Intensity-modulated radiation therapy as primary treatment for oropharyngeal squamous cell carcinoma

Revalidation of Proactive Gastrostomy Tube Placement Guidelines for Head and Neck Cancer Patients Receiving Helical Intensity-Modulated Radiotherapy

The Royal Brisbane and Women's Hospital (RBWH) Swallowing and Nutrition Management Guidelines for Patients with Head and Neck Cancer were developed to enable evidence-based decision-making by the Head and Neck Multidisciplinary Team (H&N MDT) regarding enteral nutrition support options. The purpose of this study was to revalidate these guidelines in a cohort of patients receiving helical intensity-modulated radiotherapy (H-IMRT) compared to a historical cohort who received primarily 3D-conformal radiotherapy. Eligible patients attending the RBWH H&N MDT between 2013 and 2014 (n = 315) were assessed by the guidelines, with high-risk patients being recommended proactive gastrostomy tube placement. Data were collected on guideline adherence, gastrostomy tube insertions, the duration of enteral tube use and weight change. Sensitivity, specificity and positive predictive and negative predictive values were calculated and compared with the historical cohort. Overall guideline adherence was 84%, with 60% and 96% adherence to the high-risk and low-risk pathways, respectively. Seventy patients underwent proactive gastrostomy tube placement (n = 62 high-risk; n = 8 low-risk). Validation outcomes were sensitivity 73% (compared to 72%) and specificity 86% (compared to 96%). The guidelines yielded a high sensitivity and specificity, remaining valid in a cohort of patients treated with H-IMRT. Further studies are recommended to improve the sensitivity and understand the decrease in specificity in order to make ongoing guideline improvements.

Nutrition outcomes and treatment toxicities in patients with head and neck cancer receiving helical intensity-modulated radiotherapy

BACKGROUND

Helical intensity-modulated radiotherapy (H-IMRT) provides excellent limitation of dose to tissues not requiring treatment, although acute toxicity still occurs. The present study aimed to determine how treatment-related acute toxicities affect nutrition outcomes in patients with head and neck cancer.

METHODS

A prospective observational study was conducted in 194 patients undergoing curative intent H-IMRT with or without other treatment modalities. Weight outcomes (kg) and acute toxicity and dysphagia data were collected during treatment using Common Toxicity Criteria for Adverse Effects (CTCAE), version 4.0.

RESULTS

Significant weight loss (> 10%) was observed in 30% of high nutritional risk patients and 7% of low nutritional risk patients. Nausea, adjusted for baseline dysphagia, in high nutritional risk patients and nausea, dysphagia and pharyngeal mucositis in low nutritional risk patients were significant factors in explaining the percentage loss in baseline weight to treatment completion.

CONCLUSIONS

Significant weight loss remains an issue during treatment, despite improvements in radiotherapy technology and high-level multidisciplinary care.

De-escalation studies in HPV-positive oropharyngeal cancer: How should we proceed?

Human papilloma virus (HPV) is a well-established causative factor in a subset of squamous cell carcinomas of the head and neck (HNSCC). Although HPV can be detected in various anatomical subsites, HPV-positive oropharyngeal squamous cell carcinoma (OPSCC) is the most common HPV-related malignancy of the head and neck, and its worldwide incidence is constantly rising. Patients with OPSCC are generally younger, have less co-morbidities and generally have better prognosis due to different biological mechanisms of carcinogenesis. These facts have generated hypotheses on potential treatment modifications, aiming to minimize treatment-related toxicities without compromising therapy efficacy. Numerous randomized clinical trials have been designed to verify this strategy and increasingly real-world evidence data from retrospective, observational studies is becoming available. Until now, the data do not support any modification in contemporary treatment protocols. In this narrative review, we outline recent data provided by both randomized controlled trials and real-world evidence of HPV-positive OPSCC in terms of clinical value. We critically analyze the potential value and drawbacks of the available data and highlight future research directions. This article was written by members and invitees of the International Head and Neck Scientific Group.(www.IHNSG.com).

