Incidence and risk factor analysis of complications after sentinel node biopsy for penile cancer

[68Ga]Ga-FAPI-46 PET/CT for penile cancer - a feasibility study

PURPOSE

Penile cancer is a rare entity and has a good prognosis in localized stage. Delayed surgical treatment of lymphatic disease is associated with poor overall survival but conventional imaging cannot detect occult lymph node metastasis sufficiently. Imaging cancer related fibroblasts has shown promising results as non-invasive staging tool in various tumor entities but has not yet been evaluated in penile cancer.

METHODS

In this single-center pilot study, patients planned for surgical treatment for penile cancer underwent preoperatively [68Ga]Ga-FAPI-46 PET/CT. Post-operative histopathology was compared to [68Ga]Ga-FAPI-46 PET/CT results.

RESULTS

From January 2022 to June 2022, a total number 11 patients with histopathologically proven penile cancer underwent surgery and received [68Ga]Ga-FAPI-46 PET/CT prior therapy. 8 primary tumor sites and 4 lymph node regions were analyzed. FAPI uptake was increased on primary tumor site (SUVmax 16.2 (9.1 - 25.8)). Histopathological proven lymph node regions showed highly increased FAPI uptakes (SUVmax 17.9 (16.4 - 23.5) on [68Ga]Ga-FAPI-46 PET/CT.

CONCLUSION

In this first pilot cohort, there were no false-positive FAPI uptake which might allow the detection of occult lymph node metastasis by [68Ga]Ga-FAPI-46 PET/CT and might consequently lead to omitting lymph node regions during surgery that had no increased FAPI uptake pre-operatively.

Minimally Invasive Management of Inguinal Lymph Nodes in Penile Cancer: Recent Progress and Remaining Challenges

The diagnosis of occult inguinal lymph node metastasis in clinically node-negative invasive penile squamous cell carcinoma (PSCC) has remained a challenge, with substantial perioperative complications. The recent refinements in the technique of dynamic sentinel lymph node biopsy (DSLNB) demonstrated high diagnostic accuracy with considerably lower morbidity compared to conventional open modified/superficial inguinal lymph node dissection (ILND). Although DSLNB, if available, has been endorsed as the preferred method for nodal staging in patients with invasive PSCC and no palpable inguinal lymphadenopathy in the recent penile cancer guidelines, its utilization has been quite limited so far. Laparoscopic and robotic-assisted ILND have emerged as alternatives for nodal staging in this patient population and are shown to improve the rate of wound infections and postoperative pain. For management of nodal metastasis in patients with clinically palpable inguinal lymph nodes, minimally invasive ILND has shown promising results as well. Nonetheless, given the rarity of PSCC and the absence of prospective studies and clinical trials, nodal staging and treatment of nodal metastasis in clinical practice will likely continue to vary across the medical centers in the following years. In this review, we first summarize the evolution of DSLNB and minimally invasive ILND and discuss the advantages and drawbacks of each management strategy. We further discuss the remaining challenges and future perspectives in the management of inguinal lymph nodes in patients with PSCC.

New EAU/ASCO guideline recommendations on sentinel node biopsy for penile cancer and remaining challenges from a nuclear medicine perspective

INTRODUCTION

The European Association of Urology (EAU) and the American Society of Clinical Oncology (ASCO) recently issued updated guidelines on penile cancer, emphasising dynamic sentinel node biopsy (DSNB) as the preferred method for surgical staging among patients with invasive penile tumours and no palpable inguinal lymphadenopathy. This paper outlines the rationale behind this new recommendation and describes remaining challenges, as well as strategies for promoting DSNB worldwide.

MAIN TEXT

DSNB offers high diagnostic accuracy with the lowest postoperative complications compared to open or minimally invasive inguinal lymph node dissection (ILND), prompting its preference in the new guidelines. Nevertheless, despite its advantages, there are challenges hampering the widespread adoption of DSNB. This includes the false-negative rate associated with DSNB and the potential negative impact on patient outcome. To address this issue, improvements should be made in several areas, including refining the timing and interpretation of the lymphoscintigraphy and the single photon emission computed tomography/computed tomography images. In addition, the quantity of tracer employed and choice of the injection site for the radiopharmaceutical should be optimised. Finally, limiting the removal of nodes without tracer activity during surgery may help minimise complication rates.

