Orofacial pain in cancer: part II--clinical perspectives and management

Machine learning predicting acute pain and opioid dose in radiation treated oropharyngeal cancer patients

Introduction

Acute pain is common among oral cavity/oropharyngeal cancer (OCC/OPC) patients undergoing radiation therapy (RT). This study aimed to predict acute pain severity and opioid doses during RT using machine learning (ML), facilitating risk-stratification models for clinical trials.

Methods

A retrospective study examined 900 OCC/OPC patients treated with RT during 2017-2023. Pain intensity was assessed using NRS (0-none, 10-worst) and total opioid doses were calculated using morphine equivalent daily dose (MEDD) conversion factors. Analgesics efficacy was assessed using combined pain intensity and total MEDD. ML predictive models were developed and validated, including Logistic Regression (LR), Support Vector Machine (SVM), Random Forest (RF), and Gradient Boosting Machine (GBM). Model performance was evaluated using discrimination and calibration metrics, while feature importance was investigated using bootstrapping.

Results

For predicting pain intensity, the GBM demonstrated superior discrimination performance (AUROC 0.71, recall 0.39, and F1 score 0.48). For predicting the total MEDD, LR model outperformed other models (AUROC 0.67). For predicting analgesics efficacy, the SVM achieved the highest specificity (0.97), while the RF and GBM models achieved the highest AUROC (0.68). RF model emerged as the best calibrated model with an ECE of 0.02 and 0.05 for pain intensity and MEDD prediction, respectively. Baseline pain scores and vital signs demonstrated the most contributing features.

Conclusion

ML models showed promise in predicting end-of-treatment pain intensity, opioid requirements and analgesics efficacy in OCC/OPC patients. Baseline pain score and vital signs are crucial predictors. Their implementation in clinical practice could facilitate early risk stratification and personalized pain management.

Cancer neuroscience in head and neck: interactions, modulation, and therapeutic strategies

Head and neck cancer (HNC) is an aggressive malignancy with significant effects on the innervation. Not only is it at the top of the cancer spectrum with a dismal prognosis, but it also imposes considerable stress on patients and society owing to frequent neurological symptoms. With progress in cancer neuroscience, the interactions between HNC and the nervous system, as well as the underlying mechanisms, have become increasingly clear. Compelling evidence suggests communication of information between cancer and nerve cells and devastation of the neurological system with tumor growth. However, the thorough grasp of HNC in cancer neuroscience has been severely constrained by the intricacy of HNC and fragmented research. This review comprehensively organizes and summarizes the latest research on the crosstalk between HNC and the nervous system. It aims to clarify various aspects of the neurological system in HNC, including the physiology, progression, and treatment of cancer. Furthermore, the opportunities and challenges of cancer neuroscience in HNC are discussed, which offers fresh perspectives on the neurological aspects of HNC diagnosis and management.

Comparison of Machine Leaning Models for Prediction of Acute Pain Severity and On-Treatment Opioid Utilization in Oral Cavity and Oropharyngeal Cancer Patients Receiving Radiation Therapy: Exploratory Analysis from a Large-Scale Retrospective Cohort

Background

Acute pain is a common and debilitating symptom experienced by oral cavity and oropharyngeal cancer (OC/OPC) patients undergoing radiation therapy (RT). Uncontrolled pain can result in opioid overuse and increased risks of long-term opioid dependence. The specific aim of this exploratory analysis was the prediction of severe acute pain and opioid use in the acute on-treatment setting, to develop risk-stratification models for pragmatic clinical trials.

Materials and Methods

A retrospective study was conducted on 900 OC/OPC patients treated with RT during 2017 to 2023. Clinical data including demographics, tumor data, pain scores and medication data were extracted from patient records. On-treatment pain intensity scores were assessed using a numeric rating scale (0-none, 10-worst) and total opioid doses were calculated using morphine equivalent daily dose (MEDD) conversion factors. Analgesics efficacy was assessed based on the combined pain intensity and the total required MEDD. ML models, including Logistic Regression (LR), Support Vector Machine (SVM), Random Forest (RF), and Gradient Boosting Model (GBM) were developed and validated using ten-fold cross-validation. Performance of models were evaluated using discrimination and calibration metrics. Feature importance was investigated using bootstrap and permutation techniques.

Results

For predicting acute pain intensity, the GBM demonstrated superior area under the receiver operating curve (AUC) (0.71), recall (0.39), and F1 score (0.48). For predicting the total MEDD, LR outperformed other models in the AUC (0.67). For predicting the analgesics efficacy, SVM achieved the highest specificity (0.97), and best calibration (ECE of 0.06), while RF and GBM achieved the same highest AUC, 0.68. RF model emerged as the best calibrated model with ECE of 0.02 for pain intensity prediction and 0.05 for MEDD prediction. Baseline pain scores and vital signs demonstrated the most contributed features for the different predictive models.

Conclusion

These ML models are promising in predicting end-of-treatment acute pain and opioid requirements and analgesics efficacy in OC/OPC patients undergoing RT. Baseline pain score, vital sign changes were identified as crucial predictors. Implementation of these models in clinical practice could facilitate early risk stratification and personalized pain management. Prospective multicentric studies and external validation are essential for further refinement and generalizability.

Repurposing EGFR Inhibitors for Oral Cancer Pain and Opioid Tolerance

Oral cancer pain remains a significant public health concern. Despite the development of improved treatments, pain continues to be a debilitating clinical feature of the disease, leading to reduced oral mobility and diminished quality of life. Opioids are the gold standard treatment for moderate-to-severe oral cancer pain; however, chronic opioid administration leads to hyperalgesia, tolerance, and dependence. The aim of this review is to present accumulating evidence that epidermal growth factor receptor (EGFR) signaling, often dysregulated in cancer, is also an emerging signaling pathway critically involved in pain and opioid tolerance. We presented preclinical and clinical data to demonstrate how repurposing EGFR inhibitors typically used for cancer treatment could be an effective pharmacological strategy to treat oral cancer pain and to prevent or delay the development of opioid tolerance. We also propose that EGFR interaction with the µ-opioid receptor and glutamate N-methyl-D-aspartate receptor could be two novel downstream mechanisms contributing to pain and morphine tolerance. Most data presented here support that repurposing EGFR inhibitors as non-opioid analgesics in oral cancer pain is promising and warrants further research.

Systematic Review of Genetic Polymorphisms Associated with Acute Pain Induced by Radiotherapy for Head and Neck Cancers

Background/objective

Pain is the most common acute symptom following radiation therapy (RT) for head and neck cancer (HNC). The multifactorial origin of RT-induced pain makes it highly challenging to manage. Multiple studies were conducted to identify genetic variants associated with cancer pain, however few of them focused on RT-induced acute pain. In this review, we summarize the potential mechanisms of acute pain after RT in HNC and identify genetic variants associated with RT-induced acute pain and relevant acute toxicities.

