External validation of nomogram to predict inguinal lymph node metastasis in patients with penile cancer and clinically negative lymph nodes

Analysis of the related risk factors of inguinal lymph node metastasis in patients with penile cancer: A cross-sectional study

Purpose:

To determine independent predictors of inguinal lymph node (ILN) metastasis in patients with penile cancer.

Patients and methods:

We retrospectively analyzed all patients with penile cancer who underwent surgery at our medical center in the last ten years (n=157). Using univariate and multivariate logistic-regression models, we assessed associations with age, medical-history, phimosis, onset-time, number and maximum diameter of involved ILNs measured by imaging, pathological T stage, degree of tumor differentiation and/or cornification, lymphatic vascular infiltration (LVI), nerve infiltration, and ILN metastases. Interaction and stratified analyses were used to assess age, phimosis, onset time, number of ILNs, cornification, and nerve infiltration.

Results:

A total of 110 patients were included in the study. Multiple logistic regression analysis showed that the following factors were significantly correlated with ILN metastasis: maximum diameter of enlarged ILNs, T stage, pathological differentiation, and LVI. Among patients with a maximum ILN diameter ≥1.5cm, 50% had lymph node metastasis whereas 30.6% patients with a maximum ILN diameter <1.5cm showed LNM. Among 44 patients with stage Ta/T1, 10 showed ILN metastases, while 47.0% patients with stage T2 showed ILN metastases. Among 40 patients with highly differentiated penile-cancer, eight showed ILN metastasis, while 47.1% patients with low-to-middle differentiation showed ILN metastases. The rate of LNM was 33.3% in the LVI-free group and 64.3% in the LVI group.

Conclusion:

Our single-center results suggested that maximum ILN diameter, pathological T stage, pathological differentiation, and LVI were independent risk factors for ILN metastases.

Use of flaps in inguinal lymphadenectomy in metastatic penile cancer

PURPOSE

Reviewing surgical procedures using fasciocutaneous and myocutaneous flaps for inguinal reconstruction after lymphadenectomy in metastatic penile cancer.

MATERIAL AND METHODS

We reviewed the current literature of the Pubmed database according to PRISMA guidelines. The search terms used were "advanced penile cancer", "groin reconstruction", and "inguinal reconstruction", both alone and in combination. The bibliographic references used in the selected articles were also analyzed to include recent articles into our research.

RESULTS

A total of 54 studies were included in this review. About one third of penile cancers are diagnosed with locally advanced disease, often presenting with large lymph node involvement. Defects in the inguinal region resulting from the treatment of metastatic penile cancer are challenging for the surgeon and cause high patient morbidity, rendering primary closure unfeasible. Several fasciocutaneous and myocutaneous flaps of the abdomen and thigh can be used for the reconstruction of the inguinal region, transferring tissue to the affected area, and enabling tensionless closure.

CONCLUSIONS

The reconstruction of defects in the inguinal region with the aid of flaps allows for faster postoperative recovery and reduces the risk of complications. Thus, the patient will be able to undergo potential necessary adjuvant treatments sooner.

Lymph Node Dissections for T3T4 Stage Penile Cancer Patients Without Preoperatively Detectable Lymph Node Metastasis Bring More Survival Benefits: A Propensity Matching Analysis

Background and Aims

The current guidelines for the treatment of penile cancer patients with clinically non-invasive normal inguinal lymph nodes are still broad, so the purpose of this study is to determine which patients are suitable for lymph node dissection (LND).

Methods

Histologically confirmed penile cancer patients (primary site labeled as C60.9-Penis) from 2004 to 2016 in the Surveillance, Epidemiology, and Results database were included in this analysis. Univariate and multivariate Cox regression analyses were applied to determine an overall estimate of LND on overall survival and cancer-specific survival. A 1:1 propensity matching analysis (PSM) was applied to enroll balanced baseline cohort, and further Kaplan-Meier (KM) survival analysis was used to get more reliable results.

Results

Out of 4,458 histologically confirmed penile cancer patients with complete follow-up information, 1,052 patients were finally enrolled in this analysis. Age, pathological grade, T stage, and LND were identified as significant predictors for overall survival (OS) in the univariate Cox analysis. In the multivariate Cox regression, age, pathological grade, T stage, and LND were found significant. The same results were also found in the univariate and multivariate Cox regression analyses for cancer-specific survival (CSS). After the successful PSM, further KM analysis revealed that LND could bring significant OS and CSS benefits for T3T4 patients without lymph node metastasis.

Conclusion

Lymph node dissection may bring survival benefits for penile cancer patients without preoperatively detectable lymph node metastasis, especially for T3T4 stage patients. Further randomized control trial is needed.

