Mesenchymal Stem/Stromal Cell Therapy for Radiation-Induced Xerostomia in Previous Head and Neck Cancer Patients: A Phase II Randomized, Placebo-Controlled Trial

PURPOSE

No effective treatment exists for radiation-induced xerostomia. The objective of this study was to compare the effect of adipose-derived mesenchymal stem/stromal cell (ASC) injection, relative to placebo, on salivary gland function in patients with radiation-induced xerostomia.

PATIENT AND METHODS

In this single-centre, double-blind, placebo-controlled trial, patients with hyposalivation were randomised to receive ultrasound-guided injections of allogeneic ASCs or placebo into the submandibular glands. Patients were followed for 4 months. We evaluated unstimulated whole salivary flow rate (UWS), stimulated salivary flow rate, and patient-reported outcomes. Adverse events were recorded and immune response determined in blood samples.

RESULTS

We enrolled 120 patients. ASC treatment resulted in a statistically significant UWS increase of 0.04 [95% confidence interval (CI), 0.02-0.06] mL/min (38%) compared with pretreatment baseline whereas placebo treatment did not cause a significant increase [0.01 (95% CI, -0.01 to 0.04) mL/min (21%)]. Both the ASC and placebo treatment yielded notable symptom reductions, with dry mouth decreasing by 13.6 and 7.7 units, sticky saliva decreased by 14.8 and 9.3 units, swallowing difficulties decreased by 7.9 and 8.0 units, and the summary score of the Xerostomia Questionnaire decreased 5.9 and 5.1 units for the ASC and placebo arms, respectively. We found no statistically significant group difference between the ASC and placebo arms for any of the outcomes.

CONCLUSIONS

We could not confirm superiority of the ASC relative to placebo. ASC therapy significantly improved UWS in previous patients with head and neck cancer, whereas placebo resulted in an insignificant increase.

Mesenchymal Stromal/Stem Cell Therapy Improves Salivary Flow Rate in Radiation-Induced Salivary Gland Hypofunction in Preclinical in vivo Models: A Systematic Review and Meta-Analysis

BACKGROUND

Mesenchymal stromal/stem cells (MSCs) have been suggested for salivary gland (SG) restoration following radio-induced salivary gland damage. This study aimed to determine the safety and effectiveness of MSC therapy on radio-induced SG damage and hypofunction in preclinical in vivo studies.

METHODS

PubMed and EMBASE were systematically searched for preclinical in vivo interventional studies evaluating efficacy and safety of MSC treatment following radio-induced salivary gland damage published before 10th of January 2022. The primary endpoint was salivary flow rate (SFR) evaluated in a meta-analysis. The study protocol was published and registered on PROSPERO ( www.crd.ac.uk/prospero ), registration number CRD42021227336.

RESULTS

A total of 16 preclinical in vivo studies were included for qualitative analysis (858 experimental animals) and 13 in the meta-analysis (404 experimental animals). MSCs originated from bone marrow (four studies), adipose tissue (10 studies) and salivary gland tissue (two studies) and were administered intravenously (three studies), intra-glandularly (11 studies) or subcutaneously (one study). No serious adverse events were reported. The overall effect on SFR was significantly increased with a standardized mean difference (SMD) of 6.99 (95% CI: 2.55-11.42). Studies reported improvements in acinar tissue, vascular areas and paracrine factors.

CONCLUSION

In conclusion, this systematic review and meta-analysis showed a significant effect of MSC therapy for restoring SG functioning and regenerating SG tissue following radiotherapy in preclinical in vivo studies without serious adverse events. MSC therapy holds significant therapeutic potential in the treatment of radio-induced xerostomia, but comprehensive, randomized, clinical trials in humans are required to ascertain their efficacy in a clinical setting.

Outcomes of transoral robotic surgery for early-stage oropharyngeal squamous cell carcinoma with low rates of adjuvant therapy: A consecutive single-institution study from 2013 to 2020

INTRODUCTION

The incidence of oropharyngeal squamous cell carcinoma (OPSCC) has increased in recent decades, driven by infection with human papillomavirus (HPV). Transoral robotic surgery (TORS) and neck dissection (ND) has been employed as an alternative to radiotherapy/chemoradiotherapy. The current literature is lacking studies providing an exhaustive overview of recurrence characteristics and long-term outcomes in TORS-treated OPSCC-patients.

