Reliability of dynamic sentinel node biopsy combined with ultrasound-guided removal of sonographically suspicious lymph nodes as a diagnostic approach in patients with penile cancer with palpable inguinal lymph nodes

A proposed Clino-radio-pathological Risk Scoring System (CRiSS) for prediction and management of inguinal lymph-nodes metastasis in squamous cell carcinoma of the penis

OBJECTIVE

To develop a risk scoring system for prediction of inguinal lymph-node involvement and to suggest a management strategy according to the risk groups based on clinical, radiological and pathological parameters in squamous cell carcinoma (SCC) of penis.

MATERIALS AND METHODS

A retrospective analysis of all patients of SCC penis from 2014 to 2020 at our institute was done. The patients were divided into derivation cohort (2014 to 2019) and validation cohort (2019 to 2020). A total of 10 predictors were analysed in univariate analysis and those found significant were further subjected to multivariate analysis to derive regression coefficient for each. CRiSS scores were assigned based on the coefficients and three groups were created which were correlated with nodal metastasis. The predictive accuracy of the model was assessed by ROC analysis of the derivation cohort and validation cohort.

RESULTS

A total of 102 patients were identified in derivation cohort and 23 patients in validation cohort. Size of the primary >3cm, ulceroinfiltrative growth, involving shaft, ultrasound size of lymph-nodes >1cm, loss of fatty hila, moderate and poor differentiation, and lypmphovascular/perineural invasion were independent predictors of inguinal lymphnode metastasis in multivariate analysis. CRiSS could achieve AUROC of .910 and .887 in derivation and validation cohort respectively. The rate of metastatic lymphadenopathy was 0%, 41.4%, and 89.5% in low, intermediate, and high-risk groups respectively.

CONCLUSIONS

CRiSS can effectively predict inguinal lymph-node metastasis in SCC penis. We suggest a management strategy based on risk groups that will avoid morbidity of groin dissection in many patients.

Nomograms to predict the presence and extent of inguinal lymph node metastasis in penile cancer patients with clinically positive lymph nodes

Background

We developed two nomograms to predict the presence of inguinal lymph node metastasis (ILNM) and two or more histologically positive inguinal lymph nodes (ILNs) or one ILN with extranodal extension (ENE) in penile cancer patients with clinically positive inguinal lymph nodes (ILNs).

Methods

This study enrolled 75 penile squamous cell carcinoma (PSCC) patients with clinically positive ILNs. A binary logistic regression model was taken to screen out the risk factors for the presence of ILNM and two or more positive ILNs or one node with ENE in one side. Nomograms were plotted based on the results of multivariate logistic regression analysis.

Results

Our multivariate analysis demonstrated that the pathological grade, lymphovascular invasion (LVI), and short diameter (SD) of the largest ILN were independent risks. The bootstrap-corrected concordance index of the nomogram for the presence of ILNM was 0.948, and 0.878 for two or more histologically positive ILNs or one ILN with ENE on one side.

Conclusions

By incorporating tumor pathological grade, LVI and SD of the largest ILN, our nomograms can efficiently predict the ILNM in penile cancer patients with clinically positive nodes.

Detection of lymph node metastases in penile cancer

Penile cancer (PC) is a relatively rare malignancy in the United States (US) but a greater concern in developing nations. Lymph node imaging remains critical to the staging and treatment of this disease as metastases develop in a predictable, anatomic fashion. Early surgical intervention remains a mainstay in treatment and imaging often aids in decision making. This review highlights the indications for imaging in both low-stage and advanced disease. Furthermore, we discuss the benefits and limitations of currently available imaging for staging of inguinal and pelvic lymph nodes in PC and novel modalities in development.

Advancements in staging and imaging for penile cancer

PURPOSE OF REVIEW

We review recent advancements in staging and imaging of penile cancer, including surveillance after therapy.

RECENT FINDINGS

For cN0 patients, the sentinel lymph node biopsy is currently considered the preferred way for invasive staging. It has largely replaced other modalities such as staging inguinal lymphadenectomy. Its diagnostic value increases when combined with other staging modalities such as ultrasound with fine-needle aspiration cytology (US-FNAC) or fluorodeoxyglucose-PET with computed tomography (PET/CT). In patients with palpably suspicious nodes (cN+), imaging is more useful. PET/CT has shown good accuracy in a limited number of small studies. US-FNAC can confirm nodal metastatic disease. A staging inguinal lymphadenectomy is of therapeutic value but is associated with significant morbidity. Omitting staging inguinal lymphadenectomy was recently described; one study showed well tolerated use of sentinel lymph node biopsy combined with intraoperative ultrasound-guided resection of suspicious nodes in cN+ patients. Therapeutic inguinal lymphadenectomy was only performed in the 42% of groins with metastases confirmed by disorder. For M-staging, PET/CT has shown good sensitivity, and its role should be further evaluated. Follow-up and surveillance rely on physical examination and US-FNAC.

SUMMARY

Over the past decade, staging and treatment of penile cancer have become less invasive, while survival tends to improve.

[Long-term results of sentinel node biopsy diagnostics in penile carcinoma : Dynamic sentinel node biopsy in cases with nonpalpable lymph nodes in the groin]

OBJECTIVE

Dynamic sentinel node biopsy (DSNB) has been recommended in the EAU guidelines for several years as a minimally invasive method for lymph node staging in patients with penile carcinoma and nonpalpable lymph nodes. However, due to the high methodological demands and the primarily unreliable results, this method is rarely used in Germany. The aim of this study was to establish the reliability and morbidity of this method.

MATERIAL AND METHODS

The frequency of lymph node recurrent disease and complications were prospectively recorded in patients with initially nonpalpable inguinal lymph nodes and histologically negative sentinel lymph nodes. Quality criteria were the false negative rate (percentage of lymph node recurrence in negative procedures) and the morbidity rate. Inguinal regions with palpable lymph nodes and/or evidence of metastases were not considered.

RESULTS

The study included 37 patients with histologically negative sentinel lymph nodes in 63 groins with nonpalpable inguinal lymph nodes. There were 21 T1(a/b) stages, 10 T2, and 6 T3 stages. Tumor differentiation was good in 4, moderate in 26, and poor in 7 patients. During a median follow-up of 52 months (range 1-131 months), we observed a bilateral lymph node recurrence in 1 patient and a conservatively managed prolonged lymphorrhea in another patient. Per inguinal region the false-negative rate was 3.2 % and the morbidity rate was 1.6 %; seen per patient the rates were both 2.7 %.

CONCLUSIONS

DSNB is a reliable method of lymph node staging in patients with penile carcinoma and nonpalpable inguinal lymph nodes. The high degree of reliability in combination with the low morbidity justifies the higher methodical complexity of this method.