Significance of p16 expression in head and neck cancer patients treated with radiotherapy and cetuximab

Estimating Impacts of p16 Status on Tumor Radiosensitivity in Head and Neck Cancer using Predictive Models

The intrinsic radiosensitivity index (RSI) and genomic-adjusted radiation dose (GARD) were reported to be able to predict the surviving fraction at 2 Gy and therapeutic effect when delivering actual treatment doses using the gene expression profiles of clinical cases. Given the impact of p16 status, a surrogate marker of the human papillomavirus (HPV) infection, on radiosensitivity, we attempted to apply the RSI and GARD to estimate p16-associated radiosensitivity in head and neck squamous cell carcinoma (HNSC). For this purpose, The Cancer Genome Atlas (TCGA) dataset was employed. In the GARD calculation, we assumed that p16-positive patients received 60 Gy in 30 fractions, while p16-negative patients received 70 Gy in 35 fractions. p16 positivity was associated with favorable characteristics compared to negative patients. The RSI and GARD analyses demonstrated increased radiosensitivity and high therapeutic effect in p16-positive patients, compared to p16-negative patients. Additionally, tumor microenvironmental conditions predicted by other models were also significantly affected by p16 status. Collectively, the models used in this study could be a promising tool for estimating p16-associated radiosensitivity in HNSC.

A Survey of Human Papillomavirus and Epstein-Barr virus Immunohistochemical Status in Patients with Head and Neck Squamous Cell Carcinoma (HNSCC)

BACKGROUND

Head and neck cancers are among the most prevalent cancers in the body. The aim of this study was to evaluate the expression of P16 and Epstein-Barr virus/latent membrane protein (EBV/LMP1) markers by immunohistochemistry in patients with squamous cell carcinoma of the head and neck.

METHODS

In this study, all tissue samples of head and neck biopsies from 75 patients with confirmed diagnosis of squamous cell carcinoma (HNSCC) during 2016 to 2018 who admitted to the pathology laboratory of Imam Khomeini Hospital, Iran were selected. Paraffin blocks which prepared from these tissue samples were obtained. The slides were prepared from all samples for routine Hematoxylin-Eosin and immunohistochemical staining to evaluate the expression of EBV/LMP1 and P16 markers in cancer cells.

RESULTS

The mean age of patients was 63 years and most patients (85.3%) were male in 75 patients with HNSCC. There was a significant relationship between EBV/LMP1 biomarker expression and vascular invasion in patients (p < 0.05). There was no relationship between EBV/LMP1 biomarker expression and age, sex ,anatomical site of tumor and tumor differentiation of patients (p > 0.05). There was no relationship between P16 biomarker expression and age, sex, tumor differentiation, anatomical site of tumor and vascular invasion of patients (p > 0.05). There is a significant relationship between P16 biomarker and EBV/LMP1 biomarker staining (p < 0.05).

CONCLUSION

The level of P16 positive biomarker was high in patients with HNSCC. However, the EBV/LMP1 positive biomarker was moderate in patients. There was a relationship between EBV/LMP1 biomarker expression and vascular invasion in HNSCC patients, as well as between P16 biomarker and EBV/LMP1 biomarker staining.

Long-term recurrence-free survival after an unplanned reduction in radiotherapy for HPV-positive oropharyngeal SCC: Two cases and a review of the literature

There is currently no clear distinction between the treatment of HPV-positive and HPV-negative oropharyngeal squamous cell carcinoma (OPSCC). HPV-positive OPSCC has been demonstrated to be more radiosensitive than its HPV-negative counterpart. Despite this, patients with HPV-positive OPSCC continue to receive a full dose of radiation (70 Gy) outside clinical trials. However, this high dose comes with considerable morbidities, including severe mucositis, dysphagia, and xerostomia. We describe the cases of 2 patients with HPV-positive OPSCC who received two cycles of high-dose cisplatin at 100 mg/m² on 3 separate days, along with concurrent radiotherapy at 50 Gy in 25 fractions for one and 46 Gy in 23 fractions for the other. During treatment, both patients experienced significant acute-phase toxicities-including grade 3 mucositis, grade 3 nausea, and grade 2 dermatitis-and their treatment regimen was stopped before its planned completion. Nevertheless, after a follow-up of 75 and 78 months, respectively, neither patient exhibited any evidence of disease. Late toxicities included grade 1 xerostomia, grade 1 pharyngeal-phase dysphagia, and grade 1 dysgeusia with some foods. We conclude that de-escalating the dose of radiation for HPV-positive patients by 30% and identifying which patients can safely be treated with this level of dose reduction warrants further study.

