Prognostic factors for occult inguinal lymph node involvement in penile carcinoma and assessment of the high-risk EAU subgroup: a two-institution analysis of 342 clinically node-negative patients.

BACKGROUND: The European Association of Urology (EAU) guidelines advise an elective bilateral lymphadenectomy in clinically node-negative (cN0) patients with high-risk penile carcinoma (≥pT2, G3, or lymphovascular invasion [LVI]). OBJECTIVE: Our aim was to assess prognostic factors for occult metastasis and to determine whether current EAU guidelines accurately stratify patients at high risk. DESIGN, SETTING, AND PARTICIPANTS: Data of 342 cN0 patients with histologically proven invasive penile squamous cell carcinoma who had undergone the current dynamic sentinel node biopsy (DSNB) protocol were analysed. A complete ipsilateral inguinal lymphadenectomy was only done if the sentinel node was tumour positive. MEASUREMENTS: The presence of occult metastasis was established by preoperative ultrasound and tumour-positive fine-needle aspiration cytology, tumour-positive sentinel nodes, and groin metastases during follow-up after a negative DSNB procedure. Median follow-up was 31 mo. RESULTS AND LIMITATIONS: Sixty-eight of 342 patients (20%) and 87 of 684 groins (13%) had occult nodal involvement including 6 patients (2%) with a groin metastasis after negative DSNB. Corpus spongiosum invasion, corpus cavernosum invasion, histologic grade, and LVI were each significant prognosticators for occult metastasis on univariate analysis. On multivariate analysis, grade (odds ratio [OR]: 3.3 for intermediate and 4.9 for poor, respectively) and LVI (OR: 2.2) remained predictive factors. In total, 245 patients (72%) were classified high risk according to EAU guidelines. Among them, the incidence of occult metastasis was 23% (57 of 245). A potential limitation of this study is the lack of external review. CONCLUSIONS: Histologic grade and LVI are independent prognostic factors for occult metastasis in penile carcinoma. Although both predictors are incorporated into the current EAU guidelines, the stratification of patients needing a lymph node dissection is inaccurate. Approximately 77% of high-risk patients (188 of 245) would have had a negative bilateral inguinal lymphadenectomy. For the time being, DSNB is considered a more suitable staging method than EAU risk stratification for an accurate determination of patients who require lymph node dissection.

Evaluation of current TNM classification of penile carcinoma.

PURPOSE: The TNM classification is the most common tool for staging malignancies. The current classification for penile carcinoma has been unchanged since 1987. There are several shortcomings to this classification. Accurate clinical staging can be troublesome because several categories are defined by anatomical structures that cannot readily be identified by physical examination or imaging. A second drawback is substantial variability with respect to survival in certain T and N categories. We analyzed the prognostic value of the TNM classification in patients with penile carcinoma treated at our institute. We propose modifications to improve prognostic stratification and facilitate clinical staging. MATERIALS AND METHODS: The records of 513 patients treated between 1956 and 2006 were analyzed. All tumors were staged according to the most recent classification. We calculated disease specific survival in the different T and N categories. Survival in the different categories was compared using Kaplan-Meier analysis and the log rank test. RESULTS: Five-year disease specific survival in the entire group was 80.5% at a median followup of 58.7 months. There was no significant difference in survival between T2 and T3 tumors (p = 0.57). Furthermore, no significant survival difference was found between N1 and N2 categories (p = 0.18). Using a modified classification a significant difference in survival was found among all T and N categories. CONCLUSIONS: The current TNM classification for penile carcinoma does not adequately differentiate in terms of survival among several T and N categories. With some modifications prognostic stratification improves and clinical staging is facilitated.

Pelvic lymph node dissection for penile carcinoma: extent of inguinal lymph node involvement as an indicator for pelvic lymph node involvement and survival.

PURPOSE: We identified pathological parameters of inguinal lymph node involvement with the aim of predicting pelvic lymph node involvement and survival. MATERIALS AND METHODS: A total of 308 patients with penile carcinoma and adequate followup were included in this study. The outcome of 102 patients who underwent lymphadenectomy for lymph node metastases was analyzed further. Histopathological characteristics of the regional lymph nodes were reviewed including unilateral or bilateral involvement, the number of involved nodes, pathological tumor grade of the involved nodes, and the presence of extracapsular growth. RESULTS: Tumor grade of the involved inguinal lymph nodes (OR 6.0, 95% CI 1.2-30.3) and the number of involved nodes (2 or less vs more than 2) (OR 12.1, 95% CI 3.0-48.1) were independent prognostic factors for pelvic lymph node involvement. Extracapsular growth (OR 2.3, 95% CI 1.1-4.8), bilateral inguinal involvement OR 3.4, 95% CI 1.2-9.4) and pelvic lymph node involvement (OR 3.1, 95% CI 1.4-6.6) were independent prognostic factors for disease specific survival. CONCLUSIONS: Patients with only 1 or 2 inguinal lymph nodes involved without extracapsular growth and no poorly differentiated tumor within these nodes are at low risk of pelvic lymph node involvement and have a good prognosis with a 5-year survival rate of approximately 90%. Pelvic lymph node dissection seems to be unnecessary in these cases.

Presence of high-risk human papillomavirus DNA in penile carcinoma predicts favorable outcome in survival.

