Immunohistochemical p16 overexpression and Rb loss correlate with high-risk human papillomavirus infection in endocervical adenocarcinomas.

AIMS: p16 is a sensitive surrogate marker for transcriptionally active high-risk human papillomavirus (HR-HPV) infection in endocervical adenocarcinoma (ECA); however, its specificity is not perfect. METHODS AND RESULTS: We examined p16 and Rb expressions by immunohistochemistry (IHC) and the transcriptionally active HR-HPV infection by mRNA in-situ hybridisation (ISH) with histological review in 108 ECA cases. Thirteen adenocarcinomas of endometrial or equivocal origin (six endometrioid and seven serous carcinomas) were compared as the control group. HR-HPV was detected in 83 of 108 ECA cases (77%), including five HPV-associated adenocarcinomas in situ and 78 invasive HPV-associated adenocarcinomas. All 83 HPV-positive cases showed consistent morphology, p16 positivity and partial loss pattern of Rb. Among the 25 cases of HPV-independent adenocarcinoma, four (16%) were positive for p16, and of these four cases, three of 14 (21%) were gastric type adenocarcinomas and one of 10 (10%) was a clear cell type adenocarcinoma. All 25 HPV-independent adenocarcinomas showed preserved expression of Rb irrespective of the p16 status. Similarly, all 13 cases of the control group were negative for HR-HPV with preserved expression of Rb, even though six of 13 (46%) cases were positive for p16. Compared with p16 alone, the combination of p16 overexpression and Rb partial loss pattern showed equally excellent sensitivity (each 100%) and improved specificity (100 versus 73.6%) and positive predictive values (100 versus 89.2%) in the ECA and control groups. Furthermore, HR-HPV infection correlated with better prognosis among invasive ECAs. CONCLUSIONS: The results suggest that the combined use of p16 and Rb IHC could be a reliable method to predict HR-HPV infection in primary ECAs and mimics. This finding may contribute to prognostic prediction and therapeutic strategy.

Biological and genetic characterization of a newly established human external auditory canal carcinoma cell line, SCEACono2.

Squamous cell carcinoma of the external auditory canal (EACSCC) is an extraordinarily rare and aggressive malignant disease. Establishment of EACSCC cell line with robust molecular characteristics is essential for the basic and translational research of EACSCC. Here, we show the newly established EACSCC cell line SCEACono2, derived from a patient with well-to-moderately differentiated EACSCC. We analyzed histologic and genetic features of SCEACono2 hiring multiple experiments, including next-generation sequencing (NGS). Immunocytochemical staining of SCEACono2 showed positivity of p53 and SCC1/2. Furthermore, SCEACono2 exhibited a unique characteristic that cytokeratin, vimentin as well as cancer stem cell markers (CD44, CD133, ALP and Oct3/4) were positive. SCEACono2 had an ability to form tumors at the temporal lesion xenograft nude mice model. NGS revealed that SCEACono2 harbored the somatic mutations of TP53 (p.G245S) and NOTCH1 (p.A465T). RNA-seq and downstream bioinformatics analysis revealed significant enrichment of genes involved in inflammation and cell adhesion in SCEACono2 compared to SCC-9 and HSC-4. STR profiling indicated no evidence of cross-contamination. In conclusion, SCEACono2 could serves as a promising and robust research resource of EACSCC in vitro and in vivo.

Impact of Positive-Margin Resection of External Auditory Canal Squamous Cell Carcinoma.

BACKGROUND: Positive-margin resection of external auditory canal squamous cell carcinoma (EAC-SCC) is still a major cause of recurrence. The aim of this study is to examine the clinical impact of positive-margin resection of EAC-SCCs. METHODS: We retrospectively reviewed 40 surgical cases with en bloc temporal bone resection of EAC-SCC at a tertiary referral center from October 2016 to March 2022. RESULTS: Two-year disease-specific, overall, and disease-free survival rates for all 40 cases reviewed were 85.2%, 88.85%, and 76.96%, respectively. En bloc resection with a negative margin significantly improved patient prognosis (p < 0.001). Positive-margin resection was observed in 9/40 cases (22.5%). Insufficient assessment of preoperative images was the cause in two of these cases. Postoperative lymph node metastasis and distant metastasis were observed in cases in which vascular, lymphatic duct or perineural invasion was found on postoperative pathological examination. In addition, three cases in which no vascular, lymphatic duct, or perineural invasion was found exhibited local recurrence during the follow-up period. Of the nine positive-margin resection cases, only two showed no postoperative recurrence. CONCLUSIONS: Once positive-margin resections are confirmed, cases might have a high risk of tumor recurrence, even with the addition of postoperative adjuvant chemoradiotherapy.