Outcomes after primary intensity-modulated radiation therapy for oropharyngeal squamous cell carcinoma at a New Zealand regional cancer centre: Impact of p16 status

INTRODUCTION

The rising incidence of oropharyngeal squamous cell carcinoma (OPSCC) in New Zealand is due to an increase in the numbers of human papilloma virus (HPV)-associated OPSCC. We evaluated the impact of positive p16 immunohistochemistry, as a surrogate for HPV positivity, on OPSCC outcomes after primary intensity-modulated radiotherapy (IMRT) with or without concurrent chemotherapy.

METHODS

Retrospective review was undertaken of electronic medical records of 90 patients with OPSCC who received primary IMRT with or without chemotherapy between 2008 and mid-2015 at the Regional Cancer Centre, Waikato Hospital, Hamilton, New Zealand.

RESULTS

Median age was 57.5 years. Immunohistochemistry for p16 was positive in 53 (59%) OPSCC while 37 (41%) had negative or unknown p16 status. Median radiotherapy dose was 70 Gy. Chemotherapy was administered to 78 (87%) patients, most receiving high-dose cisplatin. Nine patients had residual disease following treatment completion. Seven patients relapsed, and 26 died during the study period. Five patients with p16-positive OPSCC had persistent or recurrent disease. Actuarial 3-year locoregional control, disease-free survival, and overall survival for all patients were 80.7%, 74.7%, and 77.1%, respectively. Among p16-positive OPSCC patients, 3-year locoregional control, disease-free survival, and overall survival were 89.5%, 80.8%, and 90.9%, respectively.

CONCLUSION

Outcomes after IMRT for OPSCC at Waikato Hospital are in line with the reported literature. Human papilloma virus-related OPSCC has better outcomes compared with patients with unknown or HPV-unrelated OPSCC. Trials are underway evaluating reduced intensity of treatment for HPV-related OPSCC.

Outcomes utilizing intensity-modulated radiotherapy in oropharyngeal cancers: Tonsils versus base of tongue

BACKGROUND

The purpose of this study was to present the outcomes of oropharyngeal cancers treated with intensity-modulated radiotherapy (IMRT) especially the differences between tonsillar and base of tongue (BOT) primaries.

METHODS

Retrospective analysis of 124 patients with biopsy proven squamous cell carcinomas of the oropharynx, treated with IMRT.

RESULTS

Human papillomavirus (HPV) association correlated with improvement in survivals in both tonsillar and BOT primaries. At the 2-year median follow-up, the cumulative incidences of locoregional recurrences were 8% in both the tonsil and BOT groups (P = .76) but the distant metastases were 8% in the tonsil group versus 26% in the BOT group (P = .009). Thirty percent of tonsil primaries has ≥N2c neck disease as compared to 54% of BOT. Incidence of distant metastases increases with advanced nodal classification, especially >N2c.

CONCLUSION

Even though the locoregional controls are excellent with IMRT and chemotherapy, these patients continue to fail distantly, particularly significant for the BOT group and for nodal stage >N2c.

Primary surgical management with radial forearm free flap reconstruction in T4 oropharyngeal cancer: Complications and functional outcomes

PURPOSE

Functional outcomes and complication rates after open surgery for advanced-stage oropharyngeal cancers are rarely reported. These measures are critical for choice of treatment modality and patient counseling. We describe the long term functional outcomes and associated complications of primary surgical management of T4 oropharyngeal cancers reconstructed with radial forearm free flaps.

MATERIALS AND METHODS

A retrospective review was performed of 40 patients with T4 oropharyngeal cancers treated between 2005 and 2015 at a tertiary care center.