Methods

A comprehensive search of Ovid Medline, EMBASE and Web of Science databases using terms including "Variants", "Polymorphisms", "Radiotherapy", "Acute pain", "Acute toxicity" published up to February 28, 2022, was performed by two reviewers. Review articles and citations were reviewed manually. The identified SNPs associated with RT-induced acute pain and toxicities were reported, and the molecular functions of the associated genes were described based on genetic annotation using The Human Gene Database; GeneCards.

Results

A total of 386 articles were identified electronically and 8 more articles were included after manual search. 21 articles were finally included. 32 variants in 27 genes, of which 25% in inflammatory/immune response, 20% had function in DNA damage response and repair, 20% in cell death or cell cycle, were associated with RT-inflammatory pain and acute oral mucositis or dermatitis. 4 variants in 4 genes were associated with neuropathy and neuropathic pain. 5 variants in 4 genes were associated with RT-induced mixed types of post-RT-throat/neck pain.

Conclusion

Different types of pain develop after RT in HNC, including inflammatory pain; neuropathic pain; nociceptive pain; and mixed oral pain. Genetic variants involved in DNA damage response and repair, cell death, inflammation and neuropathic pathways may affect pain presentation post-RT. These variants could be used for personalized pain management in HNC patients receiving RT.

Head and Neck Cancer-Related Pain: A Descriptive Analysis of the Pain Phenotypes

Objective

This study aimed to describe the clinical characteristics and prevalence of different painful phenotypes in head and neck cancer (HNC)-related pain.

Materials and Methods

A cross-sectional study was conducted on 100 patients who presented with HNC-related pain. All patients underwent a comprehensive clinical assessment and were stratified in one or more painful phenotypes constructed based on the International Classification for Orofacial Pain, first edition, and International Classification for Headache Disorders, third edition.

Results

Among the participants included, 68% were male, and the mean age of the cohort was 49.71 ± 14.14 years. The most prevalent cancer sites were the tongue (29%) and buccal mucosa (24%). The average pain intensity was 5.88 ± 2.53 on an 11-point numeric verbal pain rating scale, where 0 was indicative of "no pain" and 10 was suggestive of "worst pain imaginable". However, the worst pain intensity over the last month was 8.95 ± 1.53. The average number of pain sites per patient was 6, and the most common pain descriptors were dull ache, burning, and sharpness. Myofascial pain, jaw bone pain, and burning pain disorder were the most common phenotypes, and on average, three different phenotypes co-existed.

Conclusion

HNC-related pain has a varying and complex clinical profile, which may mirror the pain profiles of primary pain disorders, such as myofascial pain, jaw bone pain, or burning pain disorders, and often presents together as a cluster of phenotypes.

Head and Neck Cancer-Related Pain

Pain is a common and most debilitating symptom of head and neck cancers (HNC). The prevalence of pain in HNC is nearly 70%. There are no universally accepted classification or diagnostic criteria for HNC-related pain, and currently, HNC-related pain is classified based on the underlying pathophysiological mechanism, the location of the tumor, and the protagonist of pain. The clinical presentation of HNC-related pain varies and can be similar to primary pain disorders. The management of HNC-related pain primarily consists of pharmacotherapy. However, in some cases, interventions may be needed. This article will present a case study and review the epidemiology, diagnostic criteria and classification, clinical features, pathophysiology, and HNC-related pain management.

MASCC/ISOO expert opinion on the management of oral problems in patients with advanced cancer

PURPOSE

The Palliative Care Study Group in conjunction with the Oral Care Study Group of the Multinational Association for Supportive Care in Cancer (MASCC) formed a sub-group to develop evidence-based guidance on the management of common oral problems in patients with advanced cancer.

METHODS

This guidance was developed in accordance with the MASCC Guidelines Policy. A search strategy for Medline was developed, and the Cochrane Database of Systematic Reviews and the Cochrane Central Register of Controlled Trials were explored for relevant reviews and trials, respectively. Guidance was categorised by the level of evidence, and "category of guideline" (i.e., "recommendation", "suggestion" or "no guideline possible").

RESULTS

Twelve generic suggestions (level of evidence - 5), three problem-specific recommendations and 14 problem-specific suggestions were generated. The generic suggestions relate to oral hygiene measures, assessment of problems, principles of management, re-assessment of problems and the role of dental/oral medicine professionals.

CONCLUSIONS

This guidance provides a framework for the management of common oral problems in patients with advanced cancer, although every patient requires individualised management.

The impact of tumor immunogenicity on cancer pain phenotype using syngeneic oral cancer mouse models

Head and neck squamous cell carcinoma (HNSCC) patients report severe function-induced pain at the site of the primary tumor. The current hypothesis is that oral cancer pain is initiated and maintained in the cancer microenvironment due to secretion of algogenic mediators from tumor cells and surrounding immune cells that sensitize the primary sensory neurons innervating the tumor. Immunogenicity, which is the ability to induce an adaptive immune response, has been widely studied using cancer cell transplantation experiments. However, oral cancer pain studies have primarily used xenograft transplant models in which human-derived tumor cells are inoculated in an athymic mouse lacking an adaptive immune response; the role of inflammation in oral cancer-induced nociception is still unknown. Using syngeneic oral cancer mouse models, we investigated the impact of tumor cell immunogenicity and growth on orofacial nociceptive behavior and oral cancer-induced sensory neuron plasticity. We found that an aggressive, weakly immunogenic mouse oral cancer cell line, MOC2, induced rapid orofacial nociceptive behavior in both male and female C57Bl/6 mice. Additionally, MOC2 tumor growth invoked a substantial injury response in the trigeminal ganglia as defined by a significant upregulation of injury response marker ATF3 in tongue-innervating trigeminal neurons. In contrast, using a highly immunogenic mouse oral cancer cell line, MOC1, we found a much slower onset of orofacial nociceptive behavior in female C57Bl/6 mice only as well as sex-specific differences in the tumor-associated immune landscape and gene regulation in tongue innervating sensory neurons. Together, these data suggest that cancer-induced nociceptive behavior and sensory neuron plasticity can greatly depend on the immunogenic phenotype of the cancer cell line and the associated immune response.

