Review of in situ and invasive penile squamous cell carcinoma and associated non-neoplastic dermatological conditions

Machine learning-based overall and cancer-specific survival prediction of M0 penile squamous cell carcinoma：A population-based retrospective study

Background

Penile cancer is a rare tumor and few studies have focused on the prognosis of M0 penile squamous cell carcinoma (PSCC). This retrospective study aimed to identify independent prognostic factors and construct predictive models for the overall survival (OS) and cancer-specific survival (CSS) of patients with M0 PSCC.

Methods

Data was extracted from the Surveillance, Epidemiology, and End Results database for patients diagnosed with malignant penile cancer. Eligible patients with M0 PSCC were selected according to predetermined inclusion and exclusion criteria. These patients were then divided into a training set, a validation set, and a test set. Univariate and multivariate COX regression analyses were initially performed to identify independent prognostic factors for OS and CSS in M0 PSCC patients. Subsequently, traditional and machine learning prognostic models, including random survival forest (RSF), COX, gradient boosting, and component-wise gradient boosting modelling, were constructed using the scikit-survival framework. The performance of each model was assessed by calculating time-dependent area under curve (AUC), C-index, and integrated Brier score (IBS), ultimately identifying the model with the highest performance. Finally, the Shapley additive explanation (SHAP) value, feature importance, and cumulative rates analyses were used to further estimate the selected model.

Results

A total of 2, 446 patients were included in our study. Cox regression analyses demonstrated that age, N stage, and tumor size were predictors of OS, while the N stage, tumor size, surgery, and residential area were predictors of CSS. The RSF and COX models had a higher time-independent AUC and C-index, and lower IBS value than other models in OS and CSS prediction. Feature importance analysis revealed the N stage as a common significant feature for predicting M0 PSCC patients' survival. The SHAP and cumulative rate analyses demonstrated that the selected models can effectively evaluate the prognosis of M0 PSCC patients.

Conclusion

In M0 PSCC patients, age, N stage, and tumor size were predictors of OS. In addition, the N stage, tumor size, surgery, and residential area were predictors of CSS. The machine learning-based RSF and COX models effectively predicted the prognosis of M0 PSCC patients.

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.

The prognostic value of lymph node ratio in comparison to positive lymph node count in penile squamous cell carcinoma

PURPOSE

Penile cancer is a rare male neoplasm with a wide variation in its global incidence. In this study, the prognostic value of lymph node ratio (LNR) was compared to that of positive lymph node count (PLNC) in penile squamous cell carcinoma.

METHODS

A total of 249 patients with penile squamous cell carcinoma were enrolled from The Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2015. The X-tile program was used to calculate the optimal cut-off values of LNR and PLNC that discriminate survival. We used the χ² or the Fisher exact probability test to assess the association between clinical-pathological characteristics and LNR or PLNC. Univariate and multivariate Cox regression analyses were performed to identify independent prognostic factors for survival. Spearman correlation analysis was used to determine the correlation between LNR and PLNC.

RESULTS

We found that patients with high LNR tended to have advanced N stage, the 7th AJCC stage, and higher pathological grade, while patients with high PLNC had advanced N stage and the 7th AJCC stage. Univariate Cox regression analysis revealed that the N stage, M stage, the 7th AJCC stage, lymph-vascular invasion, LNR, and PLNC were significantly associated with prognosis. Multivariate Cox regression analysis demonstrated that LNR rather than PLNC was an independent prognostic factor for cancer-specific survival. Subgroup analysis of node-positive patients showed that LNR was associated with CSS, while PLNC was not.

CONCLUSION

LNR was a better predictor for long-term prognosis than PLNC in patients with penile squamous cell carcinoma.

Erectile function after partial penectomy for penile cancer

PURPOSE

To evaluate the erectile function in patients who underwent partial penectomy and identify factors associated with penile functional status.