There is evidence that a subset of penile carcinomas is caused by infection with high-risk human papillomavirus (HPV). However, extensive studies on the possible influence of HPV infection on clinical outcome of penile cancer are lacking. This investigation is aimed to examine the prevalence of high-risk HPV in a large series of penile squamous-cell carcinomas (SCCs) and to determine the relationship between HPV and survival. Formalin-fixed, paraffin-embedded tumor specimens of 171 patients with penile carcinoma were tested for high-risk HPV DNA presence by GP5+/6+-PCR. The clinical course of the patients and the histopathological characteristics of the primary tumors were reviewed. High-risk HPV DNA was detected in 29% of the tumors, with HPV 16 being the predominant type, accounting for 76% of high-risk HPV containing SCCs. Disease-specific 5-year survival in the high-risk HPV-negative group and high-risk HPV-positive group was 78% and 93%, respectively (log rank test p = 0.03). In multivariate analysis, the HPV status was an independent predictor for disease-specific mortality (p = 0.01) with a hazard ratio of 0.14 (95% CI: 0.03-0.63). Our results indicate that the presence of high-risk HPV (29%) confers a survival advantage in patients with penile carcinoma.

Immunogenicity, including vitiligo, and feasibility of vaccination with autologous GM-CSF-transduced tumor cells in metastatic melanoma patients.

PURPOSE: To determine the feasibility, toxicity, and immunologic effects of vaccination with autologous tumor cells retrovirally transduced with the GM-CSF gene, we performed a phase I/II vaccination study in stage IV metastatic melanoma patients. PATIENTS AND METHODS: Sixty-four patients were randomly assigned to receive three vaccinations of high-dose or low-dose tumor cells at 3-week intervals. Tumor cell vaccine preparation succeeded for 56 patients (88%), but because of progressive disease, the well-tolerated vaccination was completed in only 28 patients. We analyzed the priming of T cells against melanoma antigens, MART-1, tyrosinase, gp100, MAGE-A1, and MAGE-A3 using human leukocyte antigen/peptide tetramers and functional assays. RESULTS: The high-dose vaccination induced the infiltration of T cells into the tumor tissue. Three of 14 patients receiving the high-dose vaccine showed an increase in MART-1- or gp100-specific T cells in the peripheral blood during vaccination. Six patients experienced disease-free survival for more than 5 years, and two of these patients developed vitiligo at multiple sites after vaccination. MART-1- and gp100-specific T cells were found infiltrating in vitiligo skin. Upon vaccination, the T cells acquired an effector phenotype and produced interferon-gamma on specific antigenic stimulation. CONCLUSION: We conclude that vaccination with GM-CSF-transduced autologous tumor cells has limited toxicity and can enhance T-cell activation against melanocyte differentiation antigens, which can lead to vitiligo. Whether the induction of autoimmune vitiligo may prolong disease-free survival of metastatic melanoma patients who are surgically rendered as having no evidence of disease before vaccination is worthy of further investigation.

On the role of melanoma-specific CD8+ T-cell immunity in disease progression of advanced-stage melanoma patients.

Cytotoxic T-cell immunity directed against melanosomal differentiation antigens is arguably the best-studied and most prevalent form of tumor-specific T-cell immunity in humans. Despite this, the role of T-cell responses directed against melanosomal antigens in disease progression has not been elucidated. To address this issue, we have related the presence of circulating melanoma-specific T cells with disease progression and survival in a large cohort of patients with advanced-stage melanoma who had not received prior treatment. In 42 (68%) of 62 patients, melanoma-specific T cells were detected, sometimes in surprisingly large numbers. Disease progression during treatment was more frequent in patients with circulating melanoma-specific T cells, and mean survival of patients with circulating melanoma-specific T cells was equal to the survival of patients without melanoma-specific T cells. These data suggest that the induction of melanosomal differentiation antigen-specific T-cell reactivity in advanced stage melanoma is a late event most likely due to antigen load and spreading and is not accompanied by a clinically significant antitumor effect. These melanoma-specific T cells may be functionally distinct from T cells raised during spontaneous regression or up vaccination.

Evidence for at least three alternative mechanisms targeting the p16INK4A/cyclin D/Rb pathway in penile carcinoma, one of which is mediated by high-risk human papillomavirus.

A comprehensive analysis of 53 penile carcinomas was performed to determine which mechanisms might be involved in the disruption of the p16(INK4A)/cyclin D/Rb pathway. To that end, human papillomavirus (HPV) presence, p16(INK4A) expression and promoter methylation, and expression of the BMI-1 polycomb gene product were studied. Sixteen (30%) of the carcinomas were found to harbour high-risk HPV DNA, 15 of which contained HPV 16. HPV 16 E6/E7 oncogene transcripts were detected in 13 (87%) of the carcinomas that contained HPV 16. Strong immunostaining for p16(INK4A) was significantly more frequent in carcinomas that contained high-risk HPV DNA (p < 0.001) and amongst those with HPV 16 DNA, it was more frequent in lesions in which E6/E7 transcripts were detectable (p = 0.029). This supports an active role for HPV E7 in interfering with the p16(INK4A)/cyclin D/Rb pathway. Methylation of the p16(INK4A) promoter or overexpression of the BMI-1 polycomb gene product may provide alternative modes of interference with this pathway. These phenomena were mutually exclusive and found in the absence of HPV in 15% and 10% of the penile carcinomas, respectively. These data indicate that there are at least three plausible mechanisms by which the p16(INK4A)/cyclin D/Rb pathway can become disrupted during penile carcinogenesis.