Comparison of Oncological Outcomes for Hand-Assisted and Pure Laparoscopic Radical Nephroureterectomy: Results from the Taiwan Upper Tract Urothelial Cancer Collaboration Group - Beyond the Abstract

Although Upper tract urothelial cancer (UTUC) is relatively rare in Western countries, it accounts for about 20-30% of all urothelial cancers in Taiwan.1,2 This unusually high incidence of UTUC led the Taiwan Urological Association to establish the Taiwan Upper Tract Urothelial Cancer Collaboration Group with the aim of performing a retrospective nationwide survey of all patients with UTUC in Taiwan. In this study, we evaluated the oncological outcomes of 629 patients with UTUC who underwent hand-assisted or pure laparoscopic radical nephroureterectomy(LNU) at 9 hospitals in Taiwan.

Hand-assisted LNU is a modified method of pure LNU, which allows surgeons to introduce their hand into the operative field to perform blunt dissection and tactile sensation, which are rarely performed in pure laparoscopic surgery. However, whether the use of the hand-assisted or the pure laparoscopic approach has an effect on oncological outcomes remains unclear.

Because this was a retrospective study, there were some imbalanced confounding factors between the two groups. Some factors, such as lymphadenectomy, peri-operative chemotherapy and tumor grading, could significantly affect the results, the authors were concerned about whether the multivariate Cox proportional hazard model was good enough to adjust for these important imbalanced factors. So, in the current study, we adjusted the baseline covariant imbalance by inverse-probability of treatment weighting (IPTW), which was derived from the propensity scores.

The result showed that the performance of hand-assisted or pure LNU does not significantly affect the all-cause mortality, cancer-specific mortality, or extra-vesical recurrence for patients with non-metastatic UTUC. The hand-assisted approach only increases the risk of intravesical recurrence. We think the hand-manipulation during hand-assisted LNU increases intraluminal pressure in the upper urinary tract, which might cause tumor dissemination to the urinary bladder, but not to the surrounding tissue or vessels.

There were several limitations in the present study. First, this was a retrospective multi-institutional study. Heterogeneity in surgeon experience and clinical practice among hospitals, such as lymphadenctomy, peri-operative chemotherapy, follow-up protocol, or treatment choice for recurrence, can be confounding factors. Second, because of the multi-institutional study design, there was no single pathological review. Finally, there was some missing data in our study, especially “transperitoneal or retroperitoneal approach” and “bladder cuff menagement”. About 40% of the data was missing for these two variables making them unsuitable for multivariate analysis.

Written by: Chih-Chin Yu, Division of Urology, Department of Surgery, Taipei Tzu Chi Hospital, The Buddhist Medical Foundation, New Taipei City, Taiwan, School of Medicine, Buddhist Tzu Chi University, Hualien, Taiwan

References:

  1. Chou YH, Huang CH (1999) Unusual clinical presentation of upper urothelial carcinoma in Taiwan. Cancer 85:1342-1344
  2. Yang MH, Chen KK, Yen CC, Wang WS, Chang YH, Huang WJ, Fan FS, Chiou TJ, Liu JH, Chen PM (2002) Unusually high incidence of upper urinary tract urothelial carcinoma in Taiwan. Urology 59:681-687

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