Immunohistochemistry and in situ hybridization for the diagnosis and classification of squamous lesions of the anogenital region

The Role of P16, P53, KI-67 and PD-L1 Immunostaining in Primary Vaginal Cancer

BACKGROUND

To analyze clinical, pathological and immunohistochemical correlates of survival in vaginal cancer patients.

METHODS

Retrospective analysis of primary vaginal cancer patients, treated at the Department of Gynecology and Gynecological Oncology of the University Hospital Bonn between 2007 and 2021.

RESULTS

The study cohort comprised 22 patients. The median age was 63 years (range: 32-87 years). Squamous cell histology was present in 20 patients. Five-year OS in Stage I, II, III and IV was 100%, 56.25%, 0% and 41.67%, respectively (p = 0.147). Five-year DFS was 100%, 50%, 0% and 20.83%, respectively (p = 0.223). The 5-year OS was significantly reduced in the presence of nodal metastasis (p = 0.004), lymphangiosis (p = 0.009), hemangiosis (p = 0.002) and an age above 64 years (p = 0.029). Positive p 16 staining was associated with significantly improved OS (p = 0.010). Tumoral and immune cell PD-L1 staining was positive in 19 and in 16 patients, respectively, without significant impact on OS; 2 patients with metastastic disease are long-term survivors treated with either bevacizumab or pembrolizumab.

CONCLUSION

P16 expression, absence of lymph- or hemangiosis, nodal negative disease and an age below 64 years show improved survival rates in PVC. Tumoral PD-L1 expression as well as PD-L1 expression on immune cells is frequent in PVC, without impacting survival. Within our study cohort, long-term survivors with recurrent PVC are treated with anti-VEGF and immunotherapy.

[The consensus of the Portuguese Society of Andrology, Sexual Medicine and Reproduction on Male HPV: diagnosis]

HPV infection affects about 50% of sexually active individuals at least once in a lifetime. Diagnosis is made on careful inspection of the genital area and can be divided into benign lesions (genital warts or condyloma acuminatum) and pre-malignant lesions (intraepithelial neoplasia) that can lead to cancer (invasive neoplasia). Diagnostic recommendations are reviewed in Male, Female, Couple and in the immunocompromised host. Recent histological concepts are also discussed.

A comparison of the detection of biomarkers in infections due to low risk versus high-risk human papillomavirus types

Adjunctive immunohistochemistry tests for human papillomavirus (HPV) infection include p16 and Ki67 as well as the more recently discovered biomarkers importin-β, exportin-5, Mcl1, and PDL1. The purpose of this study was to compare the expression of these biomarkers in HPV infection due to the high-risk types such as HPVs 16, 18, 31, 33, 35, and 51 versus lesions that contain the low risk types HPV 2, 6 or 11. We studied 35 lesions with low risk HPV types (verruca vulgaris = 10 cases, condyloma acuminatum = 15 cases, CIN 1 with HPV 6/11 = 10 cases) and 25 CIN 1 or 2 lesions with a high-risk HPV type. The 25 high-risk positive CIN 1-2 cases had strong expression of the panel p16, Ki67, importin-β, exportin-5, Mcl1, and PDL1 where each protein localized to the cells in the parabasal aspect of the lesion. In comparison, neither p16, importin-β, exportin-5, Mcl1, nor PDL1 were increased in the epithelia of the lesions with the low risk HPV types; Ki67 showed variable expression. HPV viral capsid L1 protein and viral DNA were excellent markers of infection in the lesions with low risk types. Thus, p16, importin-β, exportin-5, Mcl1, and PDL1 are not only biomarkers of high-risk HPV infection but can also differentiate such lesions from those that contain low risk HPV types. Low risk HPV infections can be best differentiated from their mimics by viral L1 capsid detection and/or HPV DNA by in situ hybridization.

New Insights into the Role of Human Papillomavirus in Anal Cancer and Anal Wart Development

Human papillomavirus is associated with several anogenital and oropharyngeal lesions, including warts, premalignant lesions, and cancer. There are specific groups that were identified as high-risk groups for anal squamous cell carcinoma and anal human papillomavirus infection, namely HIV-positive patients, men who have sex with men, women with genital tract neoplasia, and solid organ transplant recipients. Condylomas have classically been considered to be a benign lesion, with an exception made for the Buschke-Loewenstein tumor, but several publications have shown that a high percentage of condylomas harbor high-grade lesions. Due to the similarities between anal and cervical carcinogenesis, anal cancer screening based on anal cytology and referral to high-resolution anoscopy, in case of abnormalities, have been advocated. Testing for anal human papillomavirus is not routinely done in anal cancer screening, because of the very high prevalence in high-risk populations. The large majority of anal cancers are squamous cell carcinomas (SCC), and around 90% are attributed to human papillomavirus. Human papillomavirus positivity in anal SCC seems to have a prognostic value, with better survival in those patients with positive tumors. Prophylactic vaccination has been shown to be important for prevention of anal human papillomavirus-related lesions.

