Effects of radiotherapy on olfactory function

Effects of Radiation on Olfactory Function in Head and Neck Malignancy

OBJECTIVES

Olfactory dysfunction is an overlooked adverse effect of radiation therapy. This study is designed to find the effect of radiation therapy on olfactory function in head and neck malignancy excluding tumors of nose and nasopharynx and correlate the olfactory changes with the radiotherapy dose.

METHOD

This prospective observational study was done over a 2-year period in 34 participants with head and neck malignancies who underwent radiation therapy (RT). The participants olfaction was evaluated subjectively with Italian Nose Obstruction Symptom Evaluation (I-NOSE) scale and objectively by a modified I-Smell test which included an olfactory identification score and an olfactory threshold score at 5 time points. The beginning of RT (T0), at 2 weeks of RT(T1), end of RT (T2), 1 month follow-up (T3), and 3-month follow-up (T4). The near maximum dose to the nasal cavity (D2%) and mean dose to the nasal cavity (Dmean) were calculated for all participants and correlated with olfactory function.

RESULTS

A total of 34 patients with head neck malignancy were recruited. The median I-NOSE score reached maximum at the end of radiation and decreased to baseline at 3 months follow-up (P < .001). The olfactory identification score, olfactory threshold score, and median combined olfactory score showed a significant decrease at the end of radiation therapy compared to Pre-radiation therapy values. There was a significant but incomplete recovery in the 3-month follow-up period (P < .001).

CONCLUSION

There was a significant deterioration in quality of life for olfaction, olfactory identification, and olfactory threshold at the completion of radiotherapy. At 3 months follow-up, though there was no complete recovery of olfaction, it did not have an adverse effect on the quality of life.

Analgesic effect of linalool odor on oral ulcerative mucositis-induced pain in rats

Oral ulcerative mucositis (OUM) induces severe pain, leading to a low quality of life. Linalool odor exposure has recently been reported to suppress inflammatory pain in the hind paws. However, the analgesic effect of linalool odor on orofacial pain remains unclear. In this study, we examined the mechanism underlying the analgesic effect of linalool odor on oral pain caused by OUM using nocifensive behavioral and immunohistochemical analyses in rats. OUM was developed by treating the labial fornix region of the inferior incisors with acetic acid. Linalool at 1% was exposed for 5 min at 30 min before nocifensive behavioral measurements. OUM induced spontaneous pain and mechanical allodynia, which were suppressed by the linalool odor. Mechanical allodynia in the hind paw following the injection of complete Freund's adjuvant was also suppressed by linalool odor. Application of lidocaine to the olfactory bulb attenuated the inhibition of spontaneous pain and hyperactivation of trigeminal spinal nucleus caudalis neurons in OUM model rats. Linalool odor exposure-induced neuronal activation in the locus coeruleus (LC) of OUM model rats was decreased by lidocaine application to the olfactory bulb. The decrease in neuronal activation in the LC was attenuated by the administration of orexin 1 receptor (OX-1) antagonist to the LC. These results suggest that linalool odor stimulation through the olfactory pathway activates LC neurons via OX-1 signaling, leading to the suppression of OUM-induced oral pain.

Evaluation of sinonasal-related quality of life of 49 patients undergoing endoscopic skull base surgery

OBJECTIVE

This study aimed to evaluate the sinonasal-related Quality of Life (QoL) in patients undergoing endoscopic skull base surgery.

METHODS

A retrospective study was performed, including patients with benign and malignant tumors at a single institution. Each patient completed the 22-Item Sino-Nasal Outcome Test (SNOT-22) and the Empty Nose Syndrome 6 Item Questionnaires (ENS6Q) to assess their perceived QoL at least 2-months after treatment.

RESULTS

Forty-nine patients were enrolled in this study. The average score was 25.1 (Stander Deviation [SD] 14.99) for SNOT-22 and 6.51 (SD=5.58) for ENS6Q. Analysis of the overall results for the SNOT-22 showed that olfactory damage was the most serious syndrome. The most frequently reported high-severity sub-domains in SNOT-22 were nasal symptoms and sleep symptoms. Nasal crusting was the most severe item in ENS6Q according to the report. Nine patients (18.4%) had a score higher than 10.5 which indicates the high risk of Empty Nose Syndrome (ENS). SNOT-22 score was related to the history of radiotherapy (p< 0.05), while the ENS6Q score was not.