Cholesterol granuloma of the anterior mediastinum: A case report and literature review.

INTRODUCTION: Cholesterol granulomas, which frequently present in the temporal bone of the skull, are recognized as benign lesions occurring due to chronic inflammation or hemorrhage. However, cholesterol granuloma of the mediastinum is extremely rare. PRESENTATION OF CASE: An asymptomatic 43-year-old man with an incidental finding of anterior mediastinal mass by positron emission tomography scan was referred to our hospital. Preoperative computed tomography showed a well-circumscribed nodule 2 cm in size in the anterior mediastinum. A total tumor resection through a suprasternal approach was performed. Microscopically, numerous cholesterol clefts with an alveolar-like growth pattern and foreign body reaction were observed, indicating a pathological diagnosis of cholesterol granuloma. DISCUSSION: Cholesterol granuloma is generally thought to be initiated by cell degeneration and hemorrhage resulting from trauma or inflammation. The patient's long-term rugby experience may have played a role in the development of cholesterol granuloma. It is difficult to diagnose a cholesterol granuloma based on preoperative imaging alone, and anatomy often makes preoperative biopsy or cytology difficult. CONCLUSION: Complete resection and pathological examination may be unavoidable for diagnosis and treatment.

HPV Infection in Squamous Cell Carcinoma of the Hypopharynx, Larynx, and Oropharynx With Multisite Involvement.

The prevalence and prognostic significance of high-risk human papillomavirus (HR-HPV) have been well-established in oropharyngeal squamous cell carcinoma (OPSCC), but not in hypopharyngeal squamous cell carcinoma (HPSCC) or laryngeal squamous cell carcinoma (LSCC). Moreover, HR-HPV infection in squamous cell carcinoma with multisite involvement has not been examined. To clarify these issues, we retrospectively collected 480 invasive tumors from 467 patients with HPSCC, LSCC, or OPSCC, and comprehensively analyzed the detailed tumor localization, transcriptionally active HR-HPV infection by messenger RNA in situ hybridization, and immunohistochemical staining for p16 and Rb. HR-HPV infection was observed in 115/480 tumors (24%). Human papillomavirus (HPV)-positive cases were closely related with p16 positivity and the partial loss pattern of Rb. HR-HPV was detected in 104 of 161 tumors (64.6%) in the pure OPSCC group and only 1 of 253 tumors (0.4%) in the pure HP/LSCC group; the positive case occurred in the vocal cords. In the multisite-involving combined-type squamous cell carcinoma group, HPV infection was observed in 10/40 (25%) cases, and the 10 HPV-positive cases had OPSCC extending to the larynx or hypopharynx. Among high T-stage (T3/T4) cases of pure OPSCC, HPV-positive cases showed a better prognosis ( P =0.0144), whereas the HPV-positive combined OPSCC group did not show a better prognosis ( P =0.9428), as compared with HPV-negative counterpart. The results suggest that HR-HPV infection in pure HPSCC and LSCC may be extremely rare. HR-HPV infection seems to be present in a substantial proportion of patients with combined OPSCC and HPSCC/LSCC, but it may not improve prognosis at such advanced disease stages. Confirmation of these points awaits future studies with larger cohorts.

High-risk HPV-related squamous cell carcinoma in the temporal bone: a rare but noteworthy subtype.