Significance of SYT8 For the Detection, Prediction, and Treatment of Peritoneal Metastasis From Gastric Cancer

OBJECTIVE

To develop novel diagnostic and therapeutic targets specific for peritoneal metastasis of gastric cancer (GC).

BACKGROUND

Advanced GC frequently recurs because of undetected micrometastases even after curative resection. Peritoneal metastasis has been the most frequent recurrent pattern after gastrectomy and is incurable.

METHODS

We conducted a recurrence pattern-specific transcriptome analysis in an independent cohort of 16 patients with stage III GC who underwent curative gastrectomy and adjuvant S-1 for screening candidate molecules specific for peritoneal metastasis of GC. Next, another 340 patients were allocated to discovery and validation sets (1:2) to evaluate the diagnostic and predictive value of the candidate molecule. The results of quantitative reverse-transcription PCR and immunohistochemical analysis were correlated with clinical characteristics and survival. The effects of siRNA-mediated knockdown on phenotype and fluorouracil sensitivity of GC cells were evaluated in vitro, and the therapeutic effects of siRNAs were evaluated using a mouse xenograft model.

RESULTS

Synaptotagmin VIII (SYT8) was identified as a candidate biomarker specific to peritoneal metastasis. In the discovery set, the optimal cut-off of SYT8 expression was established as 0.005. Expression levels of SYT8 mRNA in GC tissues were elevated in the validation set comprising patients with peritoneal recurrence or metastasis. SYT8 levels above the cut-off value were significantly and specifically associated with peritoneal metastasis, and served as an independent prognostic marker for peritoneal recurrence-free survival of patients with stage II/III GC. The survival difference between patients with SYT8 levels above and below the cut-off was associated with patients who received adjuvant chemotherapy. Inhibition of SYT8 expression by GC cells correlated with decreased invasion, migration, and fluorouracil resistance. Intraperitoneal administration of SYT8-siRNA inhibited the growth of peritoneal nodules and prolonged survival of mice engrafted with GC cells.

CONCLUSIONS

SYT8 represents a promising target for the detection, prediction, and treatment of peritoneal metastasis of GC.

Immunohistochemical detection of E7 human papillomavirus protein in pre‑malignant and malignant lesions of the uterine cervix

Human papillomavirus (HPV) E7 protein expression is caused by HPV viral DNA integration into human cellular DNA, and is a prerequisite for the development and progression of cervical cancer. The present study aimed to evaluate the role of E7 protein as a biomarker for identification of transformed cervical epithelial cells during the early stages of cervical cancer. Specific monoclonal antibodies to the E7 protein of high‑risk HPVs were generated and characterized for applications in immunocytochemistry and immunohistochemistry using cervical epithelial cells or biopsy tissue slides. The specificity and feasibility for detecting precancerous cells in cervical exfoliated epithelial cells was demonstrated. In addition, antibody staining of cervix biopsies indicated the pathological grades of cervical cancer and precancerous lesions. The results of the present study demonstrated the potential benefit of using E7 protein as a novel and specific clinical diagnostic marker to distinguish transient HPV infections from malignant and pre‑malignant lesions.

p16 immunostaining in histological grading of anal squamous intraepithelial lesions: a systematic review and meta-analysis

p16 is the most widely studied biomarker in lower anogenital tract squamous intraepithelial lesions and, currently the only recommended biomarker for histological grade assessment. The aim of this systematic review and meta-analysis was to evaluate p16-positive rates according to anal squamous intraepithelial lesions/anal intraepithelial neoplasia (AIN) grade. Two investigators independently searched four electronic databases: PubMed, Web of Sciences, Scopus, and Embase from inception until August 2017. Studies that evaluated p16 immunostaining in histological samples of anal and/or perianal squamous intraepithelial lesions and defined a p16-positive result as diffuse block staining with nuclear or nuclear plus cytoplasmic staining were included. A meta-analysis was performed using a random effects model. Fifteen studies consisting of 790 samples were included. The proportion of p16 expression increased with the severity of histological grade. p16 positivity was 2% (95% CI: 0.2-5%) in normal histology, 12% (95% CI: 2-27%) in low-grade squamous intraepithelial lesions (LSILs)/AIN1 (excluding condylomas), 7% (95% CI: 2-13%) in all LSIL (AIN1/LSIL/condyloma), 76% (95% CI: 61-88%) in AIN2, and 90% (95% CI: 82-95%) in AIN3. For anal high-grade squamous intraepithelial lesions (HSILs), in studies using a two-tiered nomenclature, p16 positivity was 84% (95% CI: 66-96%) and for all HSIL (AIN2, AIN3, HSIL combined) it was 82% (95% CI: 72-91%). In summary, p16 positivity in anal squamous intraepithelial lesions appears to be in a similar range to the commonly described cervical squamous intraepithelial lesions, however, for anal low-grade lesions positivity seems to be lower.