CONCLUSIONS

The possibility of patients suffering from ENS after nasal endoscopic skull base surgery is at a low level, although the nasal cavity structure is damaged to varying degrees. Meanwhile, patients undergoing endoscopic skull base surgery were likely to suffer nasal problems and sleep disorders. Patients who had received radiotherapy have a worse QoL than those without a history of radiotherapy.

LEVEL OF EVIDENCE

Level 3.

Current status of sinonasal cancer survivorship care

Sinonasal cancer is a heterogeneous orphan disease of diverse histologies, each with distinct clinical, oncologic, and toxicity profiles. Because of the comparative rarity of these cancers, sinonasal cancers are treated as a grouped diagnosis despite their clinical and biological heterogeneity. Multimodality treatment with a combination of surgery, chemotherapy, and/or radiotherapy is the standard-of-care for advanced-stage patients but there are few surveillance or follow-up practice guidelines or formalized survivorship care pathways. A scoping literature review was conducted via PubMed, EMBASE, and Google Scholar. A total of 112 studies were included, which were grouped along the following topics: surveillance, second primary tumors, quality of life, and symptom burden. Sinonasal cancer tends to exhibit a higher rate of local failure and occur in a delayed fashion compared to mucosal malignancies of the head and neck. Moreover, the site of failure and time-varying risk of recurrence is histology-specific. Following multimodality treatment of the skull base, patients may experience endocrine, visual, auditory, sinonasal, olfactory, and neurocognitive deficits, as well as psychosocial impairments that impact multiple physical and neuropsychological domains, resulting in diminished quality of life. Sinonasal cancer patients would benefit from tailored, histology-specific survivorship programs to address the recurrence, second primary, and functional impairments resulting from disease and treatment toxicity.

Olfactory Function and Olfactory Disorders

The sense of smell is important. This became especially clear to patients with infection-related olfactory loss during the SARS-CoV-2 pandemic. We react, for example, to the body odors of other humans. The sense of smell warns us of danger, and it allows us to perceive flavors when eating and drinking. In essence, this means quality of life. Therefore, anosmia must be taken seriously. Although olfactory receptor neurons are characterized by regenerative capacity, anosmia is relatively common with about 5 % of anosmic people in the general population. Olfactory disorders are classified according to their causes (e. g., infections of the upper respiratory tract, traumatic brain injury, chronic rhinosinusitis, age) with the resulting different therapeutic options and prognoses. Thorough history taking is therefore important. A wide variety of tools are available for diagnosis, ranging from short screening tests and detailed multidimensional test procedures to electrophysiological and imaging methods. Thus, quantitative olfactory disorders are easily assessable and traceable. For qualitative olfactory disorders such as parosmia, however, no objectifying diagnostic procedures are currently available. Therapeutic options for olfactory disorders are limited. Nevertheless, there are effective options consisting of olfactory training as well as various additive drug therapies. The consultation and the competent discussion with the patients are of major importance.

Sinonasal Side Effects of Chemotherapy and/or Radiation Therapy for Head and Neck Cancer: A Literature Review

Radiotherapy and chemotherapy represent important treatment modalities for head and neck cancer. Rhinosinusitis and smell alterations are common side effects in the sinonasal region. This review will summarize and analyze our current knowledge of the sinonasal side effects of chemotherapy and/or radiation therapy for head and neck cancer (HNC), with a specific focus on mucosal and olfactory disorders. A review of the English literature was performed using several databases (PubMed, Embase, Cochrane, Scopus). Fifty-six articles were included in qualitative synthesis: 28 assessed mucosal disorders (rhinitis or rhinosinusitis), 26 evaluated olfactory alterations, and 2 articles addressed both topics. The incidence and severity of olfactory dysfunction and chronic rhinosinusitis were highest at the end of radiotherapy and at three months after treatment and decreased gradually over time. Smell acuity deterioration and chronic rhinosinusitis seemed to be related to radiation dose on olfactory area and nasal cavities, but different degrees of recovery were observed. In conclusion, it is important to establish the severity of chronic rhinosinusitis and olfactory dysfunction in order to find strategies to support patients and improve their quality of life.