High-risk human papillomavirus (HPV) is a risk factor for the development of several head and neck squamous cell carcinomas (SCCs). However, there have been few reports of high-risk HPV infection in temporal bone squamous cell carcinomas (TBSCCs), and thus the prevalence and clinicopathologic significance of high-risk HPV in TBSCCs are still unclear. We retrospectively collected 131 TBSCCs and analyzed them for transcriptionally active high-risk HPV infection using messenger RNA in situ hybridization; we also assessed the utility of p16-immunohistochemistry (IHC) and Rb-IHC to predict HPV infection. Eighteen (13.7%) of the 131 TBSCCs were positive for p16-IHC, and five of them were positive for high-risk HPV infection (the estimated high-risk HPV positivity rate was 3.8% [5/131]). Interestingly, all five HPV-positive patients were male and had TBSCC on the right side. In the p16-IHC+/HPV+ cases (n = 5), the Rb-IHC showed a partial loss pattern (n = 4) or complete loss pattern (n = 1). In contrast, all p16-IHC-negative cases (n = 113) showed an Rb-IHC preserved pattern. The positive predictive value (PPV) of p16-IHC positivity for high-risk HPV infection was low at 27.8%, while the combination of p16-IHC+/Rb-IHC partial loss pattern showed excellent reliability with a PPV of 100%. The prognostic significance of high-risk HPV infection remained unclear. High-risk HPV-related TBSCC is an extremely rare but noteworthy subtype.

Real-world Experience With Pembrolizumab for Advanced-stage Head and Neck Cancer Patients: A Retrospective, Multicenter Study.

BACKGROUND/AIM: This study investigated the effectiveness of pembrolizumab with or without chemotherapy on advanced-stage head and neck cancer (HNC), including nasopharyngeal, sinonasal cavity and external auditory canal cancer, in a real-world setting. PATIENTS AND METHODS: We retrospectively collected data from 97 HNC patients who were treated with pembrolizumab alone (n=60) or with chemotherapy (n=37), and we investigated the association between clinicopathological findings and treatment response or prognosis. RESULTS: Patients treated with pembrolizumab and chemotherapy had a 1-year overall survival (OS) of 72.8%, objective response rate (ORR) of 48.6%, and serious (≥G3) adverse events (AEs) of 29.7%. Patients treated with pembrolizumab alone had a 1-year OS of 51.9%, ORR of 21.7%, and ≥G3 AEs of 6.7%. Both the ORR and disease control rate (DCR) in the pembrolizumab with chemotherapy group were significantly better than those in the pembrolizumab group (p=0.074 and p=0.00101, respectively). Among patients with distant metastasis, patients on pembrolizumab with chemotherapy achieved significantly better OS than pembrolizumab alone (p=0.0039). Among patients in the pembrolizumab group, both AE-positive and better performance status were associated with longer OS (p=0.011 and p=0.0037, respectively). CONCLUSION: Our real-world experience reinforces the durability and effectiveness of pembrolizumab for HNC patients. Additionally, our results suggest that pembrolizumab with chemotherapy might be recommended for patients with distant metastasis and no prior treatment. Further studies are needed to determine the optimal treatment strategy for HNC.

Retrospective Study of Cisplatin/Carboplatin, 5-Fluorouracil Plus Cetuximab (EXTREME) for Advanced-stage Salivary Gland Cancer.

BACKGROUND/AIM: Surgery remains the standard treatment for salivary gland carcinoma (SGC). Our study investigated the association between epidermal growth factor receptor (EGFR) status in recurrent/metastatic SGC and the effectiveness of treatment with cisplatin/carboplatin and 5-fluorouracil plus cetuximab (EXTREME). PATIENTS AND METHODS: We retrospectively collected 19 SGCs from patients treated with the EXTREME regimen. After analyzing EGFR expression and gene copy number gain, we evaluated the correlation between EGFR status and clinicopathological factors and prognosis. RESULTS: EGFR overexpression was detected in 77.8% cases, but not statistically associated with clinicopathological factors or prognosis. EGFR gene copy number gain was detected in 16.7% cases, and statistically positively correlated with lymph node metastasis (p=0.0291). The best overall response was partial response in two cases, stable disease in 15, and progressive disease in one case. The EXTREME regimen was discontinued in all cases. CONCLUSION: Our results suggest that SGCs are positive for EGFR protein expression but the response rate to the EXTREME regimen was unremarkable.

Treatment Efficacy of PD-1 Inhibitor Therapy in Patients With Recurrent and/or Metastatic Salivary Gland Carcinoma.

