p16INK4 expression is of prognostic and predictive value in oropharyngeal cancers independent of human papillomavirus status: a Hungarian study

A Study of Prognostic Factors in Young Patients With Non-HPV Oral Cancer in Central Europe

The etiological factors of squamous cell carcinomas of the head and neck have been well known for a long time. It is also well known that the incidence of oral cancer diagnosed in younger patients is on the rise. Due to the young age of these patients, the increase in the number of these cases and the fact that many of them neither smoke nor drink alcohol it has been suggested that other factors might be at play in the carcinogenesis of oral cancer. Thus, along the classic etiological factors of smoking and alcohol abuse certain molecular marker anomalies and the human papilloma virus (HPV) have emerged as potential factors. The aim of the present study is to verify the potential prognostic factors and to map the differences in biomarker expression between the young and the old patient groups. In the present study the immunohistochemical profile of samples obtained from oral squamous cell carcinomas was studied and compared with various clinico-pathological parameters. In 88 samples the expressions of p16, p53, Ki67, EGFR were studied with a tissue microarray technique under standard reaction conditions as well as the detection and typing of HPV infection with the Full Spectrum HPV DNA method. The biomarker expression profile of young patients with oral squamous cell carcinoma was compared to that of older patients (above 50). A significant difference was found between the immunohistochemical profile of the young and old patient groups in p16, Ki67 expression. The overall survival and progression free survival were influenced by p16 expression in young age.

Different patterns of p16INK4a immunohistochemical expression and their biological implications in laryngeal squamous cell carcinoma

Introduction: p16^INK4a immunohistochemistry (IHC) is widely used to facilitate the diagnosis of human papillomavirus (HPV)-associated neoplasia, when ≥70% of cells show strong nuclear and cytoplasmic positivity. In this study, we aim to compare partial expression patterns that do not fulfill the above criteria and seek biological implications in laryngeal squamous cell carcinoma (LSCC). Materials and Methods: p16^INK4a IHC staining was conducted on representative sections of archived tissue from 88 LSCCs. Immunoreactivity was described based on four parameters: intracellular localization of immunostaining, intensity of immunostaining, distribution pattern and percentage of positive cells. Results: Six patterns of p16^INK4a immunoexpression were observed and defined as: strong diffuse (strong immunostaining, expression in cytoplasm and nucleus in >70% of tumor cells), weak diffuse (moderate or weak immunostaining, expression in cytoplasm in >70% of tumor cells), marginal (strong cytoplasmic immunostaining, limited to the periphery of tumor islets), strong scattered (strong immunostaining, expression in cytoplasm and nucleus in <50% of tumor cells), weak scattered (moderate or weak immunostaining, expression in cytoplasm in <50% of tumor cells), negative (no expression). The pN stage of the patients was associated with p16^INK4a immunoexpression patterns, the marginal pattern was only found in the pN0-Nx stages, while the weak diffuse pattern was more frequently observed in pN2-N3 stages. Conclusions: Partial immunostaining with architecturally distinct p16^INK4a immunoexpression patterns may prove significant in stratifying characteristic clinicopathological subgroups among LSCC. Our observations may support the hypothesis that p16^INK4a has different roles in different subcellular locations, with tumorigenic molecular pathways unrelated to HPV infection.

Expression of PD-L1 on Immune Cells Shows Better Prognosis in Laryngeal, Oropharygeal, and Hypopharyngeal Cancer

Despite great enthusiasm towards immunotherapy, reliable biomarkers are still lacking. The importance of subsets based on human papillomavirus (HPV) status is supported by a growing body of evidence. However, role of other possible subgroups such as anatomic localization of primary tumor remains controversial. Our objective was to investigate immune cell infiltrate and checkpoint inhibitor proteins in above-mentioned head and neck cancer subsets. Archival tumor samples of 106 laryngeal, oropharyngeal, and hypopharyngeal cancer patients were stained with PD-L1, PD-L2, PD-1, and CTLA-4 antibodies. Proportion of tumor-infiltrating lymphocytes was assessed as well. In HPV-negative tumors, PD-L1 immune cell positivity was associated with better disease-specific survival. PD-L1 expression on immune cells correlated with improved disease-specific survival in laryngeal tumors. Furthermore, PD-L1 immune cell positivity correlated with CTLA-4 expression on immune cells and it was accompanied by high tumor-infiltrating lymphocyte rate. PD-L1 expression on tumor cells and PD-1 status showed strong correlation in all patients and in oropharyngeal and laryngeal localization, but not in hypopharynx. HPV-negative oropharyngeal cancers showed negative PD-L1 status on tumor cells. CTLA-4 positivity was observed in 49.5% and 20.6% on immune cells and on tumor cells, respectively. We concluded that PD-L1 expression on immune cells indicates better prognosis in laryngeal squamous cell carcinoma and in HPV-negative head and neck squamous cell carcinoma. We have not found any essential differences between anatomic subgroups. A possibly distinct role of hypopharyngeal localization regarding immune activity requires further clarification.

Prognostic Significance of Glutathione Peroxidase Levels (GPx1) in Head and Neck Cancers

INTRODUCTION

To date, no reliable prognostic biological marker for all squamous cell carcinoma located in different subsites of the head and neck region has been identified and used in daily routine. In line with our previous studies, in which we showed a role of glutathione and associated enzymes as potential biological markers, we investigated the relationship between GPx1 and prognosis of head and neck squamous cell carcinoma.

METHODS

The association between GPx1 and patient and tumor related factors were investigated in 87 pretreatment biopsies from head and neck cancer patients treated by (chemo)radiation. Moreover, the influence of GPx1 expression on outcome parameters was assessed.

RESULTS

A significant difference was found in the T-stage between the low and high-expressing GPx1 groups. About 75% of the T3-T4 tumors were considered GPx1 low-expressing tumors, while low GPx1 expression was only seen in 25% of the T1-T2 tumors. There was also a significant difference found between the groups when looking at the different tumor sites. Local control, locoregional control, disease-free survival, and overall survival were the same in both groups. All these results indicate that GPx1 expression does not influence the radiotherapy response nor survival.