Value of p16(INK)4(a) in the pathology of invasive penile squamous cell carcinomas: A report of 202 cases.

BACKGROUND: One third to one half of penile squamous cell carcinomas (SCCs) are related to human papillomavirus (HPV) infection. Viral detection is usually carried out by polymerase chain reaction (PCR) or other molecular methods. In this study, we evaluated p16(INK)4(a) immunohistochemical expression, which is simpler and less costly, as a potential marker of high-risk HPV (HR-HPV) infection in penile SCC. DESIGN AND METHODS: We pathologically classified 202 invasive penile carcinomas and performed HPV genotyping by short PCR fragment (SPF)10 PCR and p16(INK)4(a) immunohistochemistry. We also evaluated HPV and p16(INK)4(a) according to the histologic subtypes of penile SCC. Tumors depicting continuous p16(INK)4(a) immunostain in all neoplastic cells were considered positive. HPV and p16(INK)4(a) status were compared using classifier performances and concordance indexes. RESULTS: Evidence of HPV (low-risk and high-risk genotypes) was found in 63 cases (31%) by PCR. Fifty-three p16(INK)4(a)-positive cases were identified (26%). Overexpression of p16(INK)4(a) had a sensitivity of 67% and a specificity of 91% for defining the HPV status. Concordance indexes between p16(INK)4(a) and HPV status were high (≥78%) in general cases and in all histologic subtypes of penile SCC. The stain was useful in the differential diagnosis of basaloid and low-grade warty carcinomas. Low-risk HPV genotypes were found in 5 tumors, 4 of which were p16(INK)4(a) negative. Basaloid and nonbasaloid high-grade (grade 3) SCCs were more likely to be HR-HPV positive when compared with grades 1 to 2 tumors (P<0.000001 and 0.0417, respectively). CONCLUSIONS: p16(INK)4(a) overexpression was found to be a reliable marker for HR-HPV and a helpful tool in the differential diagnosis of low-grade verruciform and high-grade solid penile tumors. SCC variants depicting basaloid features were more likely to be HPV and p16(INK)4(a) positive than low-grade, keratinizing lesions. We also observed a tendency toward HPV positivity in high-grade nonbasaloid tumors. Our results indicated a concordance between HPV and p16(INK)4(a) status and this observation may have diagnostic and prognostic implications.

Human papillomavirus prevalence and type-specific relative contribution in invasive cervical cancer specimens from Italy.

BACKGROUND: Cervical cancer represents an important global public health problem. It is the 2nd most common cancer among women worldwide. Human papillomavirus (HPV) infection is now well-established as a necessary cause of invasive cervical cancer (ICC) development. Only a few studies on HPV prevalence and type-specific distribution in ICC have been conducted in Italy. AIM: To describe the prevalence of HPV and the HPV type-specific distribution in ICC cases identified in Rome, Italy. METHODS: 140 paraffin embedded tissue blocks of primary ICC diagnosed between 2001 and 2006 were identified at the Regina Elena Cancer Institute in Rome (Italy). HPV was detected through amplification of HPV DNA using SPF-10 HPV broad-spectrum primers followed by DEIA and then genotyping by LiPA25 (version 1). RESULTS: 134 cases were considered suitable for HPV DNA detection after histological evaluation; and overall, 90.3% (121/134) HPV prevalence was detected. 111 cases had a single HPV type, 4 cases had an uncharacterized type (HPVX) and 6 cases had multiple HPV infections. The five most common single HPV types among positive cases were: HPV16 (71/121; 58.7%), HPV18 (12/121; 9.9%), HPV31, HPV45 and HPV58 (5/121; 4.1% each). 2 (1.5%) of the single infections and 2 (1.5%) of the multiple infections contained low risk types. Statistically significant differences in the relative contribution of HPV18 were found when comparing squamous cell carcinomas with adenocarcinomas. CONCLUSIONS: HPV16 and HPV18 accounted for almost 70% of all the HPV positive ICC cases. The study provides baseline information for further evaluation on the impact of recently introduced HPV vaccines in Italy.

The basaloid cell is the best tissue marker for human papillomavirus in invasive penile squamous cell carcinoma: a study of 202 cases from Paraguay.

Human papillomavirus (HPV) has been reported in 12-82% of penile squamous cell carcinomas (SCC). There is an association of the virus with basaloid and warty carcinomas but the reported prevalence is variable. The causes of these variations are not clear. They may be owing to geographic differences, the use of different techniques to detect HPV, the status of the original paraffin blocks, or to variable criteria in tumor classification. The aims of the study were to determine the prevalence of HPV in penile SCC and subtypes using a sensitive technique, to investigate genotypes involved, and to search for other morphologic features associated with the virus from a series of cases from Paraguay. HPV detection was done by SPF-10 polymerase chain reaction followed by DNA enzyme-immunoassay and genotyping by LIPA 25 (version 1). Samples were tested at Catalan Institute of Oncology, Barcelona, and cross testing was carried out at the Delft Diagnostic Laboratories in The Netherlands. HPV was detected in 64 of 202 cases (32%). Thirteen tumors had multiple HPV genotypes. Most prevalent genotypes were HPV-16 (46 cases), HPV-6 (6 cases), and HPV-18 (4 cases), either in single or in multiple infections. HPV was preferentially associated with warty-basaloid (82%), basaloid (76%), and warty (39%) carcinomas and not detected in verrucous, mixed verrucous-papillary, pseudohyperplastic, and pseudoglandular SCCs. There was a strong association between HPV and higher histologic grade. Basaloid cells were more frequently found in HPV positive tumors (72%) and this association was statistically significant in univariate and multivariate analyses. Cells with koilocytotic features and keratinizing squamous cells were also present but to a much lesser degree (47% and 19%, respectively). In summary, HPV was found in a third of the cases and the most common genotype was HPV-16. Low-risk genotypes were rarely found in single infections, representing 4 cases among all analyzed (2%). There was an association between HPV presence and higher histologic grade and with basaloid, warty-basaloid, and warty carcinomas. Our results also suggest that, in penile SCC, the basaloid cell is the best tissue marker for oncogenic HPV infection.