Predict Lymph Node Metastasis in Penile Cancer Using Clinicopathological Factors and Nomograms

Objective

To investigate the predictive factors of lymph node metastasis (LNM) and evaluate the usefulness of prediction nomograms.

Methods

This study included 300 patients diagnosed with penile squamous cell carcinoma at West China Hospital (WCH) of Sichuan University (Chengdu, China) and 412 cases acquired from the Surveillance, Epidemiology, and End Results (SEER) program. Logistic regression analysis was performed on these cohorts to investigate the predictive factors of LNM. We evaluated a recently developed prediction nomogram for LNM, which was established based on the National Cancer Database (NCDB). Moreover, we developed a novel nomogram using cases from the WCH for the prediction of lymphatic metastasis.

Results

Logistic analysis identified that younger age at diagnosis, invasion of the penis body, poorer pT stage, cN stage, nuclear grade and the presence of lymph vascular invasion (LVI) were significantly correlated with LNM in WCH cases; however, only race, poorer T stage and cN stage were significantly associated with LNM among the cases from the SEER. Multivariate analysis demonstrated that younger age, poorer T stage, cN stage and nuclear grade were independent predictors of LNM. Receiver operating characteristic curve analysis of WCH cases showed that the tumor T stage 8th edition has better area under the curve than 7th stage (0.672 vs 0.636, respectively). Moreover, well AUC was seen in external validation of NCDB nomogram in WCH cohorts and SEER series (0.833 vs 0.795). The new nomogram included the aforementioned independent predictors and the bootstrap-corrected concordance was 0.876.

Conclusion

Younger diagnose age, poorer pT stage, cN stage, nuclear grade and LVI were the most important predictors of LNM in patients with penile cancer. 8th T stage performed better than 7th version in predicting LNM. NCDB nomogram has some application values in both WCH and SEER cases, and our novel model further improved the predictive accuracy.

The role of primary inguinal surgical debulking for locally advanced penile cancer followed by reconstruction with myocutaneous flap

PURPOSE

To evaluate surgical complications and oncological outcomes of patients submitted to primary radical inguinal surgical debulking (PRISD) and myocutaneous pediculate flap reconstruction (MPFR) for locally advanced penile cancer (PC).

MATERIALS AND METHODS

Forty-two patients with ulcerated and/or fixed bulky inguinal masses underwent unilateral or bilateral PRISD with MPFR. Tensor fascia lata flap (TFL) was the standard of care for all patients. Additional use of the gracilis flap (GF) was carried out when necessary. Contra-lateral radical inguinal lymphadenectomy (RIL) was conduced when PRISD was performed unilaterally. Surgical complications were analyzed and stratified into minor and major according to the Bevan-Thomas classification. Adjunctive treatments were assessed and oncological outcomes analyzed.

RESULTS

Of the 42 patients evaluated, 10 (23.8%) underwent bilateral PRISD and 32 (76.2%) unilateral PRISD with contra-lateral RIL, totaling 84 lymphadenectomies. A total of 62 MPFRs were performed, 52 with TFL and 10 with GF. A total of 53 complications were identified, 49 related to PRISD with MPFR and 4 to RIL. Adjuvant chemotherapy was carried out in 16 patients. Median follow-up was 10.8 months with a median overall survival (OS) of 14.0 months against 6.0 months (p=0.006) for patients submitted to PRISD with adjuvant chemotherapy in relation to surgery alone.

CONCLUSIONS

PRISD alone for advanced loco-regional PC is unlikely to promote long-term survival, although it can lead to temporary local control of the disease. Despite the feasibility of the procedure, it is related to high incidence of complications. Surgical treatment with adjuvant chemotherapy is associated with improved OS.

Prognostic predictors of lymph node metastasis in penile cancer: a systematic review

PURPOSE

Squamous cell carcinoma (SCC) of the penis is a rare disease in developed countries but is associated with significant morbidity and mortality. A crucial prognostic factor is the presence of inguinal lymph node metastases (ILNM) at the time of diagnosis. At least 25% of cases have micrometastases at the time of diagnosis. Therefore, we performed a literature review of studies evaluating factors, both clinical and pathological, predictive of lymph node metastases in penile SCC.

MATERIALS AND METHODS

Studies were identified using PubMed and search terms included the following: penile cancer, penile tumor, penile neoplasm, penile squamous cell carcinoma, inguinal lymph node metastasis, lymph node metastases, nodal metastasis, inguinal node metastasis, inguinal lymph node involvement, predictors, and predictive factor. The number of patients and predictive factors were identified for each study based on OR, HR, or RR in multivariate analyses, as well as their respective significance values. These were compiled to generate a single body of evidence supportive of factors predictive of ILNM in penile SCC.