RESULTS

Forty patients with T4 oropharyngeal cancers underwent open surgical resection and radial forearm free flap reconstruction at the time of surgery. Mandibulotomy was required in 33 (82.5%) cases. Thirty-five (87.5%) patients received adjuvant radiation or combined chemotherapy and radiation. Tracheostomy was performed in all patients, but every patient was eventually decannulated. Twenty (57.1%) patients required gastrostomy tube placement at some point during treatment; however, 91.4% were on a completely oral diet with a mean FOSS score of 1.6 by 1year after completion of treatment. The addition of adjuvant treatment was the only factor significantly associated with poorer FOSS scores. The overall rates of short and long-term complications were 60.0% and 57.1% respectively. The most common short and long-term complications were infection (30.0%) and velopharyngeal insufficiency (25.7%) respectively.

CONCLUSIONS

Traditional open surgical approaches to large tumors of the oropharynx carry higher complication rates than more recent advanced transoral approaches. However, they can still be utilized with excellent long-term functional results in certain cases of advance oropharyngeal cancers not amenable to transoral approaches. With careful reconstruction of oropharyngeal defects, over 90% of patients can achieve a completely oral diet.

Incidence and survival of oropharyngeal cancer in Denmark: a nation-wide, population-based study from 1980 to 2014

BACKGROUND

Oropharyngeal carcinomas (OPCs) constitute a significant and increasing proportion of head and neck carcinomas and are an important global cause of morbidity and mortality. The purpose of this study was to determine trends in incidence and survival in OPC in the Danish population from 1980 to 2014.

METHODS

This study included all patients registered in the nationwide Danish Cancer Registry over the period 1980-2014. The age-adjusted incidence rates (AAIR) per 100,000, annual percentage change (APC) and average annual percent change (AAPC) were evaluated. Five-year relative survival (RS) was calculated with Cox regression analyses in relation to gender, anatomical location and histology.

RESULTS

A total of 6555 patients (69% male) were included, with a median age at diagnosis of 60 years. The AAIR of patients with OPC increased from 0.815 per 100,000 in 1980 to 4.51 per 100,000 in 2014 with an AAPC of 5.3. The 5-year RS increased significantly from 33.1% over the period 1980-1984 to 58.5% (25.4% points) over the period 2010-2014. With no significant difference stratified for gender. Tumors located at the palatine tonsils (n = 3333) and salivary gland OPC (n = 90) had significantly better survival compared with other sub-locations and histology subtypes. In the APC model the birth cohort effect rate ratio increased until 1925 and then decreased until 1935 from which point it increased in the last cohorts.

CONCLUSIONS

In this population-based study, we observed a significant increase in the incidence of OPCs and in the RS for OPC. We also identified a profound birth cohort effect on the incidence.

American Brachytherapy Society Task Group Report: Combined external beam irradiation and interstitial brachytherapy for base of tongue tumors and other head and neck sites in the era of new technologies

Irradiation plays an important role in the treatment of cancers of the head and neck providing a high locoregional tumor control and preservation of organ functions. External beam irradiation (EBI) results in unnecessary radiation exposure of the surrounding normal tissues increasing the incidence of side effects (xerostomy, osteoradionecrosis, and so forth). Brachytherapy (BT) seems to be the best choice for dose escalation over a short treatment period and for minimizing radiation-related normal tissue damage due to the rapid dose falloff around the source. Low-dose-rate BT is being increasingly replaced by pulsed-dose-rate and high-dose-rate BT because the stepping source technology offers the advantage of optimizing dose distribution by varying dwell times. Pulsed-dose and high-dose rates appear to yield local control and complication rates equivalent to those of low-dose rate. BT may be applied alone; but in case of high risk of nodal metastases, it is used together with EBI. This review presents the results and the indications of combined BT and EBI in carcinoma of the base of tongue and other sites of the head and neck region, as well as the role BT plays among other-normal tissue protecting-modern radiotherapy modalities (intensity-modulated radiotherapy, stereotactic radiotherapy) applied in these localizations.