MATERIALS AND METHODS

We identified patients who underwent partial penectomy due to penile cancer between 2009 and 2014. Clinical and pathological characteristics included patient age at the time of diagnosis, obesity, hypertension, dyslipidemia, diabetes, smoking, metabolic syndrome, Eastern Cooperative Oncology Group (ECOG) status, penile shaft length, tumor size, primary tumor stage (pT), clinical nodal status, and local recurrence. Erectile function was assessed prospectively with the International Index of Erectile Function (IIEF-5) at least 3 months after partial penectomy.

RESULTS

A total of 81 patients met analysis criteria. At the diagnosis, the median age was 62 years (range from 30 to 88). Median follow-up was 17 months (IQR 7-36). Of total patients, 37 (45%) had T2 or higher disease. Clinically positive nodes were present in 16 (20%) patients and seven (8.6%) developed local recurrence. Fifty patients (62%) had erectile dysfunction (ED) after partial penectomy, 30% had moderate or severe erectile dysfunction scores. Patients with ED versus without ED were similar in baseline characteristics except for age, penile shaft length, and presence of inguinal adenopathy (p <0.05). Multivariate analysis using logistic regression confirmed that older patients, shorter penile shaft length, and clinically positive lymph node were significantly associated with ED.

CONCLUSION

Partial penectomy due to penile cancer provides adequate local control of the disease, however, proper counselling is important especially in relation to ED consequences. Preservation of penile length yields to more optimal erectile recovery.

Current management and future perspectives of penile cancer: An updated review

Penile cancer (PeCa) is a rare disease worldwide, accounting for less than one percent of all malignancies in men. It usually presents as a painless ulcer or lump on the head of the penis. Squamous cell carcinoma represents the most common histological subtype of PeCa, with pathogenesis intimately linked to chronic Human Papilloma Virus (HPV) infection. Surgery is the cornerstone for the treatment of primary PeCa with potential mutilating outcome depending on the nodal extension of the disease. However, in case of extensive lymph node involvement, multidisciplinary treatment including perioperative chemotherapy and inclusion in clinical trial should be considered. To date, advanced or metastatic disease still have poor prognosis and are a therapeutic challenge with limited options, highlighting the need of new treatments and further investigations. Growing efforts to identify molecular alterations, understand the role of HPV and characterize immune contexture have expanded over the past years, providing further perspectives in prognostication, predictive biomarkers and therapeutic intervention. In this review, we provide an updated overview of current management of PeCa focusing on perioperative strategy. We discuss about new insights of the biology of PeCa and comment future directions in the field.

Recent advances in understanding and managing Lichen Sclerosus

Lichen sclerosus (LS), or balanitis xerotica obliterans as it was previously known, is a chronic inflammatory lymphocyte-mediated scarring dermatosis that often affects the preputial skin and glans, leading to phimosis and urethral strictures if left untreated. We present a narrative review of the literature assessing its aetiology and pathogenesis and discuss its links to penile cancer and its medical and surgical management. Possible hypotheses for the development of LS include chronic exposure to trapped urine, leading to changes in the epithelial structure. This is supported by the fact that circumcision is often curative in the early stages of the disease. Although circumcision can be curative, the use of topical steroids is typically the first-line treatment and may preserve the foreskin and forgo the need for circumcision altogether. Patients should be made aware of a possible association with penile cancer. Although the majority of cases can be treated by medical therapy and circumcision, a significant number of patients may also require penile reconstructive procedures.

Management of clinically node-negative groin in patients with penile cancer

Malignant penile neoplasms are commonly squamous etiology, with the inguinal nodes being the first echelon of spread. The disease spreads to the pelvic lymph nodes only after metastases to the groin nodes, and this is the most important prognostic factor in penile carcinoma. While treatment of penile carcinoma with proven metastases to the inguinal lymph nodes mandates ilioinguinal lymph node dissection, the treatment of patients with impalpable nodes is more controversial. Overtreatment leads to excessive treatment-related morbidity in these patients, while a wait-and-see policy runs the risk of patients presenting with inguinal and distant metastases, which would have been curable at presentation. Unfortunately, no single imaging modality has been proved to be convincingly superior in the staging, and hence, management of the clinically negative groin has been subject to debate. While some high volume centers have promoted the use of dynamic sentinel lymph node biopsy, others advocate the use of the modified inguinal lymph node template to stage the groin adequately. Newer techniques such as video endoscopic inguinal lymph node dissection have been introduced as an alternative to the original radical inguinal lymphadenectomy to reduce morbidity.

