Surgical Advances in Inguinal Lymph Node Dissection: Optimizing Treatment Outcomes: Beyond the Abstract

Although penile cancer is rare in North America, it remains one of the most common genitourinary malignancies in the developing world.  Due to its rarity in the United States, the surgical management of high-risk or advanced penile cancer remains understudied and not well-known.  This is, however, an exciting time in this field of study, as new advances in imaging, minimally-invasive surgery, and increased utilization of multimodal therapy has attempted to decrease the morbidity and mortality from this disease.  In our manuscript, we sought to provide an overview of recent advances in the surgical management of penile cancer, specifically focusing on high-risk patients in need of inguinal lymphadenectomy for both appropriate staging and treatment of their disease.  

Although physical examination remains a mainstay in the clinical evaluation of these patients, 18F-fluorodexoyglucose (FDG) PET-CT has emerged as an important tool in the staging of high-risk penile cancer, especially in patients with clinically palpable nodes to confirm presence of disease (sensitivity >95%).  Additionally, the traditional teaching of administering antibiotic therapy before inguinal lymph node dissection (ILND) in patients with palpable groins in no longer recommended due to the increased utilization of needle or excisional biopsy in questionable cases, which provide a more immediate diagnosis.

Bilateral ILND continues to be recommended in patients with high-risk primary penile tumors (high-grade, >pT1b) due to the 20 – 30% risk of micro-metastatic disease in patients with clinically normal groins.  Delaying ILND in this scenario until groins become clinically positive results in worse long-term oncological outcomes.  While traditional ILND has a high overall morbidity due to the risk of wound infection, skin necrosis, chronic scrotal or lower extremity lymphedema, or development of venous thrombosis, modifications to the surgery with preservation of the saphenous vein and fascia lata, limiting the areas of dissection, and elimination of the Sartorius muscle transposition have decreased complication rates.  It is important to remember, however, that conversion to radical ILND is required in the presence of positive inguinal metastatic disease as the false-negative rate for modified ILND is unknown.    

Video endoscopy ILND (VEIL) and robotic-assisted ILND have also attempted to minimize the morbidity of surgery in high-risk penile cancer patients, replicating the open surgical principles using a minimally-invasive platform.  Ideally-suited candidates should have clinically negative groins, and initial studies have shown a decrease in wound-related complications after surgery.  Larger, prospective studies with longer-term follow-up, however, are necessary to validate these endoscopic surgical approaches and demonstrate oncological equivalence with traditional treatments.      

Pelvic lymph node dissection (PLND) may also play a role in the surgical management of advanced penile cancer.  Approximately 20 – 30% of patients with inguinal metastatic disease will have spread to the pelvic lymph nodes (LNs).  PLND, therefore, is recommended for penile cancer patients with >2 positive inguinal LNs or inguinal extracapsular extension (ECE) either in the same or separate operative setting as ILND.  Prophylactic PLND in patients with micro-metastatic pelvic nodal disease may have curative potential with reported long-term, disease-free survival rates of 16 – 20%.  Patients with clinically enlarged pelvic LNs on cross-sectional imaging, however, benefit from neoadjuvant chemotherapy followed by post-chemotherapy inguinal and pelvic lymphadenectomy only in clinical responders.      

Delayed (>1 year after treatment of the primary penile tumor) inguinal recurrence of penile cancer in the absence of occult distant metastatic disease may also be amendable to curative surgical treatment via ipsilateral salvage ILND, but complication rates remain high in this setting with the required use of alternative flaps or skin grafts (i.e. rectus abdominis myocutaneous flap) due to the frequent lack of soft tissue or skin coverage overlying the surgical bed.  

In conclusion, ILND for high-risk or locally advanced penile cancer has evolved over the last decade with the increased utilization of preoperative imaging and multimodal therapy to better define and optimize surgical treatment.  Adoption of smaller templates for dissection and minimally-invasive technology have also reduced patient morbidity from overly extensive surgery without compromising oncological outcomes.

Written by: Pranav Sharma, MD
1Philippe E. Spiess, MD, MS2

1Department of Urology, Texas Tech University Health Sciences Center, Lubbock, TX
2Department of Genitourinary Oncology, Moffitt Cancer Center, Tampa, FL

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