Probes for HPV

Routine testing for p16 immunohistochemistry (with selective HPV-specific test use) has been recommended for clinical practice in oropharyngeal squamous cell carcinoma (OPSCC). Data suggests that the E6H4 clone performs best for this purpose, yet no studies have evaluated the optimal antibody concentration for OPSCC testing. We evaluated three concentrations (undiluted, 1:5, and 1:10) of the primary antibody solution for E6H4 using tissue microarrays from a cohort of 199 OPSCC patients with a > 70% staining cutoff for positivity. Concordance was evaluated using percent agreement and Cohen's kappa. The concentrations were evaluated for sensitivity and specificity using high risk HPV RNA in situ hybridization (RNA-ISH) and also correlated with Kaplan-Meier overall survival analysis. Inter-rater agreement was very high between p16 results at each concentration and also with RNA in situ hybridization (p < 0.0001 for all). Agreement between p16 undiluted and 1:5 dilution (agreement 98.2%; Kappa 0.943; p < 0.0001) was very high and between p16 undiluted and 1:10 dilution (agreement 79.2%; Kappa 0.512; p < 0.0001) much lower. Intensity of the staining did decrease with the 1:5 and 1:10 dilutions compared to undiluted, but not in a manner that obviously would change test interpretation or performance. Results suggest that the E6H4 antibody performs well at dilutions of up to 1:5 fold with a minor decrease in staining intensity, minimum loss of sensitivity, and no loss of specificity in OPSCC patients. This could result in reagent and cost savings.

Abstract

OBJECTIVE:

The Silva invasion pattern-based classification system stratifies endocervical adenocarcinomas (ECAs) into 3 categories corresponding to risk of metastasis and recurrence, but has only been evaluated for HPV-associated ECAs of usual type. We examined whether the Silva system is applicable to all endocervical adenocarcinomas, especially those not associated with HPV.

METHODS:

Complete slide sets from 341 surgical specimens of ECA were collected from 7 institutions worldwide. All specimens were associated with clinical records covering at least 5 years of follow-up. Tumors were classified as HPV-associated (HPVA) or not (NHPVA) by both morphology and detection of HPV using in situ hybridization. Recurrence and survival were analyzed by multivariate Mantel-Haenszel methods.

RESULTS:

Most specimens (292; 85.6%) were HPVA, while 49 (14.3%) were NHPVA. All NHPVAs were Silva pattern C, while 76.0% of HPVAs were pattern C, 14.7% pattern A, and 9.3% pattern B. Including both HPVAs and NHPVAs, lymphovascular invasion (LVI) was detected in 0% of pattern A, 18.5% of pattern B and 62.6% of pattern C cases (p < 0.001). None of the pattern A or B cases were associated with lymph node metastases (LNM), in contrast to pattern C cases (21.8%). Among patients with Silva pattern C ECA, those with HPVA tumors had a lower recurrence rate and better survival than those with NHPVA; however, when adjusted for stage at diagnosis, the difference in recurrence and mortality was small and not statistically significant.

CONCLUSIONS:

Application of the Silva system is only relevant in HPVA cervical adenocarcinoma.

Although 2014 World Health Organization criteria require unequivocal glandular and squamous differentiation for a diagnosis of cervical adenosquamous carcinoma, in practice, adenosquamous carcinoma diagnoses are often made in tumors that lack unequivocal squamous and/or glandular differentiation. Considering the ambiguous etiologic, morphological, and clinical features and outcomes associated with adenosquamous carcinomas, we sought to redefine these tumors. We reviewed slides from 59 initially diagnosed adenosquamous carcinomas (including glassy cell carcinoma and related lesions) to confirm an adenosquamous carcinoma diagnosis only in the presence of unequivocal malignant glandular and squamous differentiation. Select cases underwent immunohistochemical profiling as well as human papillomavirus (HPV) testing by in situ hybridization. Of the 59 cases originally classified as adenosquamous carcinomas, 34 retained their adenosquamous carcinoma diagnosis, 9 were reclassified as pure invasive stratified mucin-producing carcinomas, 10 as invasive stratified mucin-producing carcinomas with other components (such as HPV-associated mucinous, usual-type, or adenosquamous carcinomas), and 4 as HPV-associated usual or mucinous adenocarcinomas with benign-appearing squamous metaplasia. Two glassy cell carcinomas were reclassified as poorly differentiated usual-type carcinomas based on morphology and immunophenotype. There were significant immunophenotypic differences between adenosquamous carcinomas and pure invasive stratified mucin-producing carcinomas with regard to HPV (p < 0.0001), PAX8 (p = 0.038; more in adenosquamous carcinoma), p40 (p < 0.0001; more in adenosquamous carcinoma), p63 (p = 0.0018; more in adenosquamous carcinoma) and MUC6 (p  < 0.0001; less in adenosquamous carcinoma), HNF-1beta (p = 0.0023), vimentin (p = 0.0003), p53 (p = 0.0004), and CK7 (p = 0.0002) expression. Survival outcomes were similar between all groups. Adenosquamous carcinomas should be diagnosed only in the presence of unequivocal malignant glandular and squamous differentiation. The two putative glassy cell carcinomas studied did not meet our criteria for adenosquamous carcinoma, and categorizing them as such should be reconsidered.

Abstract

Background

Laryngeal squamous cell carcinoma (LSCC) is strongly associated with tobacco use, but recent reports suggest an increasing incidence of LSCC in patients without traditional risk factors, suggesting an alternative etiology of tumorigenesis. The purpose of this study is to characterize this non-smoking population and to compare immunohistochemical markers in tumor specimens from non-smokers and smokers with LSCC.

Methods

A retrospective chart review of patients with LSCC at Johns Hopkins Hospital (JHH) was performed. A tissue microarray (TMA) was constructed with tumor specimen from non-smokers with stage and age-matched smokers and stained for a variety of immunologic and molecular targets.

Results

In the JHH cohort of 521 patients, 12% (n = 63) were non-smokers. Non-smokers were more likely to be <45 years old at time of diagnosis (OR 4.13, p = 0.001) and to have glottic tumors (OR 2.46, p = 0.003). The TMA was comprised of tumors from 34 patients (14 non-smokers, 20 smokers). Only 2 patients (6%) were human-papillomavirus (HPV) positive by high-risk RNA in situ hybridization (ISH). There was no correlation between smoking status and p16 (p = 0.36), HPV-ISH positivity (p = 0.79), phosphatase and tensin homolog (PTEN, p = 0.91), p53 (p = 0.14), or programmed death-ligand 1 (PD-L1, p = 0.27) expression.

Conclusions

Non-smokers with LSCC are more likely to be younger at the time of diagnosis and have glottic tumors than smokers with LSCC. In TMA analysis of stage and age-matched specimens from smoker and non-smokers with LSCC, the pattern of expression for common molecular and immunologic markers is similar. Further, HPV does not appear to be a major causative etiology of LSCC in either smokers or non-smokers in our cohort of patients.