(18)F-FDG PET/CT to assess response and guide risk-stratified follow-up after chemoradiotherapy for oropharyngeal squamous cell carcinoma

PURPOSE

To evaluate the use of (18)F-FDG PET/CT as the principal investigation to assess tumour response, to determine the need for further surgery and to guide follow-up following radical chemoradiotherapy for stage III/IV oropharyngeal squamous cell carcinoma (OPSCC).

METHODS

A retrospective analysis was undertaken in 146 patients treated at our centre with radical chemoradiotherapy for OPSCC and who had a PET/CT scan to assess response. According to the PET/CT findings, patients were divided into four groups and recommendations: (1) complete metabolic response (enter clinical follow-up); (2) low-level uptake only (follow-up PET/CT scan in 12 weeks); (3) residual uptake suspicious for residual disease (further investigation with or without neck dissection); and (4) new diagnosis of distant metastatic disease (palliative treatment options).

RESULTS

The initial PET/CT scan was performed at a median of 12.4 weeks (range 4.3 - 21.7 weeks) following treatment. Overall sensitivity and specificity rates were 92.0 % (74.0 - 99.0 %) and 85 % (77.5 - 90.9 %). Of the 146 patients, 90 (62 %) had a complete response and had estimated 3-year overall and disease-free survival rates of 91.9 % (85.6 - 98.2 %) and 85.6 % (78.0 - 93.2 %), respectively, 17 (12 %) had residual low-level uptake only (with two having confirmed residual disease on subsequent PET/CT, both surgically salvaged), 30 (21 %) had suspicious residual uptake (12 proceeded to neck dissection; true positive rate at surgery 33 %). HPV-positive patients with reassuring PET/CT findings had an estimated 3-year progression-free survival rate of 91.7 % (85.2 - 98.2 %), compared with 66.2 % (41.5 - 90.9 %) of HPV-negative patients.

CONCLUSION

A strategy of using PET/CT results alongside clinical examination to help select patients for salvage surgery appears successful. Despite a complete response on the 12-week PET/CT scan, HPV-negative patients have a significant risk of disease relapse in the following 2 years and further studies to assess whether surveillance imaging in this group could improve outcomes are warranted.

Intensity-modulated radiotherapy in the treatment of locoregionally advanced head and neck cancer: implementation and outcomes in a New Zealand community hospital

Introduction

Intensity‐modulated radiotherapy (IMRT) has become the standard of care for squamous cell cancer of the head and neck (HNSCC). This report presents early outcomes of IMRT with concomitant chemotherapy in a community setting in New Zealand.

Methods

Forty‐eight patients with stage III and IV advanced HNSCC received definitive treatment with IMRT. A dose of 66 Gy in 30 fractions was delivered over 6 weeks with 3‐weekly concurrent cisplatin after a single induction cycle of cisplatin and 5‐fluorouracil. Acute toxicity, locoregional control (LRC), disease‐free survival and overall survival (OS) outcomes were analysed.

Results

Follow‐up ranged from 2 to 82 months (median 34 months). Acute grade 2 toxicity was observed in 27 patients and grade 3 toxicity in 19 patients. No patients experienced grade 4 toxicity and there were no treatment‐related deaths. Locoregional failures occurred in six patients and distant metastatic disease occurred in five patients. Actuarial estimates of 3‐year LRC, disease‐free survival and OS were 87.3%, 74.4% and 73.7% respectively.

Conclusion

Definitive treatment of stage III and IV cancer of the head and neck with IMRT and concurrent chemotherapy was achievable in the community setting. Acute toxicities were manageable and 3‐year outcomes were comparable to other published series.

Surgical management of oropharyngeal squamous cell carcinoma: Survival and functional outcomes

BACKGROUND

The purpose of this study was to further define the impact of primary surgery in the management of oropharyngeal squamous cell carcinoma (SCC).

METHODS

Two hundred ninety-six patients with oropharyngeal SCC treated with primary surgery were included. Multivariable analysis and recursive partitioning analysis (RPA) identified predictors of survival and gastrostomy tube presence.