Synaptotagmin XIII expression and peritoneal metastasis in gastric cancer

BACKGROUND

Peritoneal metastasis is a frequent cause of death in patients with gastric cancer. The aim of this study was to identify molecules responsible for mediating peritoneal metastasis of gastric cancer.

METHODS

Transcriptome and bioinformatics analyses were conducted to identify molecules associated with peritoneal metastasis. The therapeutic effects of intraperitoneally administered small interfering (si) RNA were evaluated using mouse xenograft models. Expression of mRNA and protein was determined in gastric tissues from patients with gastric cancer.

RESULTS

Synaptotagmin XIII (SYT13) was expressed at significantly higher levels in patients with peritoneal recurrence, but not in those with hepatic or distant lymph node recurrence. Inhibition of SYT13 expression in a gastric cancer cell line transfected with SYT13-specific siRNA (siSYT13) was associated with decreased invasion and migration ability of the cells, but not with proliferation and apoptosis. Intraperitoneal administration of siSYT13 significantly inhibited the growth of peritoneal nodules and prolonged survival in mice. In an analysis of 200 patients with gastric cancer, SYT13 expression in primary gastric cancer tissues was significantly greater in patients with peritoneal recurrence or metastasis. A high level of SYT13 expression in primary gastric cancer tissues was an independent risk factor for peritoneal recurrence.

CONCLUSION

SYT13 expression in gastric cancer is associated with perioneal metatases and is a potential target for treatment.

Troponin I2 as a Specific Biomarker for Prediction of Peritoneal Metastasis in Gastric Cancer

BACKGROUND

Although peritoneal metastasis is a serious concern in patients with gastric cancer, no acceptable and specific biomarker is available. We aimed to identify a candidate biomarker to predict peritoneal metastasis of gastric cancer.

METHODS

Metastatic pathway-specific transcriptome analysis was conducted by comparison of patient groups with no recurrence and with peritoneal, hepatic, and nodal recurrence. Fifteen cell lines and 262 pairs of surgically resected gastric tissues were subjected to messenger RNA (mRNA) expression analysis. Polymerase chain reaction array analysis was performed to explore coordinately expressed cancer-related genes. To evaluate the in situ protein localization and expression patterns, immunohistochemical staining was performed.

RESULTS

From transcriptome data, troponin I2 (TNNI2) was identified as a candidate molecule specifically overexpressed in gastric cancer prone to peritoneal metastasis. TNNI2 mRNA was expressed at differential levels, independent of differentiated phenotype of cell lines. Epithelial to mesenchymal transition-related genes, tumor inhibitor of metalloproteinase 1 (TIMP1), and vacuolar protein sorting 13 homolog A (VPS13A) were expressed with TNNI2 at correlation coefficient > 0.7. The optimal cutoff of TNNI2 expression was determined as 0.00017. High TNNI2 expression was significantly and specifically associated with peritoneal metastasis and served as an independent risk marker for peritoneal recurrence after curative gastrectomy. Prevalence of peritoneal recurrence increased in parallel with staining intensity of TNNI2.

CONCLUSIONS

TNNI2 expression in gastric tissues may serve as a specific biomarker for prediction of peritoneal metastasis of gastric cancer and contribute to improvement of patient management.

The analysis of human papillomavirus DNA in penile cancer tissue by in situ hybridization

Primary penile cancer is a rare disease. Higher incidence rates occur in underdeveloped countries. Many studies have suggested an association between human papillomavirus (HPV) infection and penile cancer. Although HPV can affect the squamous epithelium of the male genitalia similarly to the female genital tract, the association between penile cancer and HPV remains unclear. In the present study, the HPV gene expression was examined in penile cancer tissue using in situ hybridization (ISH). The present study included 41 cases in which penectomy was performed and 3 cases in which tumor resection was performed to treat pathologically-diagnosed penile cancer at Yokohama City University Medical Center, and its 7 affiliated hospitals between April 1990 and March 2010. The penile cancer tissue was subjected to an ISH analysis, and the clinicopathological features and prognosis were investigated. A total of 5/44 cases (11.4%) showed the expression of high-risk HPV. None of the patients showed the expression of low-risk HPV. The associations between the expression of high-risk HPV, and age, tumor location, tumor size, T stage, pathological differentiation, nuclear grade, Broder's classification, pattern of invasion, Y-K grade, vascular invasion, lymphoid invasion, koilocytosis and lymph-node metastasis were then examined. Patients with a well-differentiated status (P=0.044) and Broder's Grade 1 (P=0.019) showed a significantly lower rate of HPV positivity. The HPV expression was not significantly associated with cancer specific survival (P=0.932). ISH using INFORM HPV III does not detect the HPV genotype, this method is easy to employ and may be useful for the diagnosis of penile cancer tissue, similarly to cervical cancer.