International consensus statement on allergy and rhinology: Olfaction

BACKGROUND

The literature regarding clinical olfaction, olfactory loss, and olfactory dysfunction has expanded rapidly over the past two decades, with an exponential rise in the past year. There is substantial variability in the quality of this literature and a need to consolidate and critically review the evidence. It is with that aim that we have gathered experts from around the world to produce this International Consensus on Allergy and Rhinology: Olfaction (ICAR:O).

METHODS

Using previously described methodology, specific topics were developed relating to olfaction. Each topic was assigned a literature review, evidence-based review, or evidence-based review with recommendations format as dictated by available evidence and scope within the ICAR:O document. Following iterative reviews of each topic, the ICAR:O document was integrated and reviewed by all authors for final consensus.

RESULTS

The ICAR:O document reviews nearly 100 separate topics within the realm of olfaction, including diagnosis, epidemiology, disease burden, diagnosis, testing, etiology, treatment, and associated pathologies.

CONCLUSION

This critical review of the existing clinical olfaction literature provides much needed insight and clarity into the evaluation, diagnosis, and treatment of patients with olfactory dysfunction, while also clearly delineating gaps in our knowledge and evidence base that we should investigate further.

Multidisciplinary approach to nose vestibule malignancies: setting new standards

Nose vestibule malignancies, mainly SCCs, are considered rare neoplasms. In the present paper, we review the current state of the art concerning classification and treatment, and describe current evidence supporting a paradigm shift. In the current AJCC classification nose vestibule is considered part of nasal cavity/ethmoid. In daily clinical practice, nose vestibule lesions are often misclassified as skin primaries. This leads to an underestimation of the real incidence and to a mis-management. When nose vestibule primaries are correctly classified as nose primaries, the current AJCC TNM appears inadequate for prognostic stratification and an old staging system described 4 decades ago by Wang has been demonstrated to be more reliable in the literature and is preferred in centers with the largest volume of cases treated. The principles of Wang classification should be applied and nose vestibule acknowledged as a new distinct subsite of nose and paranasal sinuses by the AJCC/UICC. Surgery, External Beam RadioTherapy (EBRT) and Interventional RadioTherapy (IRT, BrachyTherapy BT) are the current therapeutic options for nose vestibule (NV) SCC. Increasing evidence demonstrates that IRT, with a proper multidisciplinary approach, is at least equivalent to surgery and EBRT for treatment of the primary lesions in terms of oncological outcomes, but markedly superior in terms of cosmetic and functional results, supporting HDR (high dose rate) IRT as the new standard for the treatment of the primary lesion in these malignancies. To optimize the advantages of IRT as primary therapeutic modality we set up a new approach to the implantation phase of IRT exploiting the anatomic planes of esthetic and functional nose surgery and the potential of intensity modulated and image guided brachytherapy to avoid septal and alar perforation (anatomic implantation).

Functional results of exclusive interventional radiotherapy (brachytherapy) in the treatment of nasal vestibule carcinomas

PURPOSE

Surgery, external beam radiotherapy (EBRT), and interventional radiotherapy (IRT, BrachyTherapy BT) are the current therapeutic options for nose vestibule (NV) squamous cell carcinoma (SCC). In this article, we evaluate the nose functional parameters of patients affected by SCCs of the NV, primarily treated by interstitial IRT comparing them with healthy controls and with patients treated with intensity-modulated EBRT.

METHODS

Ten patients treated by using IRT (group 1), 10 healthy controls and eight patients treated by EBRT (group 2) on the region of the nose were submitted to clinical evaluation (with the NOSE scale score), rhinomanometry, olfactory testing, nasal citology, and evaluation of mucociliary clearance through saccharine test.