RESULTS

Multivariable analysis identified that HPV negativity (p = .0002), presence of extranodal extension (p = .0025), and advanced T classification (p = .0081) were independent predictors of survival. For HPV-positive patients, surgical approach (p = .0111) and margin status (p = .0287) were significant predictors of survival. For HPV-negative patients, extranodal extension (p = .0021) and advanced T classification (p = .0342) were significant predictors of survival. Smoking status and advanced neck disease did not impact survival, and the addition of adjuvant chemotherapy did not confer survival benefit in HPV-positive or HPV-negative subgroups.

CONCLUSION

Independent predictors of survival are unique in patients with oropharyngeal SCC treated with primary surgery. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1794-E1802, 2016.

Transoral robotic surgery vs. radiotherapy for management of oropharyngeal squamous cell carcinoma - A systematic review of the literature

BACKGROUND

Intensity-modulated radiation therapy (IMRT) with or without concurrent chemotherapy is widely utilized for the treatment of oropharyngeal squamous cell carcinoma (OPSCC). However, due to significant acute and late toxicities there has been increasing interest in minimally invasive surgical approaches, particularly transoral robotic surgery (TORS) in an attempt to preserve patient quality of life while maintaining oncologic outcomes. The aim of this study was to review the current literature in order to compare primary IMRT versus TORS in the management of OPSCC.

METHODS

A MEDLINE search was conducted to identify studies reporting on the outcomes of TORS or IMRT in the treatment of OPSCC. Reference lists were also reviewed for relevant articles. Oncologic, functional, and quality of life data is summarized and discussed.

RESULTS

One hundred-ninety papers were identified through the MEDLINE search. An additional 52 papers were retrieved by hand searching the reference lists. Ultimately, 44 papers were identified that discussed outcomes after IMRT or TORS for OPSCC. No outcomes from randomized trials were identified.

CONCLUSION

No randomized trials comparing TORS versus IMRT to each other were identified. Uncontrolled reports from the current literature suggest comparable oncologic outcomes with TORS compared to IMRT and functional outcomes may be superior. However, the median follow-up was relatively short and the TORS studies included patients with earlier stage OPSCC on average compared to IMRT studies. Prospective, randomized controlled trials and direct, well-matched comparisons are needed to further elucidate the role for TORS in the treatment of oropharyngeal squamous cell carcinoma.

Integrative analysis of the microRNA-mRNA response to radiochemotherapy in primary head and neck squamous cell carcinoma cells

Background

Head and neck squamous cell carcinoma (HNSCC) is a very heterogeneous disease resulting in huge differences in the treatment response. New individualized therapy strategies including molecular targeting might help to improve treatment success. In order to identify potential targets, we developed a HNSCC radiochemotherapy cell culture model of primary HNSCC cells derived from two different patients (HN1957 and HN2092) and applied an integrative microRNA (miRNA) and mRNA analysis in order to gain information on the biological networks and processes of the cellular therapy response. We further identified potential target genes of four therapy-responsive miRNAs detected previously in the circulation of HNSCC patients by pathway enrichment analysis.

Results

The two primary cell cultures differ in global copy number alterations and P53 mutational status, thus reflecting heterogeneity of HNSCC. However, they also share many copy number alterations and chromosomal rearrangements as well as deregulated therapy-responsive miRNAs and mRNAs. Accordingly, six common therapy-responsive pathways (direct P53 effectors, apoptotic execution phase, DNA damage/telomere stress induced senescence, cholesterol biosynthesis, unfolded protein response, dissolution of fibrin clot) were identified in both cell cultures based on deregulated mRNAs. However, inflammatory pathways represented an important part of the treatment response only in HN1957, pointing to differences in the treatment responses of the two primary cultures. Focused analysis of target genes of four therapy-responsive circulating miRNAs, identified in a previous study on HNSCC patients, revealed a major impact on the pathways direct P53 effectors, the E2F transcription factor network and pathways in cancer (mainly represented by the PTEN/AKT signaling pathway).

