Modified Inguinal Lymph Node Dissection in Groin-Negative Patients of Penile Cancer: Our Experience

Systematic Review and Meta-analysis of Minimally Invasive Procedures for Surgical Inguinal Nodal Staging in Penile Carcinoma

CONTEXT

There are several procedures for surgical nodal staging in clinically node-negative (cN0) penile carcinoma.

OBJECTIVE

To evaluate the diagnostic accuracy, perioperative outcomes, and complications of minimally invasive surgical procedures for nodal staging in penile carcinoma.

EVIDENCE ACQUISITION

A systematic review of the Medline, Embase, and Cochrane controlled trials databases and ClinicalTrials.gov was conducted. Published and ongoing studies reporting on the management of cN0 penile cancer were included without any design restriction. Outcomes included the false negative (FN) rate, the number of nodes removed, surgical time, and postoperative complications.

EVIDENCE SYNTHESIS

Forty-one studies were eligible for inclusion. Four studies comparing robot-assisted (RA-VEIL) and video-endoscopic inguinal lymphadenectomy (VEIL) to open inguinal lymph node dissection (ILND) were suitable for meta-analysis. A descriptive synthesis was performed for single-arm studies on modified open ILND, dynamic sentinel node biopsy (DSNB) with and without preoperative inguinal ultrasound (US), and fine-needle aspiration cytology (FNAC). DSNB with US + FNAC had lower FN rates (3.5-22% vs 0-42.9%) and complication rates (Clavien Dindo grade I-II: 1.1-20% vs 2.9-11.9%; grade III-V: 0-6.8% vs 0-9.4%) in comparison to DSNB alone. Favourable results were observed for VEIL/RA-VEIL over open ILND in terms of major complications (2-10.6% vs 6.9-40.6%; odds ratio [OR] 0.18; p < 0.01). Overall, VEIL/RA-VEIL had lower wound-related complication rates (OR 0.14; p < 0.01), including wound infections (OR 0.229; p < 0.01) and skin necrosis (OR 0.16; p < 0.01). The incidence of lymphatic complications varied between 20.6% and 49%.

CONCLUSIONS

Of all the surgical staging options, DSNB with inguinal US + FNAC had the lowest complication rates and high diagnostic accuracy, especially when performed in high-volume centres. If DSNB is not available, favourable results were also found for VEIL/RA-VEIL over open ILND. Lymphatic-related complications were comparable across open and video-endoscopic ILND.

PATIENT SUMMARY

We reviewed studies on different surgical approaches for assessing lymph node involvement in cases with penile cancer. The results show that a technique called dynamic sentinel node biopsy with ultrasound guidance and fine-needle sampling has high diagnostic accuracy and low complication rates. For lymph node dissection in penile cancer cases, a minimally invasive approach may offer favourable postoperative outcomes.

Radioisotope-Guided Sentinel Lymph Node Biopsy in Penile Cancer: A Long-Term Follow-Up Study

Lymph node (LN) management is critical for survival in patients with penile cancer. However, radical inguinal lymphadenectomy carries a high risk of postoperative complications such as lymphedema, lymphocele, wound infection, and skin necrosis. The European Association of Urology guidelines therefore recommend invasive LN staging by modified inguinal lymphadenectomy or dynamic sentinel node biopsy (DSNB) in clinically node-negative patients (cN0) with intermediate- and high-risk tumors (≥ T1G2). However, the timing of DSNB (simultaneous vs. subsequent to partial or total penile resection) is controversial and the low incidence of penile cancer means that data on the long-term outcomes of DSNB are limited. The present study aimed to analyze the reliability and morbidity of DSNB in patients with penile cancer during long-term follow-up. This retrospective study included 41 patients (76 groins) who underwent radioisotope-guided DSNB simultaneously or secondarily after penile surgery from June 2004 to November 2018. In total, 193 sentinel LNs (SLNs) and 39 non-SLNs were removed. The median number of dissected LNs was 2.5 (interquartile range 2-4). Histopathological analysis showed that five of the 76 groins (6.6%) contained metastases. None of the non-SLNs were tumor-positive. In accordance with the guidelines, all inguinal regions with positive SLNs underwent secondary radical inguinal lymphadenectomy, which revealed three additional metastases in one groin. Regional LN recurrence was detected in three patients (four groins) during a median follow-up of 70 months, including two patients in whom DSNB had been performed secondarily after repetitive penile tumor resections. DSNB-related complications occurred in 15.8% of groins. Most complications were mild (Clavien-Dindo grade I; 50%) or moderate (II; 25%), and invasive intervention was only required in 3.9% of groins (IIIa: n = 1; IIIb: n = 2). In summary, this study suggests that the current radioisotope-guided DSNB procedure may reduce the complication rate of inguinal lymphadenectomy in patients with cN0 penile cancer. However, DSNB and penile surgery should be performed simultaneously to minimize the false-negative rate. Recent advances, such as new tracers and imaging techniques, may help to reduce the false-negative rate of DSNB further.