Aldehyde dehydrogenase 3A1 activation prevents radiation-induced xerostomia by protecting salivary stem cells from toxic aldehydes.

Xerostomia (dry mouth) is the most common side effect of radiation therapy in patients with head and neck cancer and causes difficulty speaking and swallowing. Since aldehyde dehydrogenase 3A1 (ALDH3A1) is highly expressed in mouse salivary stem/progenitor cells (SSPCs), we sought to determine the role of ALDH3A1 in SSPCs using genetic loss-of-function and pharmacologic gain-of-function studies. Using DarkZone dye to measure intracellular aldehydes, we observed higher aldehyde accumulation in irradiated Aldh3a1-/- adult murine salisphere cells and in situ in whole murine embryonic salivary glands enriched in SSPCs compared with wild-type glands. To identify a safe ALDH3A1 activator for potential clinical testing, we screened a traditional Chinese medicine library and isolated d-limonene, commonly used as a food-flavoring agent, as a single constituent activator. ALDH3A1 activation by d-limonene significantly reduced aldehyde accumulation in SSPCs and whole embryonic glands, increased sphere-forming ability, decreased apoptosis, and improved submandibular gland structure and function in vivo after radiation. A phase 0 study in patients with salivary gland tumors showed effective delivery of d-limonene into human salivary glands following daily oral dosing. Given its safety and bioavailability, d-limonene may be a good clinical candidate for mitigating xerostomia in patients with head and neck cancer receiving radiation therapy.

Feasibility of optimizing intensity-modulated radiation therapy plans based on measured mucosal dose adjacent to dental fillings and toxicity outcomes.

We prospectively investigated the feasibility of IMRT treatment plan optimization based on dosimeter measurements of lateral tongue mucosal dose adjacent to the dental fillings and evaluated dose-toxicity relationship and factors affecting oral mucositis (OM) in head and neck cancer patients. Twenty-nine head and neck cancer patients with metallic dental fillings who were scheduled to undergo fractionated external beam radiation therapy (RT) ± chemotherapy were enrolled. The lateral tongue dose was measured and if the calculated dose for the entire treatment was ≥35 Gy, a re-plan was generated to reduce the lateral tongue mucosal dose. OM was graded weekly according to Common Terminology Criteria for Adverse Events version 4.0 and the patients completed the Oral Mucositis Weekly Questionnaire-Head and Neck Cancer. The result showed that it was not feasible to optimize the IMRT plan based on measured tongue dose in most of the patients who needed re-plan as re-planning compromised the target coverage in 60% of these patients. The duration of grade (Gr) 2 OM was correlated with measured lateral tongue dose (P = 0.050). Concurrent cetuximab was significantly associated with faster onset of Gr2 OM than concurrent cisplatin (P = 0.006) and with longer duration of OM (P = 0.041) compared to concurrent cisplatin or IMRT-alone. The pattern of reported pain over time was significantly different for each treatment type (RT and cetuximab, RT and cisplatin and RT-alone) and depending on the dose level (P = 0.006). In conclusion, optimizing the IMRT plan based on measured lateral tongue dose was not feasible. Measured lateral tongue dose was significantly correlated with longer duration of OM ≥Gr2, and concurrent cetuximab was associated with earlier onset and longer duration of OM ≥Gr2.

Long-term Outcomes of Bevacizumab and Chemoradiation for Locoregionally Advanced Nasopharyngeal Carcinoma: A Nonrandomized Controlled Trial.