Immunohistochemical Detection of p16 in Clinical Samples

P16 immunohistochemical expression, a surrogate marker of the retinoblastoma pathway, has become a major adjunct in the routine practice mostly of cervical and head/neck pathology, but with other indications too. In this chapter, a detailed immunohistochemical technique for the detection of p16 is described, followed by indications and interpretation of its expression in uterine, ovarian, vulvar, penile, head-and-neck, melanocytic, and other pathologies.

Tumoral PD-L1 expression defines a subgroup of poor-prognosis vulvar carcinomas with non-viral etiology

Vulvar cancer is rare but incidence rates are increasing due to an aging population and higher frequencies of young women being affected. In locally advanced, metastatic or recurrent disease prognosis is poor and new treatment modalities are needed. Immune checkpoint blockade of the PD-1/PD-L1 pathway is one of the most important advancements in cancer therapy in the last years. The clinical relevance of PD-L1 expression in vulvar cancer, however, has not been studied so far. We determined PD-L1 expression, numbers of CD3⁺ T cells, CD20⁺ B cells, CD68⁺ monocytes/macrophages, Foxp3⁺ regulatory T cells and CD163⁺ tumor-associated macrophages by immunohistochemistry in 103 patients. Correlation analysis with clinicopathological parameters was undertaken; the cause-specific outcome was modeled with competing risk analysis; multivariate Cox regression was used to determine independent predictors of survival. Membranous PD-L1 was expressed in a minority of tumors, defined by HPV-negativity. Its presence geographically correlated with immunocyte-rich regions of cancer islets and was an independent prognostic factor for poor outcome. Our data support the notion that vulvar cancer is an immunomodulatory tumor that harnesses the PD-1/PD-L1 pathway to induce tolerance. Accordingly, immunotherapeutic approaches might have the potential to improve outcome in patients with vulvar cancer and could complement conventional cancer treatment.

Immunohistochemistry in Gynecologic Pathology: An Example-Based Practical Update

CONTEXT

- Immunohistochemical stains are routinely applied in the pathology diagnostic workup of gynecologic lesions. The rapidly expanding repertoire of available markers helps in refining the diagnostic criteria for each disease entity; however, limitations and pitfalls exist.

OBJECTIVE

- To provide a practical, relevant update on the use of immunohistochemistry for commonly encountered differential diagnoses in gynecologic pathology.

DATA SOURCES

- Literature review and authors' diagnostic experience.

CONCLUSIONS

- Immunohistochemistry is a helpful adjunct tool in gynecologic pathology. Although the primary application is in the diagnostic workup, novel prognostic and predictive markers, and immunostains to screen for genetic cancer syndromes, have also been recently introduced in the field.

Prevalence and distribution of 15 high-risk human papillomavirus types in squamous cell carcinoma of the scrotum

Which subtype(s) of high-risk human papillomavirus (hrHPV) are involved in squamous cell carcinoma (SCC) of the scrotum is unknown. Twenty-seven cases of SCC of the scrotum were retrieved, and all 15 subtypes of hrHPV and their viral loads were assessed using multiplex real-time polymerase chain reaction. The results were correlated with the histopathologic features, p16 expression, and in situ hybridization for hrHPV. hrHPV was identified in 18 (67%) of 27 of the cases, including HPV16 (n=8), HPV35 (n=7), HPV31 (n=5), HPV59 (n=5), HPV33 (n=3), HPV18 (n=2), HPV51 (n=2), HPV39 (n=1), HPV56 (n=1), and HPV82 (n=1). Of the 18 cases, 10 (56%) were infected by multiple hrHPV subtypes. In situ carcinomas had higher viral loads than invasive (50M versus 2M in average). The average age of HPV-positive and -negative cases was similar, 55 and 51, respectively. Of 11 cases of invasive carcinoma, 5 (45%) were positive for hrHPV versus 13 of 16 (81%) of in situ carcinomas. The highest proportion of hrHPV-positive cases was seen in basaloid type (7/7; 100%) and warty type (4/4; 100%), followed by usual type (7/16; 44%). Of 18 of the HPV-positive cases, 9 (50%) were also positive for p16 by immunohistochemistry and 6 of 18 (33%) were positive by in situ hybridization. Similar to SCC of the vulva and penis, the most frequently HPV-positive tumors are basaloid and warty types. However, a proportion of SCC usual type are also positive for hrHPV. Our results show that 8 (44%) of 18 of cases are associated with hrHPV subtypes other than 16 and 18. Additionally, 7 (70%) of 10 of hrHPV16/18-positive cases are coinfected with other subtypes.