Comparison of PI3K Pathway in HPV-Associated Oropharyngeal Cancer With and Without Tobacco Exposure

Clinical and molecular characteristics of Jordanian oropharyngeal cancer patients according to P16 expression: a retrospective study and a report of a novel biomarker

The purpose of this study was to assess the clinicopathological features of oropharyngeal cancer patients in Jordan based on their HPV status. Sixty-nine biopsies from two hospitals were included. Tissue microarrays were prepared from formalin-fixed paraffin-embedded (FFPE) specimens and stained with antibodies for CDKN2A/P16, EGFR, PI3K, PTEN, AKT, pS473AKT, PS2mTOR, and TIMAP. The cohort was divided according to P16 expression. Chi-square test and survival analyses were employed to evaluate the variations among the study variables and determine the prognostic factors, respectively. P16 expression was found in 55.1% of patients; however, there was no significant association between P16 expression and the patients' clinicopathological features. The Kaplan-Meier test revealed that smoking in P16-positive group and younger age (< 58 years) negatively impacted disease-free survival (DFS) (P = 0.04 and P = 0.003, respectively). Multivariate Cox regression test indicated that smoking, age, PI3K, and AKT were negative predictors of DFS (P = 0.021, P = 0.002, P = 0.021, and P = 0.009, respectively), while TIMAP was a positive predictor (P = 0.045). Elevated P16 expression is found in more than half of the patients' specimens. DFS is negatively affected by younger age and the combined effect of smoking and P16 overexpression. TIMAP is overexpressed in P16-positive oropharyngeal cancer, and it is a favorable predictor of DFS.

PI3K/AKT/mTOR Signaling Pathway in HPV-Driven Head and Neck Carcinogenesis: Therapeutic Implications

High-risk human papillomaviruses (HR-HPVs) are the causal agents of cervical, anogenital and a subset of head and neck carcinomas (HNCs). Indeed, oropharyngeal cancers are a type of HNC highly associated with HR-HPV infections and constitute a specific clinical entity. The oncogenic mechanism of HR-HPV involves E6/E7 oncoprotein overexpression for promoting cell immortalization and transformation, through the downregulation of p53 and pRB tumor suppressor proteins, among other cellular targets. Additionally, E6/E7 proteins are involved in promoting PI3K/AKT/mTOR signaling pathway alterations. In this review, we address the relationship between HR-HPV and PI3K/AKT/mTOR signaling pathway activation in HNC with an emphasis on its therapeutic importance.

Interaction between Cigarette Smoke and Human Papillomavirus 16 E6/E7 Oncoproteins to Induce SOD2 Expression and DNA Damage in Head and Neck Cancer

Even though epidemiological studies suggest that tobacco smoking and high-risk human papillomavirus (HR-HPV) infection are mutually exclusive risk factors for developing head and neck cancer (HNC), a portion of subjects who develop this heterogeneous group of cancers are both HPV-positive and smokers. Both carcinogenic factors are associated with increased oxidative stress (OS) and DNA damage. It has been suggested that superoxide dismutase 2 (SOD2) can be independently regulated by cigarette smoke and HPV, increasing adaptation to OS and tumor progression. In this study, we analyzed SOD2 levels and DNA damage in oral cells ectopically expressing HPV16 E6/E7 oncoproteins and exposed to cigarette smoke condensate (CSC). Additionally, we analyzed SOD2 transcripts in The Cancer Genome Atlas (TCGA) Head and Neck Cancer Database. We found that oral cells expressing HPV16 E6/E7 oncoproteins exposed to CSC synergistically increased SOD2 levels and DNA damage. Additionally, the SOD2 regulation by E6, occurs in an Akt1 and ATM-independent manner. This study suggests that HPV and cigarette smoke interaction in HNC promotes SOD2 alterations, leading to increased DNA damage and, in turn, contributing to development of a different clinical entity.