Oral squamous cell carcinoma-released brain-derived neurotrophic factor contributes to oral cancer pain by peripheral tropomyosin receptor kinase B activation

ABSTRACT

Oral cancer pain is debilitating and understanding mechanisms for it is critical to develop novel treatment strategies treatment strategies. Brain-derived neurotrophic factor (BDNF) signaling is elevated in oral tumor biopsies and is involved with tumor progression. Whether BDNF signaling in oral tumors contributes to cancer-induced pain is not known. The current study evaluates a novel peripheral role of BDNF-tropomyosin receptor kinase B (TrkB) signaling in oral cancer pain. Using human oral squamous cell carcinoma (OSCC) cells and an orthotopic mouse tongue cancer pain model, we found that BDNF levels were upregulated in superfusates and lysates of tumor tongues and that BDNF was expressed by OSCC cells themselves. Moreover, neutralization of BDNF or inhibition of TrkB activity by ANA12, within the tumor-bearing tongue reversed tumor-induced pain-like behaviors in a sex-dependent manner. Oral squamous cell carcinoma conditioned media also produced pain-like behaviors in naïve male mice that was reversed by local injection of ANA12. On a physiological level, using single-fiber tongue-nerve electrophysiology, we found that acutely blocking TrkB receptors reversed tumor-induced mechanical sensitivity of A-slow high threshold mechanoreceptors. Furthermore, single-cell reverse transcription polymerase chain reaction data of retrogradely labeled lingual neurons demonstrated expression of full-form TrkB and truncated TrkB in distinct neuronal subtypes. Last but not the least, intra-TG siRNA for TrkB also reversed tumor-induced orofacial pain behaviors. Our data suggest that TrkB activities on lingual sensory afferents are partly controlled by local release of OSCC-derived BDNF, thereby contributing to oral cancer pain. This is a novel finding and the first demonstration of a peripheral role for BDNF signaling in oral cancer pain.

Allicin Could Potentially Alleviate Oral Cancer Pain by Inhibiting "Pain Mediators" TNF-alpha, IL-8, and Endothelin

To evaluate the effects of allicin on mediators of pain secreted by oral cancer cells in vitro, single-cell suspensions were prepared by enzymatic method from oral squamous cell carcinoma (OSCC). Cancer stem cells were isolated by the CD133+ selection method with magnetic cell sorting. Stemness markers were checked in both cancer cells and cancer stem cells by RT-PCR. Comparative analysis of pain mediators TNF-alpha, IL-8, and endothelin at both RNA and protein levels for normal epithelial cells, cancer cells, and cancer stem cells was carried out with and without allicin treatment. CD133 and CD44 expression levels were checked in cancer cells and cancer stem cells flow cytometrically. Allicin inhibited both gene and protein expression of TNF-alpha, IL-8, and endothelin in both cancer cells and cancer stem cells. Allicin is more likely to be a promising treatment in alleviating the levels of pain and inflammation in OSCCs.

Temporomandibular disorders in head and neck cancers: Overview of specific mechanisms and management

Diagnosis classification system of Temporomandibular disorders (TMD) is based on the biopsychosocial model of pain. The pathogenesis is poorly understood, leading to difficulties in treating these multifactorial conditions. The predisposing factors are pathophysiological, psychological or structural processes that alter the masticatory system and lead to an increase in the risk of development of TMD. The purpose of this integrative review was then to point out the specific mechanisms of TMD in the oral oncologic context to optimize the TMJ functional results in the management of patients with oral oncologic conditions. We explored in this paper the role of Axis II assessment of the biopsychosocial model of pain, the involvement of mechanical concepts such as dental occlusion, mandibular condyle positioning and related-structures reconstruction, and the stomatognathic changes induced by radiation.

Targeted cancer therapies: Oral health care implications

BACKGROUND

Targeted treatments have been incorporated into oncology protocols, often with more traditional therapies, and are not totally free of adverse reactions, some of which affect the orofacial region.

METHODS

The authors searched PubMed, the Cochrane Library, and the US Food and Drug Administration Approved Drug Products database to identify reported adverse effects of targeted agents in the orofacial region as well as other implications in oral health care. Their principal focus was the relatively newer category of molecularly targeted drugs which are called small molecules (SMs).

RESULTS

The authors identified several categories of SMs and biological agents (for example, monoclonal antibodies) with adverse effects in the orofacial region. The oral and perioral regions are also fields for which there are therapeutic applications for targeted therapies, particularly to treat malignant neoplasms such as head and neck cancers.

CONCLUSIONS

SMs are the most rapidly growing group of targeted cancer treatments. Patients receiving SMs and other targeted antineoplastic agents may require oral medicine advice and special-care dentistry.

PRACTICAL IMPLICATIONS

In this narrative review, the authors focus mainly on the orofacial adverse effects of targeted cancer therapies and outline many of the agents that are in use so the dentally focused reader can familiarize themselves with these adverse effects and agents.

Oral Pain in the Cancer Patient

Oral pain due to cancer and associated treatments is common. The prevalence and severity of oral cancer is high. Painful oral mucositis develops in head and neck cancer patients following surgery and associated radiation therapy and/or chemotherapy. In addition, oral pain, including pain from mucositis, occurs in patients receiving chemotherapy for cancers of the hematopoietic system and cancers at other anatomic sites. Despite pain management practices that include high-dose opioid analgesics, patients rarely obtain relief from either head and neck cancer pain or mucositis pain. Because oral pain in cancer patients is likely due to both nociceptive and neuropathic mechanisms, effective management of pain requires treatments for both processes. As knowledge of the pathophysiology of oral pain in cancer patients increases, new approaches for the prevention and management are anticipated. This article focuses on the emerging evidence that supports the molecular mechanisms and the unique oral micro-neuroanatomy that in combination produce the severe oral pain experienced by cancer patients. In addition, this article summarizes the current state of clinical management of oral mucositis pain.

The point of pain in head and neck cancer

Head and neck cancer (HNC) can have a devastating impact on patient's lives as both disease and treatment may affect the ability to speak, swallow and breathe. These conditions limit the oral intake of food and drugs, reduce social functioning and impact on patient's quality of life. Up to 80% of patients suffering from HNC have pain due to the spread of the primary tumor, because of consequences of surgery, or by developing oral mucositis, dysphagia or neuropathy as toxic side effects of radiotherapy, chemotherapy or both. All healthcare professionals caring for HNC patients should assess palliative and supportive care needs in initial treatment planning and throughout the disease, with awareness when specialist palliative care expertise is needed. This paper focuses on assessment, characterizations and clinical management of pain in advanced HNC patients undergoing surgery, chemotherapy and radiotherapy, also underlining the importance of symptom assessment in HNC survivors and the need of clinical research in this field.