METHODS

All patients treated for OPSCC with primary TORS + ND in Eastern Denmark between 2013 and 2020 were included in the study. The aim was to explore overall survival (OS), recurrence-free survival (RFS), recurrence patterns, and ultimate failure rate (UFR). OS and RFS were examined using the Kaplan-Meier method. Cox proportional regression analyses were employed to examine effect of different variables on risk of death and recurrence.

RESULTS

The study included 153 patients of which 88.9 % (n = 136) were treated with TORS alone while 11.1 % (n = 17) received adjuvant therapy. The 1-, 3-, and 5-year OS were 97.4 %, 94.1 %, and 87.6 % while 1-, 3-, and 5-year RFS were 96.6 %, 87.8 %, and 84.9 %. The UFR was 6.5 % in the cohort. Patients with HPV+/p16 + OPSCC had a significantly better 5-year OS of 92.3 % than patients with discordant or double-negative HPV/p16 status (OS = 73.3 %). No differences in outcomes between patients treated with or without adjuvant therapy were found in regression analysis.

CONCLUSION

Excellent survival and disease control was obtained with TORS + ND in this cohort, despite lesser application of adjuvant therapy than other TORS-centers, implying that TORS without adjuvant therapy can be successfully applied in treatment of early-stage OPSCC.

Clinical and prognostic differences in oropharyngeal squamous cell carcinoma in USA and Denmark, two HPV high-prevalence areas

BACKGROUND

Uncertainty persists regarding clinical and treatment variations crucial to consider when comparing high human papillomavirus (HPV)-prevalence oropharyngeal squamous cell carcinoma (OPSCC) cohorts for accurate patient stratification and replicability of clinical trials across different geographical areas.

METHODS

OPSCC patients were included from The University of Texas MD Anderson Cancer Center (UTMDACC), USA and from The University Hospital of Copenhagen, Denmark from 2015-2020, (n = 2484). Outcomes were 3-year overall survival (OS) and recurrence-free interval (RFI). Subgroup analyses were made for low-risk OPSCC patients (T1-2N0M0) and high-risk patients (UICC8 III-IV).

RESULTS

There were significantly more HPV-positive (88.2 % vs. 63.1 %), males (89.4 % vs. 74.1 %), never-smokers (52.1 % vs. 23.7 %), lower UICC8-stage (I/II: 79.3 % vs. 68 %), and fewer patients treated with radiotherapy (RT) alone (14.8 % vs. 30.3 %) in the UTMDACC cohort. No difference in the adjusted OS was observed (hazard ratio [HR] 1.21, p = 0.23), but a significantly increased RFI HR was observed for the Copenhagen cohort (HR: 1.74, p = 0.003). Subgroup analyses of low- and high-risk patients revealed significant clinical and treatment differences. No difference in prognosis was observed for low-risk patients, but the prognosis for high-risk patients in the Copenhagen cohort was worse (OS HR 2.20, p = 0.004, RFI HR 2.80, p = 0.002).

CONCLUSIONS

We identified significant differences in clinical characteristics, treatment modalities, and prognosis between a Northern European and Northern American OPSCC population. These differences are important to consider when comparing outcomes and for patient stratification in clinical trials, as reproducibility might be challenging.

Long-Term Outcome Following Treatment With Allogeneic Mesenchymal Stem/Stromal Cells for Radiation-Induced Hyposalivation and Xerostomia

BACKGROUND

Adipose-derived mesenchymal stem/stromal cells (ASCs) are proposed as a new xerostomia treatment. The study evaluated the long-term safety and effectiveness of allogeneic ASCs in radiation-induced xerostomia among patients with previous oropharyngeal cancer.

