Clear-cell differentiation and lymphatic invasion, but not the revised TNM classification, predict lymph node metastases in pT1 penile cancer: a clinicopathologic study of 76 patients from a low incidence area.

OBJECTIVE: Prediction of lymph node (LN) metastases in penile invasive cancer relies on clinical features and histologic characteristics of the primary tumor. Correct prediction, however, is difficult, as only 50% patients undergoing lymphadenectomies will have LN metastases. In 2009, the tumor, nodes, metastases (TNM) classification for staging of early penile cancers was revised. We tested the predictive accuracy of the revised TNM classification in a low incidence area for penile carcinoma. MATERIALS AND METHODS: The presence of LN metastases in 76 men with pT1 penile cancers was correlated with the 2009 TNM subclassification, which is based on a combined evaluation of tumor grade and lymphatic invasion, but also with individual parameters, such as histologic grade, lymphatic invasion, perineural invasion, invasion depth, growth pattern and human papilloma virus (HPV) status. RESULTS: 76pT1 penile cancers were reclassified into 31pT1a squamous cell carcinomas (SCC) and 45pT1b (41 SCC; 4 clear-cell carcinomas); 12/22 men (55%; 8 SCC, 4 clear-cell carcinomas) undergoing lymphadenectomy for enlarged inguinal lymph nodes had metastases, 54 patients without enlarged LN and lymphadenectomies had no LN metastases during follow-up of median 47 months. Statistically, clear cell differentiation of the primary carcinoma was highly associated with metastases (100% clear-cell carcinomas vs. 11% SCC) and poor survival (50% vs. 5.5%). Among conventional SCC, only lymphatic invasion showed a highly significant association with metastases with 100% specificity. The 2009 TNM classification, tumor grade alone, perineural invasion, growth pattern, invasion depth or HPV status could not predict LN status. Lymphadenectomy for enlarged LN resulted in 100% sensitivity and 42% predictive probability for identifying metastases and a 16% false positive rate. Statistically, survival correlated significantly with clear-cell differentiation and with lymphatic invasion in both clear-cell carcinomas and conventional SCC. CONCLUSIONS: Penile clear-cell carcinomas are more aggressive cancers than SCC. Our observation suggests a benefit of a prophylactic lymphadenectomy for patients with clear-cell carcinomas. Among conventional SCC, only lymphatic invasion predicted LN metastases. Neither tumor grade alone nor perineural invasion, growth pattern, depth of invasion, and subgrouping according to the revised TNM classification correlated with metastases. Clinical evaluation of the LN status was superior to histologic risk stratification.

Penile carcinogenesis in a low-incidence area: a clinicopathologic and molecular analysis of 115 invasive carcinomas with special emphasis on chronic inflammatory skin diseases.

BACKGROUND: Human papillomavirus (HPV) infections account worldwide for 50% of penile cancers. The role of lichen sclerosus and lichen planus in penile carcinogenesis needs further investigation. MATERIALS AND METHODS: Archival formalin-fixed high-grade penile intraepithelial neoplasias, differentiated penile intraepithelial neoplasias, and invasive carcinomas from a single pathology institution in a low-incidence area for penile cancer were analyzed for 28 HPV low-risk and HPV high-risk genotypes, p16 overexpression, presence of peritumoral lichen sclerosus, lichen planus, precursor lesions, and monoclonal rearrangement of the T-cell receptor γ locus. RESULTS: A total of 29 penile intraepithelial neoplasias (100%) and 69 of 115 (60%) invasive cancers contained HPV high-risk genotypes with a single HPV high-risk genotype (80% HPV16, 6% HPV33, 2% HPV45 and HPV18, 1% HPV73). Multiple HPV high-risk genotypes were identified in 4% with and in 5% without HPV16/18. p16 overexpression correlated in all but 1 case of HPV high-risk 45 cancer. No p16 overexpression and HPV genotype was found in 6 differentiated penile intraepithelial neoplasias and 46 of 115 (40%) invasive cancers, 30% of which were pT2/pT3 cancers. For 35 cancers, peritumoral tissue was available for analysis. Advanced lichen sclerosus was identified in 26, lichen planus in 9, and differentiated penile intraepithelial neoplasia in 18 carcinomas. Dense T-cell-dominant lymphocytic infiltrates were identified in 22 of 46 carcinomas and in 3 of 6 differentiated penile intraepithelial neoplasias, with 6 of 13 analyzed carcinomas/penile intraepithelial neoplasias showing a monoclonal rearrangement of the T-cell receptor γ locus. CONCLUSIONS: The prevalence of HPV high-risk in penile cancers from a low-incidence area was slightly higher than the global distribution. HPV-negative carcinomas were associated with advanced lichen sclerosus and lichen planus, differentiated penile intraepithelial neoplasia, and accumulation of T lymphocytes with monoclonal rearrangement of the T-cell receptor γ locus.