The nodal status and management is the key determinant for survival in penile cancer.
Superficial then deep inguinal nodes are the first port of drainage – this can be unilateral or bilateral.
The sentinel lymph nodes appear to be usually in the medial superior zone, followed by central inguinal nodes.
No direct drainage has been reported to inferior inguinal nodes or pelvic nodes without involving the sentinel inguinal nodes first.
Likewise, pelvic nodes do not become involved without ipsilateral inguinal nodes being involved first.
Early lymphadenectomy improves survival but is associated with significant morbidity.
In clinically node-negative (cN0 / non palpable) patients – micrometastatic disease may be present in the nodes in 20 – 25 %.
In clinically node-positive (cN1 / palpable) patients at least 50 – 70 % will have metastatic disease.
EAU – “the notion that (palpable nodes) may be inflammatory and that antibiotic treatment should be used first is unfounded and dangerous as it delays curative treatment”.
Morbidity for inguinal lymphadenectomy may approach 50 %.
Updated 2023 EAU guideline
US/FNA first – not very sensitive but very specific – if positive for cancer, straight to full ILND.
Dynamic sentinel node biopsy is recommended first line surgical staging – only for staging LND if referral not available or patient strongly prefers LND.
FDG PET preferred for cN+ patients (and FNA) prior to starting treatment.
Dynamic sentinel lymph node biopsy
Aims to detect the sentinel node in both groins.
The primary tumour (or scar) is injected with technetium-99m labelled colloid the morning of or day prior to surgery. Patent blue injected peri-operatively. May also get SPECT-CT or lymphoscintigraphy from radiologist showing location of sentinel node.
A handheld gamma probe is used intra-operatively in conjunction with the blue dye and the sentinel node is excised and analysed with frozen section – if negative, the patient is spared a superficial or modified inguinal node dissection.
Sensitivity may be around 85 – 90 %, with false negatives as high as 10 %.
Modified (superficial) inguinal lymph node dissection
Aims to reduce the morbidity associated with traditional ILND by limiting dissection to the lymph node packet superficial/superior to the fascia lata.
Important to remove the medial superficial inguinal lymph nodes and the central zone.
The greater saphenous vein can be left alone.
Reduces morbidity to 25 – 30 %.
False negative rate of modified ILND is unknown.
Both sentinel node biopsy and modified superficial LND may miss micro-metastatic disease.
Prognosis is worse for patients in whom nodal disease is detected clinically on surveillance (40 %), cf. those who were diagnosed early without clinically evident disease (90 %).
Pelvic lymph node dissection
Those at risk are those with multiple involved inguinal nodes (>3) or extranodal extension of inguinal nodes.
PLND is most often a staging procedure to identify pN3 disease and identify candidates for adjuvant therapy – may represent therapeutic effect / curative treatment in some patients.
cN3 disease / fixed nodal mass
Neoadjuvant chemotherapy – pathological complete response seen in only 10 %.
- TIP – paclitaxel, Ifosfamide, cisplatin
- Or cisplatin & 5-FU
Surgery first results in large defects, flap reconstructions, long hospital stays and high complications, which may delay or result in problems with chemotherapy.
Patients who respond to neoadjuvant chemo can then undergo LND 5 – 8 weeks after finishing chemotherapy, with complete open ILND +/- fixed skin excision.
- If clinically pelvic nodes involved, bilateral PLND.
- If pelvic nodes not involved in imaging, simultaneous ipsilateral PLND.