Importance: The long-term outcomes associated with adding bevacizumab, a vascular endothelial growth factor inhibitor, to standard chemoradiation have continued to be favorable for a group of patients with locoregionally advanced nasopharyngeal carcinoma (NPC). Objective: To assess long-term toxic effects and clinical outcomes associated with chemotherapy, radiation therapy (RT), and bevacizumab for NPC. Design, Setting, and Participants: This single-arm phase II nonrandomized controlled trial was conducted by the National Cancer Trials Network group and NRG Oncology (formerly Radiation Therapy Oncology Group), with accrual from December 13, 2006, to February 5, 2009, and data analysis from June 26 to July 1, 2019. The study was conducted at 19 cancer centers with a median (IQR) follow-up of 9.0 (7.7-9.3) years. Included patients were adults (aged ≥18 years) with NPC that was World Health Organization (WHO) histologic grade I to IIb or III, American Joint Committee on Cancer stage IIB or greater, and with or without lymph node involvement. Interventions: Patients received 3 cycles of bevacizumab (15 mg/kg) concurrently with standard cisplatin (100 mg/m2) and RT (69.96 Gy) followed by 3 cycles of adjuvant bevacizumab (15 mg/kg) given concurrently with cisplatin (80 mg/m2) and fluorouracil (1000 mg/m2/d). Main Outcomes and Measures: The primary end point was grade 4 hemorrhage or grade 5 adverse events in the first year. Secondary end points were locoregional progression-free (LRPF) interval, distant metastasis-free (DMF) interval, progression-free survival (PFS), overall survival (OS), and other adverse events. Long-term toxic effects and clinical outcomes were reported due to the limited follow-up in the initial report for this trial and the importance of long-term outcomes when combining bevacizumab with chemoradiation. Results: Among 46 patients with NPC who were enrolled, 44 patients were analyzed (29 males [65.9%]; 23 Asian [52.3%], 2 Black [4.5%], and 16 White [36.4%]; 38 not Hispanic [86.4%]; median [IQR] age, 48.5 [39.0-56.0] years). There were 33 patients with a Zubrod performance status of 0, indicating that they were fully functional and asymptomatic (75.0%); 32 patients with a WHO histologic grade of IIb or III (72.7%); and 39 patients with stage III or IVB disease (88.6%). Among analyzed patients, 42 individuals received radiation therapy of 69.96 Gy or greater (95.5%; dose range, 65.72-70.00 Gy); 30 patients received 3 cycles of cisplatin (68.2%) with RT, and 31 patients received 3 cycles of bevacizumab with RT (70.5%); this was followed by 3 cycles of adjuvant cisplatin in 21 patients (47.7%), fluorouracil in 24 patients (54.5%), and bevacizumab in 23 patients (52.3%). No grade 4 hemorrhage or grade 5 AEs were reported in the first year or thereafter. Late grade 3 AEs occurred in 16 patients (36.4%), including 7 patients with dysphagia (15.9%), 6 patients with hearing impairment (13.6%), and 2 patients with dry mouth (4.5%). The 1- and 5-year rates of feeding tube use were 5 of 41 patients (12.2%) and 0 of 27 patients, respectively. There were 19 patients (43.2%) who progressed or died without disease progression (6 patients with locoregional progression [13.6%], 8 patients with distant progression [18.2%], and 5 patients who died without progression [11.4%]). The 5- and 7-year rates were 79.5% (95% CI, 67.6%-91.5%) and 69.7% (95% CI, 55.9%-83.5%) for OS, 61.2% (95% CI, 46.8%-75.6%) and 56.3% (95% CI, 41.5%-71.1%) for PFS, 74.9% (95% CI, 61.4%-86.6%) and 72.3% (95% CI, 58.4%-84.7%) for LRPF interval, and 79.5% (95% CI,66.4%-90.0%) for both times for DMF interval. Among 13 patients who died, death was due to disease in 8 patients (61.5%). Conclusions and Relevance: In this nonrandomized controlled trial, no grade 4 hemorrhage or grade 5 AEs were reported in the first year or thereafter among patients with NPC receiving bevacizumab combined with chemoradiation. The rate of distant metastasis was low although 89% of patients had stage III to IVB disease, suggesting that further investigation may be warranted. Trial Registration: ClinicalTrials.gov Identifier: NCT00408694.

Botulinum Toxin Confers Radioprotection in Murine Salivary Glands.