Depiction of Oral Tumor-Induced Trigeminal Afferent Responses Using Single-Fiber Electrophysiology

Considerable gap in knowledge exists about the mechanisms by which oral tumors regulate peripheral sensory fibers to produce pain and altered sensations. To address this gap, we used a murine model of oral squamous cell carcinoma (OSCC) of the tongue to investigate changes in response properties of trigeminal afferent neurons. Using this model, we developed an ex vivo method for single neuron recordings of the lingual nerve from isolated tongue tissue. Our data demonstrated that the tongue tumor produced increased spontaneous firing of lingual fibers compared to control as well as produced mechanical hypersensitivity and reduced von Frey thresholds of C- and A-slow-high-threshold mechanoreceptors (HTMR) fibers but had no effect on C-LTMR, A-slow-LTMR and A-fast lingual fibers. Mechanically-insensitive fibers were also detected in lingual afferents of the control group, that were significantly decreased in tumor-bearing preparations. Collectively, using single fiber electrophysiology of lingual sensory fibers, we show that human OSCC tumors sensitize peripheral trigeminal nerve terminals, providing a unique opportunity to study mechanisms of oral cancer pain.

Cancer Pain, Anxiety, and Depression in Admitted Patients at a Tertiary Care Hospital: A Prospective Observational Study

Context:

Pain is the most common symptom in admitted cancer patients. The association between the severity of cancer pain and distress symptoms such as depression and anxiety is a subject of research.

Aims:

The aim is to study the prevalence of pain, anxiety, and depression in admitted cancer patients and determine the association between pain and anxiety and depression at a tertiary cancer care institute.

Settings and Design:

This was prospective observational study.

Subjects and Methods:

We enrolled 393 cancer inpatients prospectively after written informed consent. Their disease details, presence, severity, and character of pain were recorded. Numerical Pain Scale was used for pain scores, self-reporting Hospital Anxiety and Depression Scale for anxiety and depression.

Statistical Analysis Used:

Normal data were analyzed with parametric, nonnormal with nonparametric methods, and categorical with the Chi-square test.

Results:

The prevalence of moderate-to-severe pain was 41.5%, anxiety 20.3%, and depression 24.8%. Proportion of patients with anxiety and depression was 9.2% and 17.7% in patients with no pain; about 32.8% and 36.7% with severe pain, respectively (P < 0.000). In patients with no depression 6% had anxiety; with depression 44.9% had anxiety (P < 0.000). Odd's ratio to have anxiety and depression was 4.44 (95% confidence interval [CI] 2.0318–9.7024) and 2.92 (95% CI 1.5739–5.4186), respectively, in patients with pain as compared to no pain (P < 0.00). There was a positive correlation between pain, anxiety, and depression scores.

Conclusions:

There is strong association between the presence and severity of pain and distress symptoms such as anxiety and depression in admitted cancer patients.

Anti-cancer and analgesic effects of resolvin D2 in oral squamous cell carcinoma

Oral cancer is often painful and lethal. Oral cancer progression and pain may result from shared pathways that involve unresolved inflammation and elevated levels of pro-inflammatory cytokines. Resolvin D-series (RvDs) are endogenous lipid mediators derived from omega-3 fatty acids that exhibit pro-resolution and anti-inflammatory actions. These mediators have recently emerged as a novel class of therapeutics for diseases that involve inflammation; the specific roles of RvDs in oral cancer and associated pain are not defined. The present study investigated the potential of RvDs (RvD1 and RvD2) to treat oral cancer and alleviate oral cancer pain. We found down-regulated mRNA levels of GPR18 and GPR32 (which code for receptors RvD1 and RvD2) in oral cancer cells. Both RvD1 and RvD2 inhibited oral cancer proliferation in vitro. Using two validated mouse oral squamous cell carcinoma xenograft models, we found that RvD2, the more potent anti-inflammatory lipid mediator, significantly reduced tumor size. The mechanism of this action might involve suppression of IL-6, C-X-C motif chemokine 10 (CXCL10), and reduction of tumor necrosis. RvD2 generated short-lasting analgesia in xenograft cancer models, which coincided with decreased neutrophil infiltration and myeloperoxidase activity. Using a cancer supernatant model, we demonstrated that RvD2 reduced cancer-derived cytokines/chemokines (TNF-α, IL-6, CXCL10, and MCP-1), cancer mediator-induced CD11b⁺Ly6G^- myeloid cells, and nociception. We infer from our results that manipulation of the endogenous pro-resolution pathway might provide a novel approach to improve oral cancer and cancer pain treatment.

Alterations in opioid inhibition cause widespread nociception but do not affect anxiety-like behavior in oral cancer mice

Widespread pain and anxiety are commonly reported in cancer patients. We hypothesize that cancer is accompanied by attenuation of endogenous opioid-mediated inhibition, which subsequently causes widespread pain and anxiety. To test this hypothesis we used a mouse model of oral squamous cell carcinoma (SCC) in the tongue. We found that mice with tongue SCC exhibited widespread nociceptive behaviors in addition to behaviors associated with local nociception that we reported previously. Tongue SCC mice exhibited a pattern of reduced opioid receptor expression in the spinal cord; intrathecal administration of respective mu (MOR), delta (DOR), and kappa (KOR) opioid receptor agonists reduced widespread nociception in mice, except for the fail flick assay following administration of the MOR agonist. We infer from these findings that opioid receptors contribute to widespread nociception in oral cancer mice. Despite significant nociception, mice with tongue SCC did not differ from sham mice in anxiety-like behaviors as measured by the open field assay and elevated maze. No significant differences in c-Fos staining were found in anxiety-associated brain regions in cancer relative to control mice. No correlation was found between nociceptive and anxiety-like behaviors. Moreover, opioid receptor agonists did not yield a statistically significant effect on behaviors measured in the open field and elevated maze in cancer mice. Lastly, we used an acute cancer pain model (injection of cancer supernatant into the mouse tongue) to test whether adaptation to chronic pain is responsible for the absence of greater anxiety-like behavior in cancer mice. No changes in anxiety-like behavior were observed in mice with acute cancer pain.

Head and Neck Cancer Pain

Pain is a significant morbidity resulting from head and neck cancer. Pain may also be the result of the treatments directed against head and neck cancer. An experienced practitioner may manage this pain by understanding the multifactorial mechanisms of pain and the various pharmacotherapies available. Pain should be managed with multiple medications in a multimodal approach, and nonpharmacologic therapies should be considered as well.

Comparison of orofacial pain of patients with different stages of precancer and oral cancer

Orofacial pain impairs a patient's speech, swallowing, eating and interpersonal relations. Thirty-seven patients with a premalignant oral lesion, 124 patients with oral squamous cell carcinoma (OSSC), and 21 patients with a recurrence of OSSC were evaluated for their orofacial pain. The University of California San Francisco Oral Cancer Pain Questionnaire was administered to these patients at their initial visit, before they were prescribed analgesics for pain and before any treatment. Significant differences with respect to orofacial pain between the groups could be evaluatedwere observed. Patients with recurrence had the highest facial pain and patients with precancer had the lowest. Patients with OSSC and recurrence of OSSC reported significant levels of orofacial pain and functional restriction because of pain. Moreover, patients with recurrence of OSSC experienced significantly higher function-related pain, rather than pain qualities. These findings suggest that an important predictor for recurrence of OSSC may be the onset of orofacial pain that is exacerbated during function. The present study examined orofacial pain depending on the disease severity of precancer and oral cancer patients. Earlier recognition of symptoms of OSSC may improve early detection of its recurrence.