Targeting the AKT pathway: Repositioning HIV protease inhibitors as radiosensitizers

Cellular resistance in tumour cells to different therapeutic approaches has been a limiting factor in the curative treatment of cancer. Resistance to therapeutic radiation is a common phenomenon which significantly reduces treatment options and impacts survival. One of the mechanisms of acquiring resistance to ionizing radiation is the overexpression or activation of various oncogenes like the EGFR (epidermal growth factor receptor), RAS (rat sarcoma) oncogene or loss of PTEN (phosphatase and tensin homologue) which in turn activates the phosphatidyl inositol 3-kinase/protein kinase B (PI3-K)/AKT pathway responsible for radiation resistance in various tumours. Blocking the pathway enhances the radiation response both in vitro and in vivo. Due to the differential activation of this pathway (constitutively activated in tumour cells and not in the normal host cells), it is an excellent candidate target for molecular targeted therapy to enhance radiation sensitivity. In this regard, HIV protease inhibitors (HPIs) known to interfere with PI3-K/AKT signaling in tumour cells, have been shown to sensitize various tumour cells to radiation both in vitro and in vivo. As a result, HPIs are now being investigated as possible radiosensitizers along with various chemotherapeutic drugs. This review describes the mechanisms by which PI3-K/AKT pathway causes radioresistance and the role of HIV protease inhibitors especially nelfinavir as a potential candidate drug to target the AKT pathway for overcoming radioresistance and its use in various clinical trials for different malignancies.

Combined p16 and p53 expression in cervical cancer of unknown primary and other prognostic parameters : A single-center analysis

BACKGROUND AND PURPOSE

Cervical cancer of unknown primary (CUP) represents an uncommon and heterogeneous subentity of head and neck cancer. However, both optimal diagnostics and therapy remain unclear. An improved understanding of the underlying pathology is essential to enable future tailored therapies and optimized outcomes.

MATERIALS AND METHODS

We retrospectively analyzed 53 patients with head and neck CUP and 48 available cervical lymph node specimens. All patients have received radiotherapy between 2007 and 2015. Preradiotherapy involved lymph node specimens were analyzed for p16 and p53 immunoreactivity. The prognostic relevance of the combined p16 and p53 status and other clinical parameters were examined by univariate and multivariate analyses.

RESULTS

Median patient age was 61.5 years and median irradiation dose to the involved nodal levels was 66 Gy. Of the 48 evaluated specimens, 13 (27%) were p16-positive and 31 (64.6%) p53-positive. After a median follow up of 32.9 months, patients with p16-negative and simultaneously p53-positive tumors showed a significantly inferior tumor-specific survival (TSS) compared to those with either p16+/p53-, p16+/p53+, or p16-/p53- (univariate: p = 0.055, multivariate: p = 0.038). Other factors with an adverse impact on TSS in the univariate analysis were smoking history (p = 0.032) and nodal stage (p = 0.038).

CONCLUSIONS

The combined p16- and p53-expression status in cervical metastases of CUP may represent a simple method for risk stratification. Further validation of these biomarkers in large prospective trials is essential to design rational trials for CUP treatment optimization.

Impact of Sonic Hedgehog Pathway Expression on Outcome in HPV Negative Head and Neck Carcinoma Patients after Surgery and Adjuvant Radiotherapy

INTRODUCTION

HPV positive patients suffering from head and neck cancer benefit from intensified radiotherapy when applied as a primary as well as an adjuvant treatment strategy. However, HPV negative patients treated with surgery and adjuvant radiotherapy lack validated prognostic biomarkers. It is therefore important to define prognostic biomarkers in this particular patient population. Especially, ´high-risk groups´ need to be defined in order to adapt treatment protocols. Since dysregulation of the sonic hedgehog pathway plays an important role in carcinogenesis, we aimed to assess whether members of the sonic hedgehog-signaling pathway may act as prognostic factors in patients with HPV negative head and neck squamous cell carcinoma.