PURPOSE: Xerostomia is a common radiation sequela, which has a negative impact on the quality of life of patients with head and neck cancer. Current treatment strategies offer only partial relief. Botulinum toxins (BTX) have been successfully used in treating a variety of radiation sequelae such as cystitis, proctitis, fibrosis, and facial pain. The purpose of this study was to evaluate the effect of BTX on radiation-induced salivary gland damage. METHODS AND MATERIALS: We used a previously established model for murine salivary gland irradiation (IR). The submandibular glands (SMGs) of C5BL/6 mice (n=6/group) were injected with saline or BTX 72 hours before receiving 15 Gy of focal irradiation. Saliva flow was measured 3, 7, and 28 days after treatment. The SMGs were collected for immunohistochemistry, confocal microscopy, and Western blotting. A cytokine array consisting of 40 different mouse cytokines was used to evaluate cytokine profiles after radiation treatment. RESULTS: Irradiated mice showed a 50% reduction in saliva flow after 3 days, whereas mice preinjected with BTX had 25% reduction in saliva flow (P<.05). Cell death detected by TUNEL staining was similar in SMG sections of both groups. However, neutrophil infiltrate, detected by myeloperoxidase staining, was 3-fold lower for the BTX treated mice. A cytokine array showed a 2-fold upregulation of LPS-induced chemokine (LIX/CXCL5) 3 days after IR. BTX pretreatment reduced LIX levels by 40%. At 4 weeks after IR, the saline (control) group showed a 40% reduction in basal SMG weight, compared with 20% in the BTX group. Histologically, BTX-pretreated glands showed relative preservation of acinar structures after radiation. CONCLUSIONS: These data suggest that BTX pretreatment ameliorates radiation-induced saliva dysfunction. Moreover, we demonstrate a novel role for CXCL5 in the acute phase of salivary gland damage after radiation. These results carry important clinical implications for the treatment of xerostomia in patients with head and neck cancer.

Neurotrophic factor GDNF promotes survival of salivary stem cells.

Stem cell-based regenerative therapy is a promising treatment for head and neck cancer patients that suffer from chronic dry mouth (xerostomia) due to salivary gland injury from radiation therapy. Current xerostomia therapies only provide temporary symptom relief, while permanent restoration of salivary function is not currently feasible. Here, we identified and characterized a stem cell population from adult murine submandibular glands. Of the different cells isolated from the submandibular gland, this specific population, Lin-CD24+c-Kit+Sca1+, possessed the highest capacity for proliferation, self renewal, and differentiation during serial passage in vitro. Serial transplantations of this stem cell population into the submandibular gland of irradiated mice successfully restored saliva secretion and increased the number of functional acini. Gene-expression analysis revealed that glial cell line-derived neurotrophic factor (Gdnf) is highly expressed in Lin-CD24+c-Kit+Sca1+ stem cells. Furthermore, GDNF expression was upregulated upon radiation therapy in submandibular glands of both mice and humans. Administration of GDNF improved saliva production and enriched the number of functional acini in submandibular glands of irradiated animals and enhanced salisphere formation in cultured salivary stem cells, but did not accelerate growth of head and neck cancer cells. These data indicate that modulation of the GDNF pathway may have potential therapeutic benefit for management of radiation-induced xerostomia.

Cost-effectiveness landscape analysis of treatments addressing xerostomia in patients receiving head and neck radiation therapy.

Head and neck (H&N) radiation therapy (RT) can induce irreversible damage to the salivary glands thereby causing long-term xerostomia or dry mouth in 68%-85% of the patients. Not only does xerostomia significantly impair patients' quality-of-life (QOL) but it also has important medical sequelae, incurring high medical and dental costs. In this article, we review various measures to assess xerostomia and evaluate current and emerging solutions to address this condition in H&N cancer patients. These solutions typically seek to accomplish 1 of the 4 objectives: (1) to protect the salivary glands during RT, (2) to stimulate the remaining gland function, (3) to treat the symptoms of xerostomia, or (4) to regenerate the salivary glands. For each treatment, we assess its mechanisms of action, efficacy, safety, clinical utilization, and cost. We conclude that intensity-modulated radiation therapy is both the most widely used prevention approach and the most cost-effective existing solution and we highlight novel and promising techniques on the cost-effectiveness landscape.

Palifermin reduces severe mucositis in definitive chemoradiotherapy of locally advanced head and neck cancer: a randomized, placebo-controlled study.