An ErbB Lineage Co-Regulon Harbors Potentially Co-Druggable Targets for Multimodal Precision Therapy in Head and Neck Squamous Cell Carcinoma

The ErbB lineage of oncogenic receptor tyrosine kinases is frequently overexpressed in head and neck squamous cell carcinomas. A common co-regulon triggered by the ErbB proteins; involving shared signaling circuitries; may harbor co-druggable targets or response biomarkers for potential future multimodal precision therapy in ErbB-driven head and neck squamous cell carcinoma. We here present a cohort-based; genome-wide analysis of 488 head and neck squamous cell carcinomas curated as part of The Cancer Genome Atlas Project to characterize genes that are significantly positively co-regulated with the four ErbB proteins and those that are shared among all ErbBs denoting a common ErbB co-regulon. Significant positive gene correlations involved hundreds of genes that were co-expressed with the four ErbB family members (q < 0.05). A common; overlapping co-regulon consisted of a core set of 268 genes that were uniformly co-regulated with all four ErbB genes and highly enriched for functions in chromatin organization and histone modifications. This high-priority set of genes contained ten putative antineoplastic drug-gene interactions. The nature and directionality of these ten drug-gene associations was an inhibiting interaction for seven (PIK3CB; PIK3C2B; HDAC4; FRK; PRKCE; EPHA4; and DYRK1A) of them in which the drug decreases the biological activity or expression of the gene target. For three (CHD4; ARID1A; and PBRM1) of the associations; the directionality of the interaction was such that the gene predicted sensitivit y to the drug suggesting utility as potential response biomarkers. Drug-gene interactions that predicted the gene product to be reduced by the drug included a variety of potential targeted molecular agent classes. This unbiased genome-wide analysis identified a target-rich environment for multimodal therapeutic approaches in tumors that are putatively ErbB-driven. The results of this study require preclinical validation before ultimately devising lines of combinatorial treatment strategies for ErbB-dependent head and neck squamous cell carcinomas that incorporate these findings.

Determining the molecular landscape and impact on prognosis in HPV-associated head and neck cancer

BACKGROUND

Human papillomavirus (HPV) associated head and neck squamous cell carcinoma (HNSCC) has a better prognosis than HNSCC due to other risk factors. However, there is significant heterogeneity within HPV-associated HNSCC and 25% of these patients still do poorly despite receiving aggressive therapy. We currently have no good molecular tools to differentiate and exclude this "high-risk" sub-population and focus on "low-risk" patients for clinical trials. This has been a potential barrier to identifying successful de-escalation treatment strategies in HPV-associated HNSCC. We conducted an analysis of molecular markers with a well-known role in the pathogenesis of HPV-associated HNSCC and hypothesized that these markers could help independently predict recurrence and prognosis in these patients and therefore help identify at the molecular level "low-risk" patients suitable for de-escalation trials.

METHODS

We analyzed 24 tumor specimens of patients with p16+ HNSCC who underwent definitive resection as primary treatment. Tissue microarray (TMA) was generated from the 24 pathology blocks and immunohistochemistry (IHC) was performed using highly specific antibodies for our chosen biomarkers (PI3K-PTEN, AKT pathway, mTOR, 4EBP1, S6, and pAMPK, ERCC-1). Transcriptome data was also obtained for 7 p16+ HNSCC patients from The Cancer Genome Atlas (TCGA). Data from the TMA and TCGA were analyzed for association of relapse-free survival (RFS) and overall survival (OS) with protein and gene expression of the chosen biomarkers.

RESULTS

Increased pAMPK protein activity by IHC and AMPK gene expression by TCGA gene expression data was correlated with improved RFS with a trend towards statistical significance.

CONCLUSIONS

This data suggests that increased pAMPK activity and expression may portend a better prognosis in HPV-associated HNSCC undergoing primary definitive resection. However, these findings require validation in larger studies.