MATERIALS AND METHODS

In this prospective study, pretreatment tumor biopsies of patients with head and neck squamous cell carcinoma were taken during panendoscopy (2005 to 2008). All patients were treated with surgery and postoperative radiotherapy. After assessment of HPV and p16 status, protein expression profiles of the Sonic hedgehog-signaling pathway were determined by immunohistochemistry and tissue microarray analyses in 36 HPV negative tumor biopsies. Expression profiles of Sonic hedgehog, Indian hedgehog, Patched, Smoothened, Gli-1, Gli-2 and Gli-3 were correlated with patients´ clinical data, local-control rate, disease-free as well as overall survival. Data from The Cancer Genome Atlas databank were used for external validation of our results.

RESULTS

Gli-1 (p = 0.04) and Gli-2 (p = 0.02) overexpression was significantly linked to improved overall survival of HPV negative patients. Gli-2 (p = 0.04) overexpression correlated significantly with prolonged disease-free survival. Cox-multivariate analysis showed that overexpression of Gli-2 correlated independently (HR 0.40, 95% CI 0.16-0.95, p = 0.03) with increased overall survival.

DISCUSSION

Gli-1 and Gli-2 overexpression represents a substantial prognostic factor for overall and disease-free survival in patients with locally advanced HPV negative head and neck cancer undergoing surgery and postoperative radiotherapy.

Radio-Immunotherapy-Induced Immunogenic Cancer Cells as Basis for Induction of Systemic Anti-Tumor Immune Responses - Pre-Clinical Evidence and Ongoing Clinical Applications

Radiotherapy (RT) primarily aims to locally destroy the tumor via the induction of DNA damage in the tumor cells. However, the so-called abscopal, namely systemic and immune–mediated, effects of RT move over more and more in the focus of scientists and clinicians since combinations of local irradiation with immune therapy have been demonstrated to induce anti-tumor immunity. We here summarize changes of the phenotype and microenvironment of tumor cells after exposure to irradiation, chemotherapeutic agents, and immune modulating agents rendering the tumor more immunogenic. The impact of therapy-modified tumor cells and damage-associated molecular patterns on local and systemic control of the primary tumor, recurrent tumors, and metastases will be outlined. Finally, clinical studies affirming the bench-side findings of interactions and synergies of radiation therapy and immunotherapy will be discussed. Focus is set on combination of radio(chemo)therapy (RCT) with immune checkpoint inhibitors, growth factor inhibitors, and chimeric antigen receptor T-cell therapy. Well-deliberated combination of RCT with selected immune therapies and growth factor inhibitors bear the great potential to further improve anti-cancer therapies.

The rationale for HPV-related oropharyngeal cancer de-escalation treatment strategies

The treatment paradigms for head and neck squamous cell cancer (HNSCC) are changing due to the emergence of human papillomavirus-associated tumors (HPV-related), possessing distinct molecular profiles and responses to therapy. Retrospective studies have suggested that HPV-related HNSCCs are more frequently cured than those caused by tobacco. Current clinical trials focus on the reduction of treatment-related toxicity and the development of HPV-targeted therapies. New treatment strategies include: 1) dose reduction of radiotherapy, 2) the use of cetuximab instead of cisplatin for chemo-radiation 3) less invasive surgical options, i.e. trans-oral robotic surgery and trans-oral laser microlaryngoscopy, and 4) more specific treatment attempts, including immunotherapeutic strategies, thanks to increasing comprehension of the molecular background of HPV-related HNSCC. Whereas recently published data shed light on immune mechanisms, other studies have focused on specific vaccination against HPV-related HNSCC. A crucial problem is patient selection to the chosen bias. Truly HPV-related cancers (p16-positive and HPV DNA-positive) with biomarkers for good response to therapy could be included in randomized trials aiming for less severe and better tailored therapy.

HPV-Positive Oropharyngeal Carcinoma

Objective

Human papillomavirus-positive (HPV+) head and neck squamous cell carcinoma is increasing in incidence and appears to exhibit improved response to treatment and better survival than that of HPV– head and neck squamous cell carcinoma. The purpose of this systematic review was to examine the current literature regarding treatment and prognosis of HPV+ oropharyngeal squamous cell carcinoma (OPSCC) and identify whether type of treatment (primarily surgery vs primarily radiation) significantly affects survival rates.

Data Sources

PubMed and Cochrane Library databases.

