: residual tumor in 2 patients
3 years Cancer-specific survival ( unilateral sporadic renal tumor ) = 98%
Nephron Sparing SurgeryLaparoscopic Cryoablation Laparoscopic Cryoablation:
Technically safe and intermediate results are encouraging
Longer term follow-up needed for oncological efficacy of cryoablation
Nephron Sparing SurgeryRadio Frequency Ablation
Using a RFA needle (Percutaneous> open / laparoscopic)
Deliver high-frequency alternating current to cancerous tissue
Induce ionic agitation frictional heat intracellular temperature (60-100 ํC) Desiccation, Cellular protein denaturation and me
mbrane disintegration
Nephron Sparing SurgeryRadio Frequency Ablation
Rendon et al. 11 renal tumors RFA Immediate / Delayed nephrectomy Found viable cancer cells in specimen :
4/5 (80%) [immediate group] 3/6 (50%) [delayed group]
Nephron Sparing SurgeryRadio Frequency Ablation
Michaels et al. 20 renal tumors (mean 2.4cm) in 15 pts RFA Open Partial Nephrectomy Results:
All 20 specimens had evidence of morphologically unchanged tumors
Nephron Sparing SurgeryRadio Frequency Ablation
Current RFA regimens:
Ineffective for total destruction of renal tumor tissue in a significant number of patients.
Still experimental in treatment of RCC
Conclusion For small solid renal tumor <= 4cm
Most are RCC
Evidence suggested NSS is equally effective as radical nephrectomy
NSS with better preservation of renal functions in long term
OPN is the gold standard among choices of NSS
LPN is promising technique with its potential advantages