METHODS

This study constitutes 3-year follow-up on the original 10 patients who received allogeneic ASCs injections to the submandibular and parotid glands as part of the MESRIX-II trial. The MESRIX-II trial included the preliminary 4-month follow-up. The primary endpoint was long-term safety. Secondary endpoints were effectiveness evaluated by changes in salivary flow rate and patient-reported outcomes (PROs). Immune response was evaluated by assessing the development of donor-specific antibodies (DSA).

FINDINGS

All 10 MESRIX-II patients completed the long-term follow-up (ie, no missing data). During the long-term follow-up, 2 patients encountered a significant adverse event, which was determined to be unrelated to the treatment. No DSAs were detectable at 3 years. The stimulated salivary flow rate increased significantly from an average of 0.66 mL/minute at baseline to 0.86 mL/minute at follow-up, corresponding to an increase of 0.20 [95% CI 0.08 to 0.30] mL/minute, or approximately 30%. Among the PROs, sticky saliva symptoms were reduced, with a -20.0 [95% CI -37.3 to -2.7] units.

INTERPRETATION

In conclusion, this study is the first to present long-term follow-up outcomes of allogeneic ASC treatment as a therapeutic option for radiation-induced xerostomia. The study found that ASC treatment appears safe, and there were no indications of adverse immune responses at the 3-year follow-up. Further studies are warranted to evaluate the findings in larger settings.

Effectiveness and safety of mesenchymal stem/stromal cell for radiation-induced hyposalivation and xerostomia in previous head and neck cancer patients (MESRIX-III): a study protocol for a single-centre, double-blinded, randomised, placebo-controlled, phase II study

BACKGROUND

A predominant side effect of radiotherapy for head and neck cancer is salivary gland hypofunction and xerostomia leading to debilitating oral disorders and impaired quality of life (QoL). Intraglandular mesenchymal stem cell therapy has shown promising results as a treatment for xerostomia.

METHODS

This is a randomised, double-blinded, placebo-controlled, parallel-group, prospective, single-centre trial investigating the safety, tolerability, and effectiveness of allogeneic stem cells as a treatment for radiation-induced hyposalivation and xerostomia for previous head and neck cancer patients. We will include a total of 120 patients who previously have been treated with radiotherapy for a head and neck cancer in Denmark. Participants will be randomly assigned using block randomisation to one of two parallel groups in a 1:1 ratio to receive ultrasound-guided injection of allogeneic adipose-derived mesenchymal stem cell (ASC) (n = 60) or placebo (n = 60) into the submandibular glands. Placebo will consist of CryoStor10 (BiolifeSolutions), the freeze media for ASCs containing 10% dimethyl sulfoxide (DMSO). The primary endpoint is change in unstimulated whole saliva flow rate. The secondary endpoints are change in stimulated whole saliva flow rate, QoL, and composition of saliva. Further secondary endpoints are safety and immune response (human leukocyte antigen (HLA) response) to the stem cells will be assessed. Patients are evaluated at baseline (before treatment), after 4 months, and after 12 months. All study personnel, except study personnel thawing and preparing the treatment for injection, and participants will be blinded to group assignment. Unblinded study personnel will not participate in the outcome assessment.

DISCUSSION

The trials will investigate the efficacy and safety of ASC injection to the submandibular gland as a potential new treatment for post-radiation xerostomia. We hope the results will pave the way for a clinically relevant treatment to ameliorate patients with xerostomia, a severely hampering condition.

TRIAL REGISTRATION

The study is approved by the Danish Data Protection Agency (protocol number P-2020-1164), the National Ethics Committee protocol number: (Protocol number: 1802872), and the Danish Medical Agency (2018-000348-24). The protocol was registered at the ClinicalTrials.gov database (NCT04776538).