RESULTS

No long-term skin or cartilaginous toxicity are recorded. The olfactometry threshold discrimination identification TDI is lower in EB group. The mean NOSE scale score was significantly higher in group 2 than in group 1 and healthy controls (p < 0.05). The distribution of cytologic patterns resulted significantly different as well. Patients treated by EB have a significantly impaired mucociliary clearance, with a mean time for the transport of the stained marker, which is more than double in the patients treated by EB than in those treated with IRT (p < 0.001).

CONCLUSIONS

Nasal function and cytological findings are significantly better, substantially preserved, in patients treated by IRT than in those treated by EBRT, bringing new relevant evidence for the establishment of interstitial IRT as the new standard for the treatment of the primary lesion in cT1 and cT2 -Wang staging NV SCCs.

A multidimensional cohort study of late toxicity after intensity modulated radiotherapy for sinonasal cancer

PURPOSE

To evaluate the occurrence of late toxicity after curatively intended intensity modulated radiotherapy (IMRT) for sinonasal cancer and assess dose-response associations.

METHODS

Patients treated with IMRT in 2008-2016 were included. Cross sectional examinations of toxicity from the optic pathway, the brain, the pituitary gland and the nose were performed along with quality of life - (QoL) and dose-response analyses.

RESULTS

Twenty-seven patients were enrolled; median age was 67 years (range 47-83). Five patients (19%) had radiation-related ocular toxicity. The risk of visual acuity impairment increased with increasing dose (grade 2 odds ration (OR) 1.12, p = 0.01; grade 3 OR 1.14, p = 0.02) and dose constraint violations (grade 2, OR = 21, p < 0.01; grade 3, OR = 41, p < 0.01). Six patients (22%) exhibited evidence of radiation-related hypopituitarism, but no dose-response association was detected. Seventeen patients (63%) had impaired olfactory function. The risk of olfactory impairment increased with higher stage (OR = 3.32, p = 0.03). Three patients (11%) had structural abnormalities in irradiated areas of the brain, and impaired cognitive function was present in 17 patients (63%). Cognitive, physical, role functioning as well as fatigue and insomnia were affected the most in QOL analyses. Fifteen patients (56%) had grade 2 radiation-related impairment in at least one organ. Grade 3 toxicity was only present in patients with toxicities in >3 organs and in patients initially treated for T4 tumours. Three patients (11%) had radiation-related impaired function in all examined OARs.

CONCLUSION

Late toxicity after radiotherapy was substantial in all examined organs, with dose-response associations between visual acuity impairment and the optic nerve. The results have led to changed praxis for follow-up examinations in Denmark.

Effects of radiotherapy on olfaction and nasal function in head and neck cancer patients

PURPOSE

Radiotherapy (RT) is a major component of treatment in head and neck malignancies and often the radiation field includes the nasal cavity and olfactory cleft region. We aimed to assess olfaction, mucociliary clearance time and quality of life (QOL) before RT and during the course of radiotherapy.

METHODS

This prospective, observational, cohort study was conducted over a period of 1 year. The olfactory function, mucociliary clearance and QOL of patients with primary head and neck cancers undergoing radiation therapy as part of treatment were assessed prior to radiotherapy and followed up serially up to 3 months after radiotherapy. A total of 21 patients were enrolled. Assessment was done using noninvasive tests for better compliance and ease of examination.

RESULTS

Among the 21 patients recruited, 18 completed radiotherapy and 13 were assessed 3 months post radiotherapy. Mean olfactory scores (including olfactory threshold and odor identification), using Connecticut Chemosensory Clinical Research Center (CCCRC) test, deteriorated significantly at the end of radiotherapy (p < 0.001) as compared to scores before irradiation. Subjective assessment of olfaction by Appetite, Hunger and Sensory perception (AHSP) questionnaire did not demonstrate significant impairment in nasal function (p < 0.319) although overall QOL significantly deteriorated (p 0.004). The mucociliary clearance time was prolonged in 72% of the patients at the end of radiotherapy.

CONCLUSION

Deterioration in olfactory function was found to occur during the course of radiotherapy with gradual improvement after 3 months. However, patients did not notice olfactory dysfunction subjectively. Mucociliary dysfunction persisted even after 3 months following radiation.