Human papillomavirus (HPV) genotype distribution in penile carcinoma: Association with clinic pathological factors

Background

Penile carcinoma (PC) is a rare, highly mutilating disease, common in developing countries. The evolution of penile cancer includes at least two independent carcinogenic pathways, related or unrelated to HPV infection.

Objectives

To estimate the prevalence, identify HPV genotypes, and correlate with clinicopathological data on penile cancer.

Methods

A retrospective cohort study involving 183 patients with PC undergoing treatment in a referral hospital in Goiânia, Goiás, in Midwestern Brazil, from 2003 to 2015. Samples containing paraffin embedded tumor fragments were subjected to detection and genotyping by INNO-LiPA HPV. The clinicopathological variables were subjected to analysis with respect to HPV positivity and used prevalence ratio (PR), adjusted prevalence ratio (PRa) and 95% confidence interval (CI) as statistical measures.

Results

The prevalence of HPV DNA in PC was 30.6% (95% CI: 24.4 to 37.6), high-risk HPV 24.9% (95% CI: 18.9 to 31.3), and 62.5% were HPV 16. There was a statistical association between the endpoints HPV infection and HPV high risk, and the variable tumor grade II-III (p = 0.025) (p = 0.040), respectively. There was no statistical difference in disease specific survival at 10 years between the HPV positive and negative patients (p = 0.143), and high and low risk HPV (p = 0.325).

Conclusions

The prevalence of HPV infection was 30.6%, and 80.3% of the genotypes were identified as preventable by anti-HPV quadrivalent or nonavalent vaccine. HPV infections and high-risk HPV were not associated with penile carcinoma prognosis in this study.

Beyond chemotherapy for advanced disease-the role of EGFR and PD-1 inhibitors

Penile squamous cell carcinoma (SCC) is a rare malignancy with limited treatment options when the tumor is unresectable and/or chemorefractory. Triplet systemic chemotherapy regimens including taxane and cisplatin are recommended, but the response duration can be short and the treatment-related toxicity high. Only a small proportion of patients survive 1 year or longer with the current standard treatment paradigm. Beyond chemotherapy, the use of novel targeted agents, either alone or in combination with traditional chemotherapeutic agents, has appeared to have promising efficacy in patients with platinum-refractory penile cancer. The frequent overexpression of PD-L1 in advanced penile SCC indicates the potential efficacy of PD-1 inhibitors. Upcoming clinical trials using the immune check-point inhibitors may provide exciting landscape and change the paradigm for patients in the future.

Contemporary management of patients with penile cancer and lymph node metastasis

Penile cancer is a rare disease that causes considerable physical and psychological patient morbidity, especially at advanced stages. Patients with low-stage nodal metastasis can achieve durable survival with surgery alone, but those with extensive locoregional metastasis have overall low survival. Contemporary management strategies for lymph node involvement in penile cancer aim to minimize the morbidity associated with traditional radical inguinal lymphadenectomy through appropriate risk stratification while optimizing oncological outcomes. Modified (or superficial) inguinal lymph node dissection and dynamic sentinel lymph node biopsy are diagnostic modalities that have been recommended in patients with high-risk primary penile tumours and nonpalpable inguinal lymph nodes. In addition, advances in minimally invasive and robot-assisted lymphadenectomy techniques are being investigated in patients with penile cancer and might further decrease lymphadenectomy-related adverse effects. The management of patients with advanced disease has evolved to include multimodal treatment with systemic chemotherapy before surgical intervention and can include adjuvant chemotherapy after pelvic lymphadenectomy. The role of radiotherapy in the neoadjuvant or adjuvant setting remains largely unclear, owing to a lack of high-level evidence of possible benefits. New targeted therapies have shown efficacy in squamous cell carcinomas of other sites and might also prove effective in patients with penile cancer.