Pretreatment Neutrophil-to-Lymphocyte Ratio as a Prognostic Marker for the Outcome of HPV-Positive and HPV-Negative Oropharyngeal Squamous Cell Carcinoma

The incidence of oropharyngeal squamous cell carcinoma (OPSCC) has increased in the past decades due to carcinogenic HPV infection. As this patient group suffers from considerable mortality and treatment morbidity it is important to improve prognostic strategies in OPSCC. Inflammation plays a key role in cancer and the neutrophil-to-lymphocyte ratio (NLR) in blood has been suggested as a prognostic factor for OPSCC. This study aimed to investigate the prognostic impact of NLR on overall survival (OS) and recurrence-free survival (RFS) in a retrospective cohort of 1370 patients. Included patients had pretreatment neutrophil and lymphocyte counts available, as well as a known HPV status. Patients were treated with curative intent according to Danish national guidelines. We stratified patients in groups by NLR < 2, NLR 2−4, or NLR > 4 and analyzed the influence of the NLR tertile on OS and RFS. Kaplan−Meier curves illustrated survival probability in OS and RFS in the general cohort and were stratified by HPV status. We found that an increasing NLR was associated with inferior OS (HR = 1.5 for NLR > 4) and RFS (HR = 1.6 for NLR 2−4; HR = 1.8 for NLR > 4) in multivariable analysis. The Kaplan−Meier curves displayed inferior OS and RFS with an increasing NLR for both HPV+ and HPV− patients. In conclusion, we showed that an increasing NLR is prognostic for a worse outcome of OPSCC independently of HPV status. There are possible uses of NLR in prognostication and treatment de-escalation although further studies are warranted to determine the clinical utility.

The Incidence, Survival, and HPV Impact of Second Primary Cancer following Primary Oropharyngeal Squamous Cell Carcinoma: A 20-Year Retrospective and Population-Based Study

Second primary cancer (SPC) is the second most common cause of death among patients diagnosed with head and neck cancer. This study examined the risk of SPC following oropharyngeal squamous cell carcinoma (OPSCC) and the impact of human papillomavirus (HPV) on survival following SPC. The study was a population-based, retrospective study including all patients diagnosed with OPSCC in eastern Denmark from 2000-2020 who received curative intended treatment. The incidence rate ratio (IRR), age-adjusted incidence rates (AAIR), and hazard ratios (HR) were calculated. A total of 2584 patients with primary OPSCC were included (median follow-up time: 3.1 years), with 317 patients (12.3%) diagnosed with SPC. The risk of SPC was approximately five times the occurrence of cancer in the general population (IRR: 4.96). The median time to SPC after a primary OPSCC was 2.0 years (interquartile range (IQR) = 0.6-4.2 years). HPV-positive (HPV+) patients had a significantly longer median time to SPC, and a significant better survival compared to HPV-negative (HPV-) patients. SPC was most frequently found in lungs, head, and neck (LHN) for HPV- OPSCC patients and lungs followed by gender-specific (prostate, ovaries, or endometrium) for HPV+ OPSCC. There was a significant difference between the two groups when distributed between "within" or "outside" LHN. Patients with SPC outside LHN had a significant better overall survival. This knowledge should be considered during post-treatment surveillance and might guide targeted imaging.

Diagnostic Accuracy of HPV Detection in Patients with Oropharyngeal Squamous Cell Carcinomas: A Systematic Review and Meta-Analysis

The aim of the study was to evaluate the diagnostic accuracy of Human Papillomavirus (HPV) techniques in oropharyngeal cancer. PubMed, EMBASE, the Cochrane Library and clinicaltrials.org were systematically searched for studies reporting methods of HPV detection. Primary outcomes were sensitivity and specificity of HPV detection. In this case, 27 studies were included (n = 5488, 41.6% HPV+). In this case, 13 studies evaluated HPV detection in tumour tissue, nine studies examined HPV detection in blood samples and five studies evaluated HPV detection in oral samples. Accuracy of HPV detection in tumour tissue was high for all detection methods, with pooled sensitivity ranging from 81.1% (95% CI 71.9-87.8) to 93.1% (95% CI 87.4-96.4) and specificity ranging from 81.1% (95% CI 71.9-87.8) to 94.9% (95% CI 79.1-98.9) depending on detection methods. Overall accuracy of HPV detection in blood samples revealed a sensitivity of 81.4% (95% CI 62.9-91.9) and a specificity of 94.8% (95% CI 91.4-96.9). In oral samples pooled sensitivity and specificity were lower (77.0% (95% CI 68.8-83.6) and 74.0% (95% CI 58.0-85.4)). In conclusion, we found an overall high accuracy for HPV detection in tumour tissue regardless of the HPV detection method used. HPV detection in blood samples may provide a promising new way of HPV detection.