Prospective assessment of gustatory function after radiotherapy for head and neck cancers

BACKGROUND

Taste disorders are major causes of morbidity in patients undergoing head and neck irradiation. We quantitatively assessed the gustatory function of patients with head and neck cancers who underwent radiotherapy using recently developed standardised tools for measuring taste.

METHODS

Twenty patients undergoing head and neck irradiation responded to a specific questionnaire and were assessed by olfactory and gustatory function tests. To assess changes over time, testing was performed before, immediately after, and at 2- and 4-week intervals following the start of radiotherapy. Concurrently, patients were evaluated for xerostomia from radiotherapy.

RESULTS

A decrease in the taste recognition threshold was observed in the second week after the beginning of radiotherapy. The taste detection threshold improved within the 14th-18th week. Most affected patients demonstrated that their gustatory function primarily decreased independent of the olfactory function. Disturbances in taste were exponentially worsened beyond an accumulated dose of 30 Gy and involved all tastants. According to a multivariate analysis, radiation-induced taste impairment was not influenced by the degree of xerostomia. However, there was an association between the dose of irradiation and the severity of taste disturbance.

CONCLUSIONS

In this preliminary study, we found that the taste function was worse 2 weeks after the start of radiotherapy and returned to pretreatment levels within 4.5 months. Taste disturbances were exponentially worse beyond an accumulated dose of 20 Gy. Taste dysfunction after radiotherapy was not influenced by the degree of xerostomia, whereas only the dose of irradiation was associated with the severity of taste dysfunction.

Radiation-Induced Rhinitis: Cytological and Olfactory Changes

BACKGROUND

Oral mucositis is a well-known adverse event of radiotherapy (RT) for head and neck cancer (HNC). Its nasal counterpart, the radiation-induced rhinitis, is poorly studied and considered in clinical practice.

OBJECTIVE

The aim of this observational study was to evaluate acute cytological and olfactory alterations during RT and their correlation with RT doses.

METHODS

Ten patients who underwent RT for HNC, excluding tumors of the nasal cavities, were evaluated with nasal scraping for cytological examination, Sniffin' Sticks test for olfactory assessment, and Nasal Obstruction Symptom Evaluation scale. The examinations were performed before (T0), at mid-course (T1), and at the end (T2) of RT. They were repeated 1 and 3 months after RT (T3 and T4). Mean dose (D_mean) and near maximum dose (D_2%) to nasal cavities and inferior turbinates were used for correlation analyses.

RESULTS

Radiation-induced rhinitis was present in 70% of patients at T2, and it was still observed in 40% of cases after 3 months. Although olfactory function remained within the normal range at the evaluated times, a significant decrease in odor threshold and discrimination was observed during RT, which returned to baseline levels after RT. Nasal cytology showed a radiation-induced rhinitis with neutrophils and sometimes bacteria. Mucous and squamous cell metaplasia appeared in 10% of patients. D_mean and D_2% to inferior turbinates were associated to neutrophilic rhinitis at T2, and D_2% to inferior turbinates was correlated to mucous cell metaplasia at T2.

CONCLUSIONS

RT for HNC induces acute rhinitis that may persist after the completion of treatment and can affect patient's quality of life. Nasal cytology can help to choose the best treatment on an individual basis.

Olfactory and gustatory functions after free flap reconstruction and radiotherapy for oral and pharyngeal cancer: a prospective follow-up study

BACKGROUND

The senses of smell and taste can be adversely affected by both tumour- and treatment-related factors amongst head and neck cancer patients. The consequences may negatively impact nutritional status as well as quality of life in this patient population.

PATIENTS AND METHODS

This prospective longitudinal follow-up study is consisted of 44 patients treated for oral cavity, oropharyngeal or hypopharyngeal cancer with tumour resection and microvascular free tissue transfer reconstruction at the Helsinki University Hospital, Helsinki, Finland. Thirty-nine (89%) of them also received radiotherapy. The senses of smell (odour detection, identification and threshold test) and taste (electrogustometry) and quality of life (UW-QOL) were evaluated preoperatively, and at 6 weeks, 3 months, 6 months and 12 months, postoperatively.