CONCLUSION

Over the years, DSNB has evolved significantly, related to the dedicated efforts and innovations in nuclear medicine and subsequent clinical studies validating its efficacy. It is now strongly recommended for surgical staging among selected penile cancer patients. To optimise DSNB further, multidisciplinary collaborative research is required to improve SN identification for better diagnostic accuracy and fewer complications.

The landscape of penile cancer research in Germany and Austria: a survey among professors in academic centers holding chair positions and results of a literature search

BACKGROUND

Research on penile cancer (PeCa) is predominantly conducted in countries with centralized treatment of PeCa-patients. In Germany and Austria (G + A), no state-regulated centralization is established, and no information is available on how PeCa-research is organized.

METHODS

Current research competence in PeCa was assessed by a 36-item questionnaire sent to all chairholders of urological academic centers in G + A. Based on PubMed records, all scientific PeCa-articles of 2012-2022 from G + A were identified. Current research trends were assessed by dividing the literature search into two periods (P1: 2012-2017, P2: 2018-2022). A bibliometric analysis was supplemented.

RESULTS

Response rate of the questionnaire was 75%, a median of 13 (IQR: 9-26) PeCa-patients/center was observed in 2021. Retrospective case series were conducted by 38.9% of participating clinics, while involvement in randomized-controlled trials was stated in 8.3% and in basic/fundamental research in 19.4%. 77.8% declared an interest in future multicenter projects. 205 PeCa-articles were identified [median impact factor: 2.77 (IQR: 0.90-4.37)]. Compared to P1, P2 showed a significant increase in the median annual publication count (29 (IQR: 13-17) vs. 15 (IQR: 19-29), p < 0.001), in multicenter studies (79.1% vs. 63.6%, p = 0.018), and in multinational studies (53% vs. 28.9%, p < 0.001); the proportion of basic/fundamental research articles significantly declined (16.5% vs. 28.9%, p = 0.041). Four of the top-5 institutions publishing PeCa-articles are academic centers. Bibliometric analyses revealed author networks, primary research areas in PeCa, and dominant journals for publications.

CONCLUSIONS

Given the lack of centralization in G + A, this analysis highlights the need for research coordination within multicenter PeCa-projects. The decline in basic/fundamental research should be effectively addressed by the allocation of funded research projects.

The role of radiotherapy in the management of squamous cell cancer of the penis

PURPOSE

To review the evidence for radiotherapy in the management of primary penile cancer, either as brachytherapy or external beam radiation, and the role of external beam radiotherapy in node positive penile cancer.

METHODS

English language literature was reviewed for the past 3 decades. As penile cancer is uncommon in developed nations, high quality evidence to guide management is limited. Single institution reports often span decades during which time staging systems and treatments have evolved, reducing their relevance to current practice. Successful clinical trials require collaboration not only among disciplines but also among multiple institutions and nations.

RESULTS

Radiotherapy is a definitive organ-preserving option for T1-T2 penile cancers. Interstitial brachytherapy is associated with penile preservation in 85% of men at 5 years, maintained in 70% by 10 years. Results of external radiotherapy are not quite as promising but nonetheless 60% of men will have an intact penis at 5 years. Inguino-pelvic external radiotherapy has been reported to increase overall survival when delivered as adjuvant treatment for men with pN3 groin but pN0 pelvic nodes, and improve disease specific survival for those with involved pelvic nodes. InPACT (ECOG-ACRIN_8134) is investigating the role of inguino-pelvic chemo-radiotherapy for men with pN3 inguinal nodes but imaging negative pelvic nodes.

CONCLUSIONS

Radiotherapy has a well-defined role to play in treatment of squamous cell cancers of other sites, such as vulva, anal canal, uterine cervix and head and neck malignancies. Emerging data support the incorporation of radiotherapy into treatment paradigms for penile cancer.

Accuracy of dynamic sentinel lymph node biopsy for inguinal lymph node staging in cN0 penile cancer

BACKGROUND

Penile cancer is characterized by an early lymphatic dissemination. In intermediate and high-risk primary tumors without palpable inguinal lymph nodes, there is a 6-30% risk of micro-metastatic disease. Invasive lymph node staging in these patients is performed using dynamic sentinel lymph node biopsy (DSNB). In this study, the role of DSNB in cN0 penile cancer was studied, evaluating features of sentinel lymph node (SN) visualization and outcome parameters. Patients with penile cancer without inguinal lymph node metastases who were referred for DSNB at our center between January 2015 and May 2021 and had a follow-up period of at least 18 months, were retrospectively included. After injection of 85 ± 20 MBq [^99mTc]Tc-nanocolloid peritumorally, dynamic, static planar and SPECT/CT imaging was performed. Primary endpoints were sensitivity of the diagnostic procedure, disease-free survival and DSNB-related adverse events. Secondary endpoints were SN detection rate, number of SNs and the number of counts of the most active SN.