Association of Nonsteroidal Anti-inflammatory Drug Use With Survival in Patients With Squamous Cell Carcinoma of the Head and Neck Treated With Chemoradiation Therapy

IMPORTANCE

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, are commonly prescribed medications with anti-inflammatory and antiplatelet properties used long term to decrease the risk of cardiovascular events. A recent study showed that aspirin was associated with improved survival in patients with head and neck squamous cell carcinoma (HNSCC) who were treated with surgery.

OBJECTIVE

To examine whether use of NSAIDs during definitive chemoradiation therapy (CRT) was associated with improved outcomes in patients with HNSCC.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study analyzed patients with HNSCC who were treated with CRT at a single institution between January 1, 2005, and August 1, 2017. Patient and tumor characteristics included age, race/ethnicity, smoking status, alcohol use, comorbidities (respiratory, cardiovascular, immune, renal, endocrine), disease stage, human papillomavirus status, and treatment duration. Data were analyzed from May 1, 2019, to March 17, 2020.

EXPOSURES

Patients were dichotomized by NSAID use during treatment.

MAIN OUTCOMES AND MEASURES

The association of NSAID use with patterns of failure, disease-specific survival (DSS), and overall survival (OS) was examined using multivariate Cox proportional hazard regression models. Survival estimates for OS and DSS were generated using Kaplan-Meier survival curves.

RESULTS

A total of 460 patients (median [interquartile range] age, 60 [53.9-65.6] years; 377 [82.0%] men) were included in the analysis. Among these patients, 201 (43.7%) were taking NSAIDs during treatment. On univariate analysis, NSAID use (hazard ratio [HR], 0.63; 95% CI, 0.43-0.92; P = .02) was associated with better OS. On Cox regression analysis, after backward selection adjustment for potentially confounding factors (age, smoking status, primary tumor site, human papillomavirus status, diabetes, stroke, hyperlipidemia), NSAID use remained significantly associated with better OS (HR, 0.59; 95% CI, 0.38-0.90; P = .02). NSAID use was associated with significantly better OS at 5 years compared with patients who did not take concurrent NSAIDs (63.6% [56 of 88 patients]; 95% CI, 58%-73% vs 56.1% [83 of 148 patients]; 95% CI, 50%-63%; P = .03). NSAID use was not associated with better DSS in univariate (HR, 0.82; 95% CI, 0.48-1.41; P = .47) or multivariate (HR, 0.98; 95% CI, 0.57-1.70; P = .44) analysis. NSAID use was not associated with better response to treatment (HR, 1.44; 95% CI, 0.91-2.27; P = .12) or distant failure (HR, 1.12; 95% CI, 0.68-1.84; P = .65). Change in local control with NSAID use was not statistically significant (HR, 0.59; 95% CI, 0.31-1.10; P = .10).

CONCLUSIONS AND RELEVANCE

This cohort study suggests a possible OS advantage for patients taking NSAIDs during chemoradiation for HNSCC. Further studies examining this association are warranted.

Prognostic significance of MTOR expression in HPV positive and negative head and neck cancers treated by chemoradiation

BACKGROUND

The mechanistic target of rapamycin (MTOR) plays a key role in regulating cell growth and metabolism and is commonly overexpressed in head and neck cancer (HNSCC). This study investigated the association of MTOR with clinical outcome in human papilloma virus (HPV) positive and negative HNSCC patients treated by chemoradiation.

METHODS

A tissue microarray (TMA) consisting of cores from 109 HNSCC patients treated by definitive chemoradiation was constructed and stained with antibodies against p16 and MTOR and expression correlated with clinicopathological features and clinical outcome.

RESULTS

MTOR varied widely between tumor cores and was not associated with HPV status or clinicopathological features. There was a positive correlation with pre-treatment FDG uptake. (P = .01). In HPV negative patients, MTOR predicted for shorter locoregional control (P = .02), diseases free survival (P = .02), and overall survival (P = .04). MTOR expression was not associated with outcome in HPV positive patients.

CONCLUSIONS

Prognostic significance of MTOR expression depends on HPV status.