Review Methods

A computerized search of the PubMed and Cochrane Library databases was performed to identify English-language articles published between January 1, 2000, and October 21, 2014. Studies were included only if they were prospective or retrospective observational series of OPSCC patients that reported HPV status, treatment regimen, and survival outcomes. Outcomes were determined for HPV+ and HPV– OPSCC patients, with subanalyses according to the type of treatment received.

Results

Fifty-six articles were eligible for this review. In the HPV+ analysis, the unadjusted hazard rate ratio (HR) for surgery vs radiation treatment was 1.33 ( P = .114). Nine confounders were considered, and HRs were adjusted for each covariate. While HRs were almost all >1 for all covariates, none of the HRs was statistically significant at P < .05. The HR for HPV– OPSCC was higher for radiation than surgery.

Conclusions

HPV+ OPSCC has an improved prognosis and lower rates of adverse events when compared with HPV– OPSCC. HPV– OPSCC had significantly worse outcomes when treated with primary radiation as compared with primary surgery. There was no statistically significant difference in HRs for HPV+ OPSCC with primary radiation vs primary surgery treatment.

Primary radiotherapy or postoperative radiotherapy in patients with head and neck cancer: Comparative analysis of inflammation-based prognostic scoring systems

INTRODUCTION

Inflammation-based scoring systems have potential value in evaluating the prognosis of cancer patients; however, detailed comparative analyses in well-characterized head and neck cancer patient collectives are missing.

METHODS

We analyzed overall survival (OS) in locally advanced head and neck cancer patients who were treated with curative intent by primary radiotherapy (RT) alone, by RT in combination with cetuximab (RIT) or with cisplatin (RCHT), and by primary surgery followed by postoperative radiotherapy (PORT). The primary RT collective (N = 170) was analyzed separately from the surgery plus RT group (N = 148). OS was estimated using the Kaplan-Meyer method. Cox proportional-hazard regression models were applied to compare the risk of death among patients stratified according to risk factors and the inflammation-based Glasgow Prognostic Score (GPS), the modified GPS (mGPS), the neutrophil-lymphocyte ratio (NLR), the platelet-lymphocyte ratio (PLR), and the prognostic index (PI).

RESULTS

A prognostic relevance of the scoring systems for OS was observed in the primarily irradiated, but not in the PORT collective. OS was 35.5, 18.8, and 15.4 months, respectively, according to GPS 0, 1, and 2. OS according to mGPS 0-2 was identical. The PLR scoring system was not of prognostic relevance, while OS was 27.3 months in the NLR 0 group and 17.3 months in the NLR 1 group. OS was 35.5 months in PI 0, 16.1 months in PI 1, and 22.6 months in PI 2.

CONCLUSION

GPS/mGPS scoring systems are able to discriminate between three risk groups in primarily, but not postoperatively irradiated locally advanced head and neck cancer patients.

Improved survival in HPV/p16-positive oropharyngeal cancer patients treated with postoperative radiotherapy

INTRODUCTION

In the literature, HPV infection and/or p16 positivity have been consistently demonstrated to correlate with improved response rates in oropharyngeal squamous cell carcinoma (OPSCC) patients treated with primary radiotherapy (RT) alone and in combination with chemotherapy. However, the exact role of HPV/p16 positivity in patients treated with postoperative RT is still unclear.

METHODS

We analyzed tumor samples for HPV-DNA and p16 expression and correlated these variables with treatment outcome in a series of 63 consecutively treated oropharyngeal cancer patients (95% stage III/IV). HPV and p16 analysis were performed using validated test systems. Survival was estimated by the Kaplan-Meier method. Cox proportional hazard regression models were applied to compare the risk of death among patients stratified according to risk factors.

RESULTS

Expression of p16 or high-risk HPV-DNA was detected in 60.3% and 39.6% of the tumors, respectively. p16 expression [overall survival (OS) at 2 years: 91%] as well as HPV infection (OS at 2 years: 95%) was associated with improved OS. Mean survival in p16-positive patients was 112 months compared to 64.6 months in case of p16 negativity. All HPV-positive tumors stained positive for p16. In a multivariable analysis, p16 positivity was associated with improved OS and with disease-free survival.

CONCLUSION

p16 expression and HPV infection are strongly associated with the outcome of postoperatively irradiated OPSCC patients. HPV and p16 double-negative OPSCC patients should be regarded as a distinct "very high-risk patient group" that may benefit from intensified or novel treatment combinations.