PURPOSE: Oral mucositis (OM) is a debilitating toxicity of chemoradiotherapy for head and neck cancer (HNC). This randomized, placebo-controlled, double-blind study evaluated the efficacy and safety of palifermin to reduce OM associated with definitive chemoradiotherapy for locally advanced HNC. PATIENTS AND METHODS: Patients receiving conventionally fractionated radiotherapy (2.0 Gy/d, 5 days/wk to 70 Gy) with cisplatin (100 mg/m(2) on days 1, 22, and 43) received palifermin (180 µg/kg) or placebo before starting chemoradiotherapy and then once weekly for 7 weeks. The primary end point was the incidence of severe, observable, and functional OM (WHO grade 3 to 4). RESULTS: The palifermin (n = 94) and placebo (n = 94) arms were well balanced. The incidence of severe OM was significantly lower for palifermin than for placebo (54% v 69%; P = .041). In the palifermin arm, median time to severe OM was delayed (47 v 35 days), median duration of severe OM was shortened (5 v 26 days), and the incidence of xerostomia grade ≥ 2 was lower (67% v 80%), favoring palifermin; however, the differences were not significant after multiplicity adjustment. Opioid analgesic use, average mouth and throat soreness scores, and chemoradiotherapy compliance were not significantly different between treatment arms. Adverse events were similar between arms (98%, palifermin; 93%, placebo). The most common study drug-related adverse events were rash, flushing, and dysgeusia. After median follow-up of 25.8 months, overall survival and progression-free survival were similar between treatment arms. CONCLUSION: Although palifermin reduced severe functional OM, its role in the management of locally advanced HNC during chemoradiotherapy remains to be elucidated.

Mucositis-related morbidity and resource utilization in head and neck cancer patients receiving radiation therapy with or without chemotherapy.

The objective of this study was to estimate health care-resource utilization in head and neck cancer (HNC) patients. This was a prospective, longitudinal, multicenter, noninterventional study of mucositis in patients receiving radiation with or without chemotherapy for HNC. Mouth and throat soreness and functional impairment were measured using the Oral Mucositis Weekly Questionnaire-HNC. Resource utilization data were obtained from patient interviews and recorded from the patient's medical chart. Seventy-five patients were enrolled from six centers. Fifty (67%) patients received concurrent chemoradiation therapy; 34 (45%) received intensity-modulated radiation therapy. Over the course of treatment, 57 (76%) patients reported severe mouth and throat soreness. Pain and functional impairment because of mouth and throat soreness increased during the course of therapy despite the use of opioid analgesics in 64 (85%) of the patients. Complications of radiation therapy resulted in increased patient visits to physicians, nurses, and nutritionists. Thirty-eight (51%) patients had a feeding tube placed. Twenty-eight patients (37%) were hospitalized, five of whom were hospitalized twice; of the 33 admissions, 10 (30%) were designated as secondary to mucositis by their treating physician. Mean length of hospitalization was 4.9 days (range: 1-16). This study demonstrates that mucositis-related pain and functional impairment is associated with increased use of costly health resources. Effective treatments to reduce the pain and functional impairment of oral mucositis are needed in this patient population.

Longitudinal evaluation of the oral mucositis weekly questionnaire-head and neck cancer, a patient-reported outcomes questionnaire.

BACKGROUND: Quality-of-life instruments that measure specific functional consequences of mucositis are needed to assess the efficacy of therapeutic interventions targeted against mucositis and to guide patient care. The authors undertook a prospective, multicenter, observational study to assess the validity, reliability, and feasibility of a new instrument, the Oral Mucositis Weekly Questionnaire-Head and Neck Cancer (OMWQ-HN). The OMWQ-HN is a patient-reported outcome questionnaire that measures the symptoms of mucositis, including mouth and throat soreness (MTS), and their impact on patient well-being and function. METHODS: The OMWQ-HN, along with the Functional Assessment of Cancer Therapy-Head and Neck (FACT-HN), was administered 5 times over an approximately 6-week period to patients with head and neck cancer (HNC) who were receiving radiation therapy with or without chemotherapy. Information on supportive care measures also was collected. RESULTS: Seventy-five patients were enrolled and completed 93% of scheduled assessments (100% at baseline). The OMWQ-HN demonstrated good test-retest reliability (correlation coefficient, 0.80-0.89). Cross-sectional analyses to assess validity showed that OMWQ-HN scores were different across levels of pain, with those in the worst pain category reporting the highest OMWQ-HN scores. Strong correlations were observed between OMWQ-HN and FACT-HN. Patients experienced increases in MTS, which corresponded with a steady decline in function. MTS scores were highest in the patients who were taking opioid analgesics, suggesting that mucositis pain continued despite standard pain therapy. CONCLUSIONS: The current results indicated that the OMWQ-HN is a valid, reliable, and feasible instrument for assessing the impact of mucositis on patients who are receiving radiation therapy with or without chemotherapy for HNC.