Management of Skull Base Tumor-Associated Facial Pain

Cancer-associated facial pain can be caused by a variety of pathologic conditions. Here the authors describe the symptoms and incidence of facial pain secondary to three separate anatomic subcategories of cancer. The authors subsequently discuss the effectiveness and drawbacks of the most common methods of treatment.

Cancer and orofacial pain

BACKGROUND

Cancer pain is a devastating condition. Pain in the orofacial region, may be present as the single symptom of cancer or as a symptom of cancer in its later stages. This manuscript revises in a comprehensive manner the content of the conference entitled "Orofacial Pain and Cancer" (Dolor Orofacial y Cancer) given at the VI Simposio International "Advances in Oral Cancer" on the 22 July, 2016 in San Sebastioan-Donostia, Spain.

MATERIAL AND METHODS

We have reviewed (pubmed-medline) from the most relevant literature including reviews, systematic reviews and clinical cases, the significant and evidence-based mechanisms and mediators of cancer-associated facial pain, the diverse types of cancers that can be present in the craniofacial region locally or from distant sites that can refer to the orofacial region, cancer therapy that may induce pain in the orofacial region as well as discussed some of the new advancements in cancer pain therapy.

RESULTS

There is still a lack of understanding of cancer pain pathophysiology since depends of the intrinsic heterogeneity, type and anatomic location that the cancer may present, making more challenging the creation of better therapeutic options. Orofacial pain can arise from regional or distant tumor effects or as a consequence of cancer therapy.

CONCLUSIONS

The clinician needs to be aware that the pain may present the characteristics of any other orofacial pain disorder so a careful differential diagnosis needs to be given. Cancer pain diagnosis is made by exclusion and only can be reached after a thorough medical history, and all the common etiologies have been carefully investigated and ruled out. The current management tools are not optimal but there is hope for new, safer and effective therapies coming in the next years.

Oral and dental health in head and neck cancer survivors

Therapeutic improvements and epidemiologic changes in head and neck cancer (HNC) over the last three decades have led to increased numbers of survivors, resulting in greater need for continuing management of oral and dental health in this population. Generally, the HNC patient oral health needs are complex, requiring multidisciplinary collaboration among oncologists and dental professionals with special knowledge and training in the field of oral oncology. In this review, we focus on the impact of cancer treatment on oral health, and the oral care protocols recommended prior to, during and after cancer therapy. The management of oral complications such as mucositis, pain, infection, salivary function, taste and dental needs are briefly reviewed. Other complications and their management, including osteonecrosis of the jaw and recurrent/new primary malignancies are also described. This review offers clinical protocols and information for medical providers to assist in understanding oral complications and their management in HNC patients and survivors, and their oral and dental health care needs. Oral and dental care is impacted by the patient's initial oral and dental status, as well as the specific cancer location, type, and its treatment; thus, close communication between the dental professional and the oncology team is required for appropriate therapy.

Cancer and Referred Facial Pain

Orofacial pain may be a symptom of diverse types of cancers as a result of local or distant tumor effects. The pain can be presented with the same characteristics as any other orofacial pain disorder, and this should be recognized by the clinician. Orofacial pain also can arise as a consequence of cancer therapy. In the present article, we review the mechanisms of cancer-associated facial pain, its clinical presentation, and cancer therapy associated with orofacial pain.

Supportive Management of Mucositis and Metabolic Derangements in Head and Neck Cancer Patients

Oral mucositis (OM) is among the most undesirable, painful, and expensive toxicities of cytotoxic cancer therapy, and is disheartening for patients and frustrating for caregivers. Accurate assessment of the incidence of OM has been elusive, but accumulating data suggests that reported OM frequency is significantly less than its actual occurrence. It has been suggested that over 90% of head and neck cancer (HNC) patients receiving radiotherapy (RT) with concurrent cisplatin experience severe OM with symptoms of extreme pain, mucosal ulceration and consequent limitations in swallowing and achieving adequate nutritional intake. This panoply of symptoms inevitably impacts a patients' quality of life and their willingness to continue treatment. In spite of all the advances made in understanding the pathophysiology of OM, there is still no prophylactic therapy with proven efficacy. Strategies to limit the extent of OM and to manage its symptomatology include basic oral care, supportive medications, nutritional support and targeting aggressive treatments to high-risk patients. This review focuses on OM recognition, preventive measurements, and symptom-management strategies.

Symptoms Reported by Head and Neck Cancer Patients during Radiotherapy and Association with Mucosal Ulceration Site and Size: An Observational Study

Background

Self-reported pain and impairment of oral functions varies markedly and often in spite of extensive oral mucositis (OM). The aim of the current study was to appraise how patient-reported debilitation caused by OM is influenced by the extent and possibly location of the OM lesions.

Methods

Patients with head and neck cancer undergoing radiotherapy were examined before treatment, twice weekly during 6-7 weeks of therapy, and 3-4 weeks after therapy completion. OM signs of 33 participants were evaluated using the Oral Mucositis Assessment Scale (OMAS), while OM symptoms were recorded using Patient-Reported Oral Mucositis Symptom (PROMS)-questionnaires. Changes in OM experience as a function of OM signs was undertaken by comparing the aggregated and individual PROMS scale values at the point of transition of OMAS ulceration scores between 0 to 1, 1 to 2 and 2 to 3, respectively in the nine intra-oral locations designated in the OMAS. ANOVA with pairwise contrasts using the LSD procedure was applied for comparisons of mean changes of PROMS scale values for the participants who experienced an OMAS score of 2 or more during therapy (n=24).

Results

Impairment of eating hard foods was more when the OMAS score for ulceration anywhere in the mouth or in the soft palate changed from 1 to 2, compared to between score 0 and 1 (p=.002 and p=.05) or between score 2 and 3 (p=.001 and p=.02). Mouth pain increased more upon transition of OMAS score anywhere in the mouth from 1 to 2 compared to 0 to 1 (p=.05).

Conclusion

The relationship between patient-reported impairment of oral function and pain caused by OM ulceration is not linear, but rather curvilinear. Our findings should prompt investigators of future interventional trials to consider using a less severe outcome than maximum OM scores as the primary study outcome.