RESULTS

Seventy-seven penile DSNB procedures in 75 patients (67 ± 11 years) were included. The detection rate of DSNB was 91% and 96% per procedure and groin, respectively. Sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) were 79%, 100%, 97% and 100%, respectively. More SNs were seen on SPECT/CT than on static planar imaging (1.33 vs. 1.17, p = 0.001). The mean counts per SN on static planar imaging was lower compared to SPECT/CT (1343 vs. 5008; p < 0.0001). There was a positive correlation between the total counts of the SN on the static planar image and the SPECT/CT (r = 0.79, p < 0.0001). Only one out of seventy-five patients (1%) experienced DSNB-related adverse events. After 18 months, 58 patients remained disease free (77%), 13 developed local recurrence (17%), and 4 developed lymphatic or distant metastases (5%).

CONCLUSION

DNSB is a safe diagnostic procedure with a good detection rate and in particular high negative predictive value. It can therefore prevent overtreatment of patients with negative inguinal groins on clinical examination and DSNB examination. Finally, DSNB enables an early detection of occult metastases which would not be visualized with standardized imaging modalities.

European Association of Urology-American Society of Clinical Oncology Collaborative Guideline on Penile Cancer: 2023 Update

CONTEXT

Penile cancer is a rare disease but has a significant impact on quality of life. Its incidence is increasing, so it is important to include new and relevant evidence in clinical practice guidelines.

OBJECTIVE

To provide a collaborative guideline that offers worldwide physician and patient guidance for the management of penile cancer.

EVIDENCE ACQUISITION

Comprehensive literature searches were performed for each section topic. In addition, three systematic reviews were conducted. Levels of evidence were assessed, and a strength rating for each recommendation was assigned according to the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) methodology.

EVIDENCE SYNTHESIS

Penile cancer is a rare disease but its global incidence is increasing. Human papillomavirus (HPV) is the main risk factor for penile cancer and pathology should include an assessment of HPV status. The main aim of primary tumour treatment is complete tumour eradication, which has to be balanced against optimal organ preservation without compromising oncological control. Early detection and treatment of lymph node (LN) metastasis is the main determinant of survival. Surgical LN staging with sentinel node biopsy is recommended for patients with a high-risk (≥pT1b) tumour with cN0 status. While (inguinal) LN dissection remains the standard for node-positive disease, multimodal treatment is needed in patients with advanced disease. Owing to a lack of controlled trials and large series, the levels of evidence and grades of recommendation are low in comparison to those for more common diseases.

CONCLUSIONS

This collaborative penile cancer guideline provides updated information on the diagnosis and treatment of penile cancer for use in clinical practice. Organ-preserving surgery should be offered for treatment of the primary tumour when feasible. Adequate and timely LN management remains a challenge, especially in advanced disease stages. Referral to centres of expertise is recommended.

PATIENT SUMMARY

Penile cancer is a rare disease that significantly impacts quality of life. While the disease can be cured in most cases without lymph node involvement, management of advanced disease remains challenging. Many unmet needs and unanswered questions remain, underlining the importance of research collaborations and centralisation of penile cancer services.

Surgical complications following sentinel lymph node biopsy guided by γ-probe and methylene blue in 113 tumour-bearing dogs

Sentinel lymph node biopsy (SLNB) is an accepted veterinary surgical procedure given the impact of early detection of nodal metastases on staging of several canine malignancies. This study aims at reporting the incidence and risk factors for surgical complications of SLNB in tumour-bearing dogs. A total of 113 client-owned dogs that underwent tumour excision and SLNB guided by γ-probing and blue dye were retrospectively enrolled. Recorded variables included: signalment, location and number of extirpated lymphocenters and nodes, time for SLNB, histopathological status of excised nodes. Incidence of SLNB complications was calculated. They were classified as minor and major based on severity and required treatment, and as short-term (0-30 days) and long-term (31-90 days). Univariate analysis with generalized linear model with binomial error estimated the association between variables and incidence of SLNB complications. Significance was set at 5%. Median overall time for SLNB was 25 min. Surgeons excised one node in 38% of dogs and multiple nodes in 62% of cases, belonging to one (62%) or multiple (38%) lymphocenters. Metastases were detected in 45% of nodes. No intraoperative complications occurred. The overall incidence of postoperative complications of SLNB was 21,24%, the majority of which (91.67%) were minor. Only increasing dogs' weight was associated with an increased incidence of SLNB complications (p = .00976). Sentinel lymphadenectomy was associated with a relatively low incidence of complications, most of which were self-limiting. The low morbidity and previously reported impact on staging of SLNB justify its implementation to collect data for prognostic studies.