Conclusions

The integrative analysis combining miRNA expression, mRNA expression and the related cellular pathways revealed that the majority of radiochemotherapy-responsive pathways in primary HNSCC cells are related to cell cycle, proliferation, cell death and stress response (including inflammation). Despite the heterogeneity of HNSCC, the two primary cell cultures exhibited strong similarities in the treatment response. The findings of our study suggest potential therapeutic targets in the E2F transcription factor network and the PTEN/AKT signaling pathway.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1865-x) contains supplementary material, which is available to authorized users.

It is not just IMRT: Human papillomavirus related oropharynx squamous cell carcinoma is associated with better swallowing outcomes after definitive chemoradiotherapy

OBJECTIVES

Long term swallowing dysfunction in patients with oropharynx squamous cell carcinoma (OPSCC) treated with concurrent chemoradiation (CRT) is declining. While the use of intensity modulated radiotherapy (IMRT) is commonly believed to be a potential cause, we hypothesize that the increasing incidence of human papillomavirus (HPV) related disease may also favorably impact this outcome.

MATERIALS AND METHODS

We reviewed 130 HPV+ and 17 HPV- patients with stage III-IV OPSCC treated exclusively with conventional 3-field radiotherapy with chemotherapy between 2002 and 2010. The rates of normal diet, limited diet (significant restrictions in the types of foods eaten, and/or requiring nutritional supplementation for weight maintenance) and feeding tube dependence (FTD) were compared between HPV+ and HPV- patients. Cox proportional hazards modeling were used to perform univariate analysis (UVA) to examine predictors of a combined endpoint of dietary limitation, which included limited diet and/or FTD. These outcomes were also compared to our previously reported cohort of OPSCC patients treated between 1989 and 2002 to assess changes in toxicity over time given the changing disease epidemiology, in the setting of identical treatment regimens.

RESULTS

With a median follow-up of 55 months, HPV+ patients more frequently had resumed a normal diet (87% vs. 65%) at last follow up and had lower rates of limited diet (9% vs. 18%) and FTD (4% vs. 18%) compared to HPV- patients (p=0.02). HPV status was the only significant predictor of reduced swallowing dysfunction on UVA (HR 0.19; p=0.008). When compared to our 1989-2002 cohort, patients treated between 2002 and 2010 had less FTD (7.5% vs. 34%, p<0.001) and dietary limitations (26% vs.46%, p<0.001) at 6 months post treatment.

CONCLUSIONS

HPV+ patients with OPSCC have reduced late swallowing dysfunction after chemoradiation compared to HPV- patients. The changing epidemiology of OPSCC may play a role in toxicity reduction in these patients, independent of the increasing use of IMRT.

Radiation-induced lower cranial nerve palsy in patients with head and neck carcinoma

Radiation-induced cranial nerve palsy (RICNP) is a severe long-term complication in patients with head and neck cancer following high-dose radiation therapy (RT). We present the case report of a patient with bilateral RICNP of the hypoglossal and vagus cranial nerves (XII/X) following postoperative RT in the era prior to the introduction of intensity-modulated RT (IMRT), and an analysis of our IMRT patient cohort at risk including the case of a XII RICNP. A total of 201 patients whose glosso-pharyngeal (IX), X and XII cranial nerves had been exposed to >65 Gy definitive IMRT in our institution between January, 2002 and December, 2012 with or without systemic therapy, were retrospectively identified. A total of 151 patients out of 201 fulfilling the following criteria were included in the analysis: Locoregionally controlled disease, with a follow-up (FU) of >24 months and >65 Gy exposure of the nerves of interest. So far, one of the assessed 151 IMRT patients at risk exhibited symptoms of RICNP after 6 years. The mean/median FU of the entire cohort was 71/68 months (range, 27-145). The results were compared with literature reports. In conclusion, RICNP appears to be a rare complication. However, a longer FU and a larger sample size are required to draw reliable conclusions on the incidence of RICNP in the era of IMRT.