Basic oral care for hematology-oncology patients and hematopoietic stem cell transplantation recipients: a position paper from the joint task force of the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) and the European Society for Blood and Marrow Transplantation (EBMT)

PURPOSE

Hematology-oncology patients undergoing chemotherapy and hematopoietic stem cell transplantation (HSCT) recipients are at risk for oral complications which may cause significant morbidity and a potential risk of mortality. This emphasizes the importance of basic oral care prior to, during and following chemotherapy/HSCT. While scientific evidence is available to support some of the clinical practices used to manage the oral complications, expert opinion is needed to shape the current optimal protocols.

METHODS

This position paper was developed by members of the Oral Care Study Group, Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) and the European Society for Blood and Marrow Transplantation (EBMT) in attempt to provide guidance to the health care providers managing these patient populations.

RESULTS

The protocol on basic oral care outlined in this position paper is presented based on the following principles: prevention of infections, pain control, maintaining oral function, the interplay with managing oral complications of cancer treatment and improving quality of life.

CONCLUSION

Using these fundamental elements, we developed a protocol to assist the health care provider and present a practical approach for basic oral care. Research is warranted to provide robust scientific evidence and to enhance this clinical protocol.

Adenosine triphosphate drives head and neck cancer pain through P2X2/3 heterotrimers

Introduction

Cancer pain creates a poor quality of life and decreases survival. The basic neurobiology of cancer pain is poorly understood. Adenosine triphosphate (ATP) and the ATP ionotropic receptor subunits, P2X2 and P2X3, mediate cancer pain in animal models; however, it is unknown whether this mechanism operates in human, and if so, what the relative contribution of P2X2- and P2X3-containing trimeric channels to cancer pain is. Here, we studied head and neck squamous cell carcinoma (HNSCC), which causes the highest level of function-induced pain relative to other types of cancer.

Results

We show that the human HNSCC tissues contain significantly increased levels of ATP compared to the matched normal tissues. The high levels of ATP are secreted by the cancer and positively correlate with self-reported function-induced pain in patients. The human HNSCC microenvironment is densely innervated by nerve fibers expressing both P2X2 and P2X3 subunits. In animal models of HNSCC we showed that ATP in the cancer microenvironment likely heightens pain perception through the P2X2/3 trimeric receptors. Nerve growth factor (NGF), another cancer-derived pain mediator found in both human and mouse HNSCC, induces P2X2 and P2X3 hypersensitivity and increases subunit expression in murine trigeminal ganglion (TG) neurons.

Conclusions

These data identify a key peripheral mechanism in cancer pain and highlight the clinical potential of specifically targeting nociceptors expressing both P2X2 and P2X3 subunits (e.g., P2X2/3 heterotrimers) to alleviate cancer pain.

Electronic supplementary material

The online version of this article (doi:10.1186/2051-5960-2-62) contains supplementary material, which is available to authorized users.

Predictors of long-term opioid treatment among patients who receive chemoradiation for head and neck cancer

INTRODUCTION

The factors associated with successful opioid discontinuation after cancer treatment are not well-known. We determined the proportion of patients with advanced head and neck cancer who continued using opioids 3 months after the completion of radiation therapy with or without chemotherapy.

METHODS

We included 70 patients with head and neck cancer referred to our institution's supportive care center between January 1, 2008, and December 31, 2010. Patients who no longer used opioids 3 months after the completion of radiation therapy were classified as stoppers; patients who continued using opioids were considered nonstoppers. We compared demographics, cancer-related characteristics, alcoholism, substance abuse history, use of psychoactive drugs, and opioid-related factors between stoppers and nonstoppers.

RESULTS

In all, 44 of 70 patients (63%) and 23 of 70 patients (33%) continued opioids 3 months and 6 months after the completion of radiation therapy, respectively. A total of 18 of 44 nonstoppers (41%) and 3 of 26 stoppers (12%) were positive for alcoholism based on the CAGE questionnaire (i.e., Cut down, Annoying, Guilty, Eye opener; odds ratio: 5.3). Demographic and clinical characteristics did not differ between stoppers and nonstoppers. The median duration of any type of opioid use of CAGE-positive patients was significantly longer than that of CAGE-negative patients (median: 261 days vs. 93 days; hazard ratio: 2.5).

CONCLUSION

CAGE positivity is a risk factor for opioid use beyond 3 months after the completion of radiation therapy and for duration of opioid treatment. Routine CAGE screening and meticulous follow-up are needed for these patients.

An investigation of the effect of tailored information on symptoms of anxiety and depression in Head and Neck cancer patients

OBJECTIVE

To investigate if tailored information provision decreases symptoms of anxiety and depression in late stage Head and Neck (H&N) cancer patients.

METHODS

This non-randomized, controlled trial was conducted with stage III or IV H&N cancer patients. Subjects were recruited at two academic health centers in Montreal. At the test center, subjects received the Multimode Comprehensive Tailored Information Package (MCTIP), while at the control center, they received normal information provision. Participants were evaluated using the Hospital Anxiety and Depression Scale (HADS) at baseline and 3 and 6 month later. Data were analyzed using descriptive statistics then T tests and chi square tests to compare group differences and finally mixed model analysis to test differences in outcome variables.

RESULTS

A total of 103 subjects were recruited and of them 96 (47 tests and 49 controls) participants completed baseline, 3 and 6 month evaluations. The test group experienced lower levels of anxiety (p = 0.001) and depression (p = 0.089) than the control group.

CONCLUSION

The subjects receiving tailored information had lower levels of anxiety than their counterparts. In addition, depression showed a reduction in the expected direction in the test group.

PRACTICE IMPLICATIONS

Our results need to be further confirmed using a randomized approach in different samples but they suggest benefits for stage III and IV H&N cancer patients receiving tailored, multi-modal information concerning their cancer.

Oral complications of cancer and cancer therapy: from cancer treatment to survivorship

Answer questions and earn CME/CNE Oral complications resulting from cancer and cancer therapies cause acute and late toxicities that may be underreported, underrecognized, and undertreated. Recent advances in cancer treatment have led to changes in the incidence, nature, and severity of oral complications. As the number of survivors increases, it is becoming increasingly recognized that the aggressive management of oral toxicities is needed to ensure optimal long-term oral health and general well-being. Advances in care have had an impact on previously recognized oral complications and are leading to newly recognized adverse effects. Here, the authors briefly review advances in cancer therapy, including recent advances in surgery, oral care, radiation therapy, hematopoietic cell transplantation, and medical oncology; describe how these advances affect oral health; and discuss the frequent and/or severe oral health complications associated with cancer and cancer treatment and their effect upon long-term health. Although some of the acute oral toxicities of cancer therapies may be reduced, they remain essentially unavoidable. The significant impact of long-term complications requires increased awareness and recognition to promote prevention and appropriate intervention. It is therefore important for the primary oncologist to be aware of these complications so that appropriate measures can be implemented in a timely manner. Prevention and management is best provided via multidisciplinary health care teams, which must be integrated and communicate effectively in order to provide the best patient care in a coordinated manner at the appropriate time.