Continuing rise in oropharyngeal cancer in a high HPV prevalence area: A Danish population-based study from 2011 to 2014

BACKGROUND

Human papillomavirus (HPV) is a critical element in the rising incidence of oropharyngeal squamous cell carcinoma (OPSCC), although whether this trend will continue, and the types of HPV responsible, are currently unknown. We previously demonstrated an increased incidence of HPV-related OPSCC in the high HPV prevalence area of Eastern Denmark from 2000 to 2010. Therefore, we investigated if the incidence for OPSCC continued to rise, the association to HPV and putative HPV-types in Eastern Denmark from 2011 to 14. We then projected the expected incidence of OPSCC versus cervical cancer through to 2020.

PATIENTS AND METHODS

Patients with OPSCC (tonsillar squamous cell carcinoma [TSCC] and base of tongue squamous cell carcinoma [BSCC]) were identified via the Danish Head and Neck Cancer Group and the Danish Pathology Databank (n = 700). Tumours were re-reviewed and assessed using p16 immunohistochemistry, HPV DNA polymerase chain reaction (PCR), with genotyping by next generation sequencing.

RESULTS

Sixty-two percent (432/700) of tumours were HPV-positive (HPV+). The total incidence rate (per 100.000) for OPSCC increased from 4.0 in 2011 to 4.5 in 2014, primarily due to a rise in HPV+ TSCCs and HPV+ BSCCs, although numbers of HPV-negative (HPV-) OPSCC also increased during the study period. The majority of HPV+ tumours were HPV16 DNA positive (86%), but we also identified HPV33 DNA (6%), HPV35 DNA (4%) and others (3%), including HPV18, 26, 31, 45, 56, 58, 59 and HPV67.

CONCLUSION

An increasing incidence of OPSCC is driven primarily by HPV+ OPSCC. Sixty-two percent of tumours were HPV+, which is a high-prevalence, although the lower number of HPV- cases has yet to stabilise. HPV16 was the predominant genotype, although a significant proportion (14%) was of another genotype. Our projections suggest that the number of HPV+ OPSCC will exceed that of cervical cancer in 2016 in Eastern Denmark.

Novel nomograms for survival and progression in HPV+ and HPV- oropharyngeal cancer: a population-based study of 1,542 consecutive patients

BACKGROUND

No study has combined tumour and clinical covariates for survival to construct an individual risk-profile for overall survival (OS), time to progression (TTP), and survival after progression (SAP) in patients with HPV+ and HPV- oropharyngeal squamous cell carcinoma (OPSCC). Based on the largest-to-date, unselected, population-based cohort of patients diagnosed with OPSCC, we performed a comprehensive analysis of long-term OS, TTP, and SAP and constructed novel nomograms to evaluate patients' prognoses.

RESULTS

At a median follow-up of 4.0 years (range: 0.8-15.8 yrs.), 690 deaths were recorded. The 5-year OS, TTP, and SAP for the HPV+/p16+ subgroup were 77%, 82%, and 33, vs. 30%, 66%, and 6% for the HPV-/p16- group (P < 0.01). 376 patients failed to maintain disease control with a median TTP of 13 months in the HPV+/p16+ subgroup vs. 8.5 months in the HPV-/p16- subgroup (P < 0.05). HPV combined with p16 status remained one of the most informative covariates in the final Cox regression model for OS, TTP, and SAP.

METHODS

We included all patients diagnosed with OPSCC (n = 1,542) between 2000-2014 in Eastern Denmark. Survival rates were estimated by the Kaplan-Meier method. A multivariate Cox regression model was used to construct predictive, internally validated nomograms.

CONCLUSION

The HPV+/p16+ subgroup had improved OS, TTP, and SAP compared with other combinations of HPV and p16 after adjusting for covariates. Nomograms were constructed for 1-, 5- and 10-year survival probability. Models may aid patients and clinicians in their clinical decision making as well as in counselling, research, and trial design.