Functional outcomes after TORS for oropharyngeal cancer: a systematic review

Summarize functional outcomes after transoral robotic surgery (TORS) ± adjuvant therapy for oropharyngeal cancer (OPC). A systematic review was conducted. The MEDLINE database was searched (MeSH terms: TORS, pharyngeal neoplasms, oropharyngeal neoplasms). Peer-reviewed human subject papers published through December 2013 were included. Exclusion criteria were as follows: (1) case report design (n < 10), (2) review article, or (3) technical, animal, or cadaver studies. Functional outcomes extracted included feeding tube dependence, swallow examination findings, speech ratings, velopharyngeal insufficiency, pneumonia, and oral intake measures. Twelve papers comprising 441 patients with OPC treated with TORS ± adjuvant therapy were included. Feeding tube rates were the most commonly reported functional outcome. Excluding prophylactic placement, 18-39% of patients required gastrostomy placement, typically during adjuvant therapy. Chronic gastrostomy dependence ranged from 0 to 7% (mean follow-up 11-26 months), regardless of disease stage. Composite MD Anderson Dysphagia Inventory (MDADI) scores ranged from 65.2 to 78 (89 patients, 3 series, mean follow-up 12-13 months). Videofluoroscopic swallowing studies were not systematically reported. Incidence of postoperative pneumonia was 0-7%. Predictors of swallowing function included baseline function, T-stage, N-stage, tongue base primary tumors, and adjuvant chemoradiation. Rates of transient hypernasality were 4-9%. A single study suggested dose-dependent effects of adjuvant therapy (none, radiation alone, chemoradiation) on diet scores at 6 and 12 months. Crude end points of functional recovery after TORS ± adjuvant therapy suggest promising swallowing outcomes, depending on the functional measure reported.

Changes in circulating microRNAs after radiochemotherapy in head and neck cancer patients

INTRODUCTION

Circulating microRNAs (miRNAs) are easily accessible and have already proven to be useful as prognostic markers in cancer patients. However, their origin and function in the circulation is still under discussion. In the present study we analyzed changes in the miRNAs in blood plasma of head and neck squamous cell carcinoma (HNSCC) patients in response to radiochemotherapy and compared them to the changes in a cell culture model of primary HNSCC cells undergoing simulated anti-cancer therapy.

MATERIALS AND METHODS

MiRNA-profiles were analyzed by qRT-PCR arrays in paired blood plasma samples of HNSCC patients before therapy and after two days of treatment. Candidate miRNAs were validated by single qRT-PCR assays. An in vitro radiochemotherapy model using primary HNSCC cell cultures was established to test the possible tumor origin of the circulating miRNAs. Microarray analysis was performed on primary HNSCC cell cultures followed by validation of deregulated miRNAs via qRT-PCR.

RESULTS

Unsupervised clustering of the expression profiles using the six most regulated miRNAs (miR-425-5p, miR-21-5p, miR-106b-5p, miR-590-5p, miR-574-3p, miR-885-3p) significantly (p = 0.012) separated plasma samples collected prior to treatment from plasma samples collected after two days of radiochemotherapy. MiRNA profiling of primary HNSCC cell cultures treated in vitro with radiochemotherapy revealed differentially expressed miRNAs that were also observed to be therapy-responsive in blood plasma of the patients (miR-425-5p, miR-21-5p, miR-106b-5p, miR-93-5p) and are therefore likely to stem from the tumor. Of these candidate marker miRNAs we were able to validate by qRT-PCR a deregulation of eight plasma miRNAs as well as miR-425-5p and miR-93-5p in primary HNSCC cultures after radiochemotherapy.

CONCLUSION

Changes in the abundance of circulating miRNAs during radiochemotherapy reflect the therapy response of primary HNSCC cells after an in vitro treatment. Therefore, the responsive miRNAs (miR-425-5p, miR-93-5p) may represent novel biomarkers for therapy monitoring. The prognostic value of this exciting observation requires confirmation using an independent patient cohort that includes clinical follow-up data.