Analgesia targeting IB4-positive neurons in cancer-induced mechanical hypersensitivity

Cancer patients often suffer from pain and most will be prescribed μ-opioids. μ-opioids are not satisfactory in treating cancer pain and are associated with multiple debilitating side effects. Recent studies show that μ and δ opioid receptors are separately expressed on IB4 (-) and IB4 (+) neurons, which control thermal and mechanical pain, respectively. In this study we investigated IB4 (+) and IB4 (-) neurons in mechanical and thermal hypersensitivity in an orthotopic mouse oral cancer model. We used a δ opioid receptor agonist and a P2X(3) antagonist to target IB4 (+) neurons and to demonstrate that this subset plays a key role in cancer-induced mechanical allodynia, but not in thermal hyperalgesia. Moreover, selective removal of IB4 (+) neurons using IB4-saporin impacts cancer-induced mechanical but not thermal hypersensitivity. Our results demonstrate that peripherally administered pharmacological agents targeting IB4 (+) neurons, such as a selective δ-opioid receptor agonist or P2X(3) antagonist, might be useful in treating oral cancer pain.

PERSPECTIVE

To clarify the mechanisms of oral cancer pain, we examined the differential role of IB4 (+) and IB4 (-) neurons. Characterization of these 2 subsets of putative nociceptors is important for further development of effective clinical cancer pain relief.

Management of cancer therapy-induced oral mucositis

The oral mucosa is a common site for collateral damage of cancer therapies, including radiation, cytotoxic medication, and newer targeted therapies. Ulcerative oral mucositis is typically painful and affects oral functions including speech, and oral intake of food and medications, thus impacting the quality of life. Denuded epithelium may also provide access of oral microbial flora to the deeper tissues and the circulation. Prevention of oral mucositis is an ongoing quest currently with relatively few answers. In this chapter, the present authors discuss the evidence and current practice for prophylaxis and management of this treatment side effect in cancer patients.

Biologic mechanisms of oral cancer pain and implications for clinical therapy

Cancer pain is an ever-present public health concern. With innovations in treatment, cancer patients are surviving longer, but uncontrollable pain creates a poor quality of life for these patients. Oral cancer is unique in that it causes intense pain at the primary site and significantly impairs speech, swallowing, and masticatory functions. We propose that oral cancer pain has underlying biologic mechanisms that are generated within the cancer microenvironment. A comprehensive understanding of key mediators that control cross-talk between the cancer and peripheral nervous system, and possible interventions, underlies effective cancer pain management. The purpose of this review is to explore the current studies on oral cancer pain and their implications in clinical management for cancer pain in general. Furthermore, we will explore the endogenous opioid systems and novel cancer pain therapeutics that target these systems, which could solve the issue of opiate tolerance and improve quality of life in oral cancer patients.

Nerve growth factor links oral cancer progression, pain, and cachexia

Cancers often cause excruciating pain and rapid weight loss, severely reducing quality of life in cancer patients. Cancer-induced pain and cachexia are often studied and treated independently, although both symptoms are strongly linked with chronic inflammation and sustained production of proinflammatory cytokines. Because nerve growth factor (NGF) plays a cardinal role in inflammation and pain, and because it interacts with multiple proinflammatory cytokines, we hypothesized that NGF acts as a key endogenous molecule involved in the orchestration of cancer-related inflammation. NGF might be a molecule common to the mechanisms responsible for clinically distinctive cancer symptoms such as pain and cachexia as well as cancer progression. Here we reported that NGF was highly elevated in human oral squamous cell carcinoma tumors and cell cultures. Using two validated mouse cancer models, we further showed that NGF blockade decreased tumor proliferation, nociception, and weight loss by orchestrating proinflammatory cytokines and leptin production. NGF blockade also decreased expression levels of nociceptive receptors TRPV1, TRPA1, and PAR-2. Together, these results identified NGF as a common link among proliferation, pain, and cachexia in oral cancer. Anti-NGF could be an important mechanism-based therapy for oral cancer and its related symptoms.

Clinical practice guidelines for the prevention and treatment of EGFR inhibitor-associated dermatologic toxicities

Background

Epidermal growth factor receptor inhibitors (EGFRI) produce various dermatologic side effects in the majority of patients, and guidelines are crucial for the prevention and treatment of these untoward events. The purpose of this panel was to develop evidence-based recommendations for EGFRI-associated dermatologic toxicities.

Methods

A multinational, interdisciplinary panel of experts in supportive care in cancer reviewed pertinent studies using established criteria in order to develop first-generation recommendations for EGFRI-associated dermatologic toxicities.

Results

Prophylactic and reactive recommendations for papulopustular (acneiform) rash, hair changes, radiation dermatitis, pruritus, mucositis, xerosis/fissures, and paronychia are presented, as well as general dermatologic recommendations when possible.

Conclusion

Prevention and management of EGFRI-related dermatologic toxicities is critical to maintain patients’ health-related quality of life and dose intensity of antineoplastic regimens. More rigorous investigation of these toxicities is warranted to improve preventive and treatment strategies.

Electronic supplementary material

The online version of this article (doi:10.1007/s00520-011-1197-6) contains supplementary material, which is available to authorized users.

Orofacial pain and predictors in oral squamous cell carcinoma patients receiving treatment

Surgical and radiation therapy for oral squamous cell carcinoma (OSCC) may generate orofacial pain. The aims of this study were to (1) characterize the pain experienced by people with orofacial pain, and (2) determine the factors associated with changes in orofacial pain in OSCC patients during the postoperative and post-radiation therapy periods. The study had a prospective longitudinal design with consecutive sampling. Seventy-two eligible patients were recruited from the outpatient department of otolaryngology, head and neck cancer, and radiation therapy of a medical center in northern Taiwan. A set of questionnaires was used for patient assessment, including the University of California San Francisco Oral Cancer Pain Questionnaire, Symptom Severity Scale, Hospital Anxiety and Depression Scale, and Karnofsky's Performance Status Index. Patients were assessed at two time points: 1 month after surgery (T1) and 1 month after completion of radiation treatment (T2). The findings showed that (1) patients reported moderate orofacial pain at both time points; (2) orofacial pain, oral function-related symptoms, and psychological distress were significantly higher at T1 than at T2; and (3) older age, eating difficulty, speech difficulty, and depression were significant predictors of orofacial pain. Oral rehabilitation and relaxation training may reduce orofacial pain in this patient population.

A systematic review of orofacial pain in patients receiving cancer therapy

PURPOSE

We present the findings of a structured systematic review of the literature assessing orofacial pain induced by malignant disease and/or its therapy (excluding mucositis). This evaluation of the literature published after the 1989 NIH Development Consensus conference on the oral complications of cancer therapies is an effort to assess the prevalence of pain, quality of life and economic impact, and management strategies for cancer therapy-induced orofacial pain.