Sentinel Node Identification with Hybrid Tracer-guided and Conventional Dynamic Sentinel Node Biopsy in Penile Cancer: A Prospective Study in 130 Patients from the Two National Referral Centres in Sweden

BACKGROUND

Studies suggest that a hybrid indocyanine green (ICG)-^99mTc-nanocolloid tracer improves sentinel node (SN) identification compared to conventional dynamic sentinel node biopsy (DSNB).

OBJECTIVE

To investigate hybrid tracer-guided SN identification in a multicentre setting and determine false-negative (FN) and complication rates.

DESIGN, SETTING, AND PARTICIPANTS

A total of 130 patients with penile cancer scheduled for DSNB were prospectively included between February 2016 and December 2017 at two national Swedish referral centres. ICG-^99mTc-nanocolloid hybrid tracer was used in the standard DSNB protocol.

INTERVENTION

SNs were identified intraoperatively using radioguidance, fluorescence imaging, and blue dye.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The number of SNs identified by each tracer and the rates of complications and nodal recurrence during median follow-up of 34 mo were recorded. Differences in proportions between groups were compared using χ² and McNemar's tests.

RESULTS AND LIMITATIONS

Overall, 453 SNs were identified preoperatively via single-photon emission computed tomography/computed tomography. Among the 425 SNs excised, radioguidance, fluorescence, and blue dye identified 414 (97%), 363 (85%), and 349 (82%), respectively. Fluorescence imaging helped to detect six SNs that were negative using the other tracers, two of which were from the same patient and contained metastases. Histopathological examination detected 33 metastatic SNs in 20/130 patients (15%). The FN rate was 12% per groin (95% confidence interval 8-16%).

CONCLUSIONS

Identification of SNs in patients with penile cancer relies mainly on radioguidance, while fluorescence (ICG) and blue dye methods for optical SN identification are comparable. However, the value of fluorescence imaging should be further evaluated in studies with long-term follow-up.

PATIENT SUMMARY

In this study, we investigated addition of a dye called indocyanine green (ICG) for assessment of lymph nodes in patients with cancer of the penis. ICG did not improve the rate of detection of nodes most likely to harbour cancer because of their location in the drainage pathway for lymphatic fluid, but did help in identifying additional metastases.

Lymphovascular and perineural invasion are risk factors for inguinal lymph node metastases in men with T1G2 penile cancer

PURPOSE

To analyse the risk of inguinal lymph node (ILN) metastases in T1G2 penile cancer stratified by lymphovascular invasion (LVI), perineural invasion (PNI) and tumour size.

METHODS

Retrospective study of men with localised T1G2 penile cancer with non-palpable lymph nodes and no local recurrence during follow-up at six European institutional high-volume centres was performed. ILN involvement was defined as cancer detected during ultrasound-guided fine-needle aspiration cytology, core needle biopsy, dynamic sentinel lymph node biopsy, ILN dissection or inguinal recurrence during follow-up. Uni- and multivariable logistic regression analyses were performed.

RESULTS

In the cohort of 554 men with T1G2 penile cancer, from 6 European institutions, ILN metastases were observed in 46/554 men (8%, 95% confidence interval (CI) 6-11%). Men with both, LVI- and PNI- primary cancers had the lowest risk of ILN involvement (6%) whereas men with LVI + or PNI + showed ILN metastases in 22% and 30%. In multivariable regression, men with LVI + or PNI + had higher odds for ILN metastases compared to men with LVI- and PNI- (OR 3.9, 95% CI 1.6-9.0, p value < 0.01) Tumour size was not associated with ILN risk (OR 1.01 95% CI 0.99-1.04, p = 0.17).

CONCLUSION

Approximately, one out of ten men with T1G2 overall and one out of four men with either LVI + or PNI + still have ILN metastases despite being clinically node negative. Therefore, invasive ILN staging should strongly be recommended in T1G2 with LVI + or PNI + but importantly, must be discussed in patients with T1G2 with LVI- or PNI-.