BACKGROUND/AIM: The efficacy of programmed cell death 1 (PD-1) inhibitor therapy for patients with recurrent and/or metastatic salivary gland carcinoma (R/M SGC) remains unclear. PATIENTS AND METHODS: We retrospectively analyzed 36 patients with R/M SGC treated with PD-1 inhibitor. The expression of programmed cell death ligand 1 (PD-L1) and mismatch repair (MMR) proteins was also analyzed. RESULTS: The objective response rate (ORR) was 11.1%. The histopathological subtypes of patients who achieved complete response or partial response were salivary duct carcinoma (SDC) in three patients and poorly differentiated carcinoma in one patient, all of whom showed a positive PD-L1 expression. The expression of MMR proteins was not associated with the efficacy of PD-1 inhibitors. CONCLUSION: Although the efficacy of PD-1 inhibitor therapy in R/M SGC is limited, certain patients may respond and achieve long-term disease control. There is a potential therapeutic effect in SDC patients with positive PD-L1 expression.

A clinical analysis of oropharyngeal squamous cell carcinoma: a single-institution's experience.

PURPOSE: We herein report the treatment outcome of oropharyngeal squamous cell carcinoma (OPSCC) at Kyushu University Hospital, the total number of OPSCC cases, and changes in the proportion of human papilloma virus (HPV)-related carcinomas over time. METHOD: We performed a retrospective analysis of 237 cases treated for OPSCC at Kyushu University Hospital between 2013 and 2019. We performed HPV-mRNA in situ hybridization and p16 immunohistochemistry. RESULT: This study included 197 males (82.1%) and 40 females (17.9%). The disease-specific, progression-free and overall survival (OS) were 69%, 62% and 61%, respectively, over the decade-long study period. p16-Immunohistochemistory and highrisk HPV mRNA in situ hybridization were positive in 114 (48.1%) and 105 (44.3%) cases, respectively. The number of HPV-related OPSCC cases increased according to an annual analysis. HPV+ cases had a significantly better prognosis than HPV- cases. In addition, p16+/HPV- cases had a significantly worse prognosis than p16+/HPV+ cases (OS: p = 0.0484). HPV+ OPSCC cases were associated with a younger age (< 60 years old) (p = 0.0429), non-smoker (p = 0.0001), lateral tumor site (< 0.00001), lymphoid metastasis (< 0.0001) and low clinical stage (< 0.0001). CONCLUSION: The frequency of HPV-related OPSCC cases is increasing in Japan as well as worldwide, and such cases are characterized by no smoking habit, a young age, and a good prognosis. Even in p16+ OPSCC, HPV- cases had a poor prognosis, suggesting the importance of accurate HPV determination. To determine the intensity of treatment for HPV-related and non-related OPSCC, it is necessary to accumulate cases for the accurate HPV determination and comparison of treatment effects.

High-risk HPV-related Squamous Cell Carcinoma in the Conjunctiva and Lacrimal sac: Clinicopathologic Characteristics and Diagnostic Utility of p16 and Rb Immunohistochemistry.

High-risk human papillomavirus (HPV) infection in conjunctival and lacrimal sac squamous cell carcinomas (SCCs) has been sporadically reported; however, its prevalence, clinicopathologic significance and surrogate markers have not been fully elucidated. Here, we attempted to clarify these questions in Japanese patients with conjunctiva and lacrimal sac SCCs. We retrospectively collected 51 conjunctival SCC and 7 lacrimal sac SCC samples and analyzed them for (1) transcriptionally active high-risk HPV infection using messenger RNA in situ hybridization and (2) protein expressions of p16 and Rb using immunohistochemistry (IHC). Among a total of 58 cases, 25 (43.1%) and 16 (27.6%) tumors were positive for p16-IHC and HPV in situ hybridization, respectively. Ten (19.6%) of the 51 conjunctival SCCs, especially in the palpebral conjunctiva, and 6 (85.7%) of the 7 lacrimal sac SCCs were positive for high-risk HPV. High-risk HPV infection was significantly associated with younger patients, nonkeratinizing SCC histology, p16-positivity and partial loss of Rb expression, but not with recurrence risk. Notably, p16-IHC was not a perfect surrogate marker for high-risk HPV infection; only 64% (16/25) of p16-positive tumors were positive for high-risk HPV. In contrast, the p16+/Rb partial loss pattern was exclusively correlated with high-risk HPV-positivity. The results suggest that the combination of p16 and Rb expression patterns by IHC could be a useful method to predict high-risk HPV infection in conjunctival and lacrimal sac SCCs. HPV infection may be of less prognostic value in this field of cancers.