RESULTS

There were higher scores in the odour detection values in the 6-week and 3-month tests compared with preoperative values for the tumour side. Other detection scores did not differ statistically from the preoperative values neither in the tumour nor the contralateral side. However, in the odour identification test, all posttreatment values were statistically significantly higher than pretreatment ones. In the olfactory threshold test, no statistically significant differences were found between pre- and posttreatment values. Electrogustometry values for the taste on the tumour side were statistically significantly impaired at 6 weeks (p < 0.05) and at 3 months (p < 0.01) compared with the pretreatment results. They were also impaired at 6 months and at 12 months, although the differences were not statistically significant. The quality of life was impaired after treatment in this patient series. However, the correlation between quality of life and sense of taste was found only at one time point (3 months) and only with contralateral side measurements.

CONCLUSIONS

We conclude that in oral and pharyngeal cancer patients the postoperative taste problems are related to the impairment on the taste sensation in the tongue but not with the sense of smell. Moreover, the impairment in the quality of life is not clearly related to the impaired sense of taste.

Common oral complications of head and neck cancer radiation therapy: mucositis, infections, saliva change, fibrosis, sensory dysfunctions, dental caries, periodontal disease, and osteoradionecrosis

Patients undergoing radiation therapy for the head and neck are susceptible to a significant and often abrupt deterioration in their oral health. The oral morbidities of radiation therapy include but are not limited to an increased susceptibility to dental caries and periodontal disease. They also include profound and often permanent functional and sensory changes involving the oral soft tissue. These changes range from oral mucositis experienced during and soon after treatment, mucosal opportunistic infections, neurosensory disorders, and tissue fibrosis. Many of the oral soft tissue changes following radiation therapy are difficult challenges to the patients and their caregivers and require life-long strategies to alleviate their deleterious effect on basic life functions and on the quality of life. We discuss the presentation, prognosis, and management strategies of the dental structure and oral soft tissue morbidities resulting from the administration of therapeutic radiation in head and neck patient. A case for a collaborative and integrated multidisciplinary approach to the management of these patients is made, with specific recommendation to include knowledgeable and experienced oral health care professionals in the treatment team.

A systematic review of smell alterations after radiotherapy for head and neck cancer

PURPOSE

To review the current knowledge on radiotherapy associated olfactory dysfunction among head and neck cancer (HNC) patients.

METHODS

A systematic review of RT-related olfactory dysfunction in HNC was performed. Searches were conducted in several databases (Medline, EMBASE, CINAHL, CAB Abstracts, SCOPUS, Proquest Dissertations and Theses, PROSPERO, ALLEBM Reviews - Cochrane DSR, ACP Journal Club, DARE, CCTR, CMR, HTA, and NHSEED). Publications investigating olfactory dysfunction as an explicit side effect of Radiotherapy (RT, or RT-chemo or RT-monoclonal antibodies) were eligible, no limits were applied.

RESULTS

Two hundred and twenty-nine papers were screened and 23 met inclusion criteria.

CONCLUSIONS

Odor detection, identification and discrimination are olfactory functions impaired after RT for HNC. An RT dose-effect has been calculated for odor identification and odor discrimination. There were no studies of the effect of olfactory dysfunction on weight loss or energy intake among RT-treated HNC patients. To improve our understanding of RT associated olfactory dysfunction among HNC patients, future studies should include a multi-dimensional assessment of olfactory function in a longitudinal design, track other conditions affecting olfaction, assess retronasal olfactory perception, adopt validated self-report tools and explore the impact of olfactory dysfunction on the eating experience of HNC patients.

Olfactory event-related potentials: a new approach for the evaluation of olfaction in nasopharyngeal carcinoma patients treated with chemo-radiotherapy

Objective:

Olfactory dysfunction is a possible side effect of chemo-radiotherapy performed in patients affected by nasopharyngeal carcinoma. Self-rating measurements and olfactory event-related potentials were used and compared in order to evaluate the impact of this treatment on the olfactory system.

