Value of PET and PET/CT in the diagnostics of prostate and penile cancer

Penile cancer: Clinical Practice Guidelines in Oncology

Squamous cell carcinoma of the penis represents approximately 0.5% of all cancers among men in the United States and other developed countries. Although rare, it is associated with significant disfigurement, and only half of the patients survive beyond 5 years. Proper evaluation of both the primary lesion and lymph nodes is critical, because nodal involvement is the most important factor of survival. The NCCN Clinical Practice Guidelines in Oncology for Penile Cancer provide recommendations on the diagnosis and management of this devastating disease based on evidence and expert consensus.

Update in the surgical principles and therapeutic outcomes of inguinal lymph node dissection for penile cancer

OBJECTIVES

Inguinal lymph node dissection (ILND) for the treatment of metastatic penile squamous cell carcinoma (SCC) has historically been associated with significant morbidity. This review addresses the surgical principles and techniques to decrease its perioperative morbidity, while optimizing its oncologic outcomes.

MATERIALS AND METHODS

A review of the English scientific literature from 1966 to present was conducted using the PubMed search engine as well as of additional cited works not initially noted in the search using as keywords penile cancer, inguinal lymph node dissection, inguinal lymph node metastasis, morbidity, and complications.

RESULTS

The contemporary outcomes of ILND in the context of penile cancer have built on the significant contributions made by surgeons and scientists worldwide. In this review, we provide a comprehensive overview of the principles of ILND optimizing oncological outcomes, while minimizing its attributable morbidity. It is hoped this review will serve as a benchmark for clinicians to approach this often highly aggressive tumor phenotype.

CONCLUSIONS

ILND remains an important diagnostic and therapeutic procedure for patients with penile SCC, as contemporary ILND series have reported a decrease in its associated morbidity, with the potential for further treatment outcomes in years to come. ILND can in appropriately selected patients render them disease-free, thus justifying its associated morbidity.

Penile cancer: management of regional lymphatic drainage

Presence and magnitude of the inguinal nodal metastases are the most important determinants of oncologic outcome in patients with squamous carcinoma of the penis (SCP). Surgical removal of the inguinal lymph nodes provides an important staging and therapeutic benefit to SCP patients, while the methodology of appropriate patient selection for lymph node dissection continues to evolve. Compliant, motivated, and reliable patients with low risk of harboring metastatic inguinal lymph nodes can be managed with careful inguinal surveillance. In SCP patients whose primary tumors demonstrate pathologic features of aggressive disease, modified bilateral inguinal lymph node dissection should be performed and converted to classic ilioinguinal lymph node dissection if metastatic disease is confirmed on frozen sections. Patients with bulky inguinal metastases are unlikely to be cured by surgery alone. Integration of systemic therapy, especially in a presurgical setting, is an attractive strategy for management of patients with advanced SCP, and is currently being studied prospectively.

Lymphadenectomy in the surgical management of penile cancer

CONTEXT

Uncertainty remains about the extent and indications for inguinal lymphadenectomy in penile cancer, a procedure known for relatively high morbidity. Several attempts have been made to develop strategies which can improve the diagnostic quality and reduce the morbidity of the management of inguinal lymph nodes in penile cancer.

OBJECTIVE

To analyse the existing published data on the surgical management of inguinal nodes in penile cancer regarding morbidity and survival.

EVIDENCE ACQUISITION

A Medline search was performed of the English-language literature (1966-September 2008) using the MeSH terms penile carcinoma, lymph node dissection, lymphadenectomy, and complications.

EVIDENCE SYNTHESIS

Lymph node metastases are frequent in penile cancer, even in early pT1G2 stages. Since the results of systemic treatment of advanced penile cancer are disappointing, complete dissection of all involved lymph nodes is highly recommended. The extent of lymph node dissection should be adapted to clinical stage, as this corresponds to metastatic spread. For low-risk patients (pTis, pTa, and pT1G1) without palpable lymph nodes and with good compliance, a surveillance strategy may be chosen. For all other patients without palpable lymph nodes (including intermediate risk pT1G2 disease), a modified bilateral lymphadenectomy is recommended. An alternative to this is a dynamic sentinel lymph node biopsy in specialised centres. All patients with histologically proven lymph node metastases should undergo radical inguinal lymphadenectomy. Pelvic lymph node dissection should be done in all patients with more than two metastatic inguinal lymph nodes. In case of fixed inguinal lymph nodes, neoadjuvant chemotherapy is recommended, followed by node resection.

CONCLUSIONS

Lymphadenectomy is an integral part of the management of penile cancer, since early dissection of involved lymph nodes improves survival.

[PET-FDG in metastases from urological malignancies]

FDG-PET is useful for both topographic and metabolic analysis of metastatic cells. It uses a radioactive metabolite integrated into a molecule which penetrates into the tumoral cells. At present, concerning urologic carcinoma, there is no indication for its use in routine to diagnose primary tumors or to explore their development. However it can be useful for minor recurrences for which CT scan and MRI cannot be conclusive. In particular for kidney and urothelial carcinoma it may represent a diagnostic benefit. Nevertheless, interpretation is often made difficult by tracer urinary excretion. New radio tracers are being tested and will probably lead to new indications. Research on androgen receptors and molecular imaging is ongoing.

[Metastases from squamous cell carcinoma of the penis]

Penile cancer is a rare carcinoma and visceral metastases are uncommon. Metastasis diagnosis is carried out with TDM and MRI but markers can sometimes be helpful (ie SSCAg). There is no referent chemotherapy, a trial has been started (CAVER).

Non-invasive and minimally invasive staging of regional lymph nodes in penile cancer

INTRODUCTION

The management of the regional lymph nodes in penile cancer patients, particularly when these lymph nodes are impalpable, remains controversial. Prophylactic bilateral inguinal lymphadenectomy is associated with high morbidity and is often unnecessary. However, there is no non-invasive or minimally invasive staging technique that can determine the lymph node status of penile cancer patients with 100% accuracy.

METHODS

We reviewed the current literature to examine the role of non-invasive and minimally invasive techniques for staging regional lymph nodes in penile cancer with particular reference to clinically impalpable disease.

RESULTS

Cross-sectional imaging (un-enhanced CT and MRI) modalities have a role in the assessment of patients with palpable inguinal basins and in locating distant metastases, but are unreliable in staging impalpable regional lymph nodes. The spatial resolution of lymphotropic nanoparticle enhanced MRI (LNMRI) and positron emission tomography (PET)/CT are limited to several millimetres and so these modalities cannot reliably detect micro-metastases (<2 mm). Ultrasound (US) and fine-needle aspiration cytology (FNAC) are indicated in staging palpable inguinal basins but are unreliable in isolation in the assessment of impalpable lymph nodes. They are, however, useful as an adjunct to dynamic sentinel lymph node biopsy (DSLNB) in lowering false-negative rates.

CONCLUSIONS

While we await staging modalities that can equal the results of DSLNB with fewer disadvantages, histological staging in the form of DSLNB remains the best minimally invasive staging modality we can offer at risk patients presenting with clinically node negative groins.