PD-L1 expression, tumor-infiltrating lymphocytes, mismatch repair deficiency, EGFR alteration and HPV infection in sinonasal squamous cell carcinoma.

The antitumor efficacies of immune checkpoint inhibitors (ICIs) and the usefulness of potential predictive markers such as programmed death-ligand 1 (PD-L1) expression, density of tumor-infiltrating lymphocytes (TILs) and microsatellite instability (MSI) in sinonasal squamous cell carcinoma (SNSCC) have not been fully elucidated. We retrospectively analyzed 131 SNSCCs with immunohistochemistry for PD-L1 expression, TIL subpopulations and loss of mismatch repair (MMR) proteins as a surrogate for MSI-high. We also comprehensively evaluated the mutual relationships among these immuno-markers, high-risk human papillomavirus (HPV) infection, epidermal growth factor receptor (EGFR) gene status, and KRAS mutation. PD-L1 expression (tumor proportion score ≥ 1%) was detected in 60 (45.8%) SNSCC cases and was significantly associated with worse overall survival (OS) (p = 0.0240). High density of cluster of differentiation 8 (CD8)-positive TILs was significantly associated with better progression-free survival (PFS) (p = 0.0368), and high density of forkhead box protein P3-positive TILs was significantly associated with better PFS and OS (p = 0.0007 and 0.0143, respectively). With respect to the combination of CD8 + TIL and PD-L1 expression, the high-CD8/PD-L1-negative group showed the most favorable prognosis, whereas the low-CD8/PD-L1-positive group showed the worst prognosis. MMR loss was detected in 3 (2.3%) of the 131 cases. HPV infection (6.1%), EGFR mutation (14.5%), EGFR copy number gain (26%), and MMR loss were essentially mutually exclusive; patients in these molecular groups showed significant differences in prognosis but not in the degree of PD-L1 expression or TILs. Among the nine ICI-treated patients, three (33.3%) were responders, and the EGFR-wild type cases (n = 7) showed better clinical responses to an ICI compared to the EGFR-mutant cases (n = 2). Among the patients with residual/recurrent EGFR-wild type tumors (n = 43), ICI treatment significantly improved OS (p = 0.0281). The results suggest that the evaluation of immuno-markers and molecular subclassification may be helpful for prognostic prediction and selecting an individualized therapeutic strategy for patients with SNSCC.

Programmed Death-Ligand 1 Expression and Tumor-Infiltrating Lymphocytes in Temporal Bone Squamous Cell Carcinoma.

OBJECTIVES/HYPOTHESIS: The tumor immune microenvironment in temporal bone squamous cell carcinoma (TBSCC), including the programmed death-ligand 1 (PD-L1) expression and tumor-infiltrating lymphocytes (TILs), has not been established. STUDY DESIGN: Retrospective cohort study. METHODS: We performed immunohistochemistry analyses to retrospectively analyze 123 TBSCC cases for PD-L1 expression and TILs and their prognostic significance. We also evaluated the prognostic correlations between these immunomarkers and the therapeutic responses to chemoradiotherapy (CRT). RESULTS: PD-L1 expression (≥1%) was detected in 62 (50.4%) TBSCC cases and was significantly associated with worse prognosis: progression-free survival (PFS), P < .0001; overall survival (OS), P = .0009. A high density of CD8+ TILs was significantly associated with better prognosis (PFS, P = .0012; OS, P = .0120). In contrast, a high density of Foxp3+ TILs tended to be associated with an unfavorable prognosis (PFS, P = .0148; OS, P = .0850). With regard to the tumor microenvironment subtypes defined by CD8+ TILs and PD-L1 expression, the CD8low /PD-L1+ group showed significantly worse prognosis. Among the 36 neoadjuvant CRT-treated cases, PD-L1 expression was significantly associated with worse OS (P = .0132). Among the 32 CRT-treated cases without surgery, a high density of CD8+ TILs tended to be more highly associated with complete response to CRT compared to a low density of CD8+ TILs (P = .0702). CONCLUSIONS: These results indicate that the evaluation of the tumor immune microenvironment may contribute to the prediction of prognoses and the selection of an individualized therapeutic strategy for patients with TBSCC. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:2674-2683, 2021.