METHODS

A systematic medical literature search was conducted with assistance from a research librarian in MEDLINE/PubMed and EMBASE databases for articles published between January 1, 1990 and December 31, 2008. Each study was independently assessed by two reviewers with expertise in the field of oral oncology.

RESULTS

Thirty-nine studies assessed pain in the head and neck region. The measure was commonly embedded in quality of life studies. Most of these studies described pain in head and neck cancer (HNC) patients, which therefore became the focus of the report. Pain is common in patients with HNC and is reported by approximately half of patients prior to cancer therapy, 81% during therapy, 70% at the end of therapy, and by 36% at 6 months after treatment. Pain is experienced beyond the 6-month period by approximately one third of patients and is typically more severe than pre-treatment cancer-induced pain.

CONCLUSIONS

This systematic review identified the presence of pain before cancer therapy, likely attributable to the cancer; an increase in pain during therapy and the common persistence of pain following cancer treatment. Continuing research should use validated tools to prospectively assess orofacial pain, its causes and pathophysiology, and its effect on quality of life and economic impact. Clinical trials of pain management in this setting are also warranted.

Oral mucositis

Mucosal damage is one of the most common adverse effects of radiotherapy and of cytotoxic therapy for cancer. With prevalence between 10% and 100%, depending of the cytotoxic regimen and patient-associated variables, this morbid condition represents a significant problem in oncology. In this paper we address oral mucositis and discuss its pathobiology, risk factors, impact and management in view of the most recent evidence. Despite of clear progress and the development of clinical guidelines, what we currently have to offer to patients to manage mucositis and oropharyngeal pain is still inadequate. Expansion of the knowledge of the pathogenesis of mucositis as well as a better insight into individual risk factors will provide opportunities to improve management strategies.

Health-related quality of life assessment in prospective trials of systemic cytotoxic chemotherapy for metastatic castration-resistant prostate cancer: which instrument we need?

Knowledge about psychological health of men with prostate cancer is still limited. HRQoL assessment adds value in symptom management by allowing a broader understanding of the impact of symptom management beyond the targeted symptom, on functioning, and on overall QoL. In this paper, the results of the commonly used HRQoL questionnaires in phase III randomized clinical trials of chemotherapy in metastatic castration-resistant prostate cancer has been discussed. An overview about symptom burden, treatments and HRQoL domains, a description of available HRQoL instruments used for patients with metastatic castration-resistant prostate cancer were reported. Finally, the characteristics of most commonly used HRQoL instruments were identified and compared. To provide better empirical justification for the selection of HRQoL instruments, head-to-head comparisons of them within the same studies are needed. Estimating a minimal important difference could be significant when interpreting trial results. The impact of HRQoL scores in clinical practice remains unclear; poor communication of clinical significance of the results and limited training of clinicians are the most important barriers to a widespread use of HRQoL questionnaires.

Differences between Orofacial Inflammation and Cancer Pain

Rat models of orofacial cancer exhibit both allodynia and hyperalgesia; however, it is unclear whether cancer-induced pain is secondary to cancer-induced inflammation. To address this question, we compared the effects of an anti-inflammatory drug, indomethacin, on pain and neurochemical changes in the medullary dorsal horn in orofacial inflammation and cancer models. Daily peripheral administration of indomethacin largely suppressed mechanical allodynia and thermal hyperalgesia in the inflammation model. The same procedure suppressed allodynia and hyperalgesia in the cancer model, but the suppression was weak when compared with that in the inflammation model. In the medullary dorsal horn, calcitonin gene-related peptide and substance P levels were significantly increased in the inflammation model, but did not change in the cancer model. These results suggest that pain in the orofacial cancer model is not significantly mediated by cancer-induced peripheral inflammation, although it may have some involvement.

Pain is associated with an endophytic cancer growth pattern in patients with oral squamous cell carcinoma before treatment

The origins and mechanisms of pain arising from oral cancer are important. Oral cancer pain impairs a patient's quality of life. This study was undertaken to elucidate significant risk factors associated with spontaneous pain in patients with untreated oral squamous cell carcinoma (OSCC) before treatment. A total of 113 patients (82 men, 31 women; median age, 64 years) with untreated OSCC were examined. Correlations between spontaneous pain in the primary site and sex, age, primary site, TN stage, clinical stage, and clinical growth type of cancer (exophytic or endophytic), as well as the degree of histological differentiation and the histological mode of invasion were evaluated. At the initial examination, 42 (37%) of patients had spontaneous pain. In univariate statistical analyses, reported pain correlated significantly with patient age and the clinical growth type of the cancer, as well as with the degree of histological differentiation and the histological mode of invasion. Multiple logistic regression analysis showed significant correlations between reported spontaneous pain and the clinical growth type of the cancer (P = 0.0003; odds ratio, 9.5; 95% confidence interval, 2.8-32.3), as well as reported spontaneous pain and the histological mode of invasion (P = 0.0026; odds ratio, 4.7; 95% confidence interval, 1.7-12.7). Clinical and histological endophytic growth patterns of OSCC might be significant risk factors for the presence of spontaneous pain before treatment.

The role of pain in head and neck cancer recurrence and survivorship

OBJECTIVE

To examine pain, a common symptom in patients with head and neck cancer, and its relationship to recurrence and survivorship.

DESIGN

Prospective, observational study.

SETTING

Tertiary care institution.

PATIENTS

A total of 339 patients with head and neck carcinomas who participated in the Department of Otolaryngology's Outcomes Assessment Project between February 28, 1998, and November 30, 2001. Of 355 patients enrolled during this period, 7 were omitted from the study because they presented with persistent disease and 9 were omitted owing to a lack of valid pain data. Data on health-related quality of life were collected from the remaining patients at diagnosis and then at 3, 6, 9, and 12 months after diagnosis.

INTERVENTION

Administration of surveys and questionnaires.

MAIN OUTCOME MEASURES

The relationship of self-reported pain level with health-related quality of life during the first year, recurrence status, and 5-year disease-specific survivorship was determined through univariate and multivariate analyses.

RESULTS

Pain was associated with age, general physical and mental health conditions, depressive symptoms, survival rate, and recurrence within the first year. The 5-year survival rate was 81.8% for patients with low posttreatment pain and 65.1% for those with high pain. Posttreatment pain and tumor site were independent predictors of recurrence. Pain level, age, and treatment modality were independent predictors of 5-year survival.

CONCLUSION

Because of its association with recurrence and survival, pain within the first year of treatment for head and neck cancer is an important symptom that should be appropriately monitored and managed during routine follow-up.