RESULTS

We identified 31 studies, both original articles and meta-analyses, which identified factors predictive of metastases in penile SCC. The following clinical factors were predictive of ILNM in penile SCC: lymphovascular invasion (LVI), increased grade, increased stage (both clinical and pathological), infiltrative and reticular invasion, increased depth of invasion, perineural invasion, and younger patient age at diagnosis. Biochemically, overexpression of p53, SOD2, Ki-67, and ID1 were associated with spread of SCC to inguinal lymph nodes. Diffuse PD-L1 expression, increased SCC-Ag expression, increased NLR, and CRP >20 were also associated with increased ILNM.

CONCLUSIONS

A multitude of factors are associated with metastasis of SCC of the penis to inguinal lymph nodes, which is associated with poor clinical outcomes. The above factors, most strongly LVI, grade, and node positivity, may be considered when constructing a nomogram to risk-stratify patients and determine eligibility for prophylactic inguinal lymphadenectomy.

Impact of Examined Lymph Node Count and Lymph Node Density on Overall Survival of Penile Cancer

BACKGROUND

Few studies have explored the optimal examined lymph node count and lymph node density cutoff values that could be used to predict the survival of patients with penile cancer. We further clarify the prognostic value of lymph node density and examined lymph node count in penile cancer.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was explored to recruit penile cancer patients from 2010 to 2015. A retrospective analysis of penile cancer patients' data from the First Affiliated Hospital of Anhui Medical University was performed for verification (2006-2016). The cutoff values of examined lymph node count and lymph node density were performed according to the ROC curve. Kaplan-Meier survival analysis was used to compare survival differences among different groups. Univariate and multivariate Cox proportional hazard regression analyses were used to determine the significant variables. On the basis of Cox proportional hazards regression model, a nomogram was established and validated by calibration plot diagrams and concordance index (C-index).

RESULTS

A total of 528 patients in the Surveillance, Epidemiology, and End Results cohort and 156 patients in the Chinese cohort were included in this study. Using the ROC curve, we found that the recommended cutoff values of ELN and LND were 13 and 9.3%, respectively (P <0.001). Kaplan-Meier curves suggested the significant differences of overall survival among different examined lymph nodes and lymph node density. Multivariate analysis indicated ELN and LND were independent prognostic factor for OS of penile cancer patients. Nomogram showed the contribution of ELN and LND to predicting OS was large. The C-index at 3-, and 5-year were 0.744 for overall survival (95% CI 0.711-0.777).

CONCLUSIONS

The more lymph nodes examined, the lower the density of lymph nodes, and the higher the long-term survival rate of penile cancer. We recommended 13 examined lymph nodes and lymph node density >9.3% as the cutoff value for evaluating the prognosis of penile cancer patients.

DaPeCa-8: drawing the map of lymphatic drainage in patients with invasive penile cancer - evidence from SPECT/CT and sentinel node surgery

BACKGROUND

Anatomy of the lymphatic drainage guides the extent of inguinal lymph node dissection in penile cancer.

OBJECTIVE

To prospectively assess the lymphatic drainage of penile cancer with single-photon emission computed tomography CT (SPECT-CT) and implications for the extent of inguinal lymph node dissection.

METHODS

We assessed the lymphatic drainage of 62 patients with at least unilateral clinical lymph node-negative (cN0) status with SPECT-CT at our tertiary referral centre. We evaluated 122 cN0 inguinal basins and compared them to the histopathological outcome. The inguinal regions were divided into ten different Daseler zones on SPECT-CT. The surgical team filled in a corresponding scheme at sentinel node biopsy and sent lymph nodes from each Daseler zone individually for histopathological examination.

RESULTS

SPECT-CT successfully visualized lymphatic drainage in 116 of the 122 cN0 inguinal basins (95.1%). The vast majority of sentinel nodes and all metastatic nodes were located in central and superior inguinal zones, including six metastatic nodes in lateral superior zones. Minimal lymphatic drainage was seen to the inferior Daseler zones and no metastatic deposits were located here. No direct pelvic drainage was observed.

CONCLUSIONS

Penile cancer lymphatic drainage is primarily to sentinel in the superior and central zones of Daseler. Colleagues practicing a modified inguinal lymph node dissection as a standard in cN0 patients are encouraged to include all these zones, while the inferior zones can be omitted. This study confirms the absence of lymphatic drainage directly to the pelvic region and supports the practice of omitting pelvic nodes from sentinel node biopsy.