Methods:

Nine patients underwent subjective evaluation of olfactory function (using visual analogue scales for olfactory symptoms and quality of life, and a six-item Hyposmia Rating Scale), and a quantitative and objective measurement (olfactory event-related potentials).

Results:

Spearman's rank correlation analyses highlighted significant relationships between the clinical scales and olfactory event-related potentials. Inter-group analyses showed significant differences in the latency and in the amplitude of olfactory event-related potentials between patients and controls.

Conclusion:

Taking into account the small sample size and the lack of pre-treatment assessment, olfactory event-related potentials seemed to allow a more objective diagnosis of unilateral and bilateral olfactory loss. Moreover, olfactory event-related potentials and subjective scales results were concordant.

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.

[Radiation-induced neuropathies: collateral damage of improved cancer prognosis]

INTRODUCTION

Because of the improvement of cancer prognosis, long-term damages of treatments become a medical and public health problem. Among the iatrogenic complications, neurological impairment is crucial to consider since motor disability and pain have a considerable impact on quality of life of long cancer survivors. However, radiation-induced neuropathies have not been the focus of great attention. The objective of this paper is to provide an updated review about the radiation-induced lesions of the peripheral nerve system.

STATE OF THE ART

Radiation-induced neuropathies are characterized by their heterogeneity in both symptoms and disease course. Signs and symptoms depend on the affected structures of the peripheral nerve system (nerve roots, nerve plexus or nerve trunks). Early-onset complications are often transient and late complications are usually progressive and associated with a poor prognosis. The most frequent and well known is delayed radiation-induced brachial plexopathy, which may follow breast cancer irradiation. Radiation-induced lumbosacral radiculoplexopathy is characterized by pure or predominant lower motor neuron signs. They can be misdiagnosed, confused with amyotrophic lateral sclerosis (ALS) or with leptomeningeal metastases since nodular MRI enhancement of the nerve roots of the cauda equina and increased cerebrospinal fluid protein content can be observed. In the absence of specific markers of the link with radiotherapy, the diagnosis of post-radiation neuropathy may be difficult. Recently, a posteriori conformal radiotherapy with 3D dosimetric reconstitution has been developed to link a precise anatomical site to unexpected excess irradiation.

PERSPECTIVES AND CONCLUSION

The importance of early diagnosis of radiation-induced neuropathies is underscored by the emergence of new disease-modifying treatments. Although the pathophysiology is not fully understood, it is already possible to target radiation-induced fibrosis but also associated factors such as ischemia, oxidative stress and inflammation. A phase III trial evaluating the association of pentoxifylline, tocopherol and clodronate (PENTOCLO, NCT01291433) in radiation-induced neuropathies is now recruiting.

Influence of connective tissue diseases on the expression of radiation side effects: a systematic review

BACKGROUND AND PURPOSE

Patient related co-factors may increase the risk of radiation morbidity. Connective tissue diseases (CTD) are among the co-morbidities that are relatively well studied and have been shown to be of potential clinical relevance for radiotherapy. The aim of this systematic review is to quantify the contribution of CTD to the risk of radiation related side effects.

PATIENTS AND METHODS

Relevant publications reporting the outcome of radiotherapy in patients with CTD were retrieved according to a standardized query and evaluated for their methodology and quality of reporting, using defined quality criteria. A quantitative estimate of the relative risk of developing side effects in patients with CTD was derived from the observed proportions of responders in patients with or without CTD. Risk estimates were synthesized across studies.

RESULTS

Eight studies which include data of 9-209 patients who had CTD and were treated with radiotherapy were identified and reviewed. Three of these studies included data suited for further quantitative analysis. The test of the uni-directional hypothesis that patients with CTD had an increased risk of late effects after radiotherapy reached statistical significance, the one-tailed P-value being 0.03. The pooled relative risk was 2.0 with 95% confidence interval (0.99, 4.1).

CONCLUSIONS

CTD is associated with an increased risk of late radiation induced normal tissue reaction. The literature published to date provides some support for this assertion although most of the reports are plagued by methodological weaknesses, thus calling for a large coordinated study.