Review question
To establish the evidence for the effects of therapeutic swallowing exercises, undertaken before, during and/or immediately after head and neck cancer treatment, on swallowing.
Background
A swallowing impairment (dysphagia) commonly occurs as a result of head and neck cancer treatment. It may be temporary, resulting from a dry mouth or irritation of the lining of the mouth during treatment, or permanent due to a narrowing (stricture) of the throat after surgery and/or radiotherapy. Undertaking swallowing exercises before, during and/or immediately after HNC treatment may prevent dysphagia occurring, or may reduce its severity.
Clinicians who are treating dysphagia in head and neck cancer patients lack evidence-based guidelines so it is challenging to determine which interventions are suitable, but many speech and language therapists encourage patients to undertake exercises intensively throughout head and neck cancer treatment, based on a 'use it or lose it' principle.
Study characteristics
We included six studies with 326 participants who undertook therapeutic exercises before, during and/or after HNC treatment. We could not combine the results of the studies because of the variation in participants' cancers, their treatments, the outcomes measured and the tools used to assess them, as well as the differing time points for testing. Researchers have compared: (i) therapeutic exercises versus treatment as usual (TAU); (ii) therapeutic exercises versus sham therapy; (iii) therapeutic exercises plus TAU versus TAU. The therapeutic exercises varied in their design, timing and intensity. TAU involved managing patients' dysphagia when it occurred, including inserting a tube for non-oral feeding.
Key results
The evidence is up to date to 1 July 2016.
We found no evidence that therapeutic exercises were better than TAU, or any other treatment, in improving the safety and efficiency of oral swallowing (our primary outcome) or in improving any of the secondary outcomes. However, there is insufficient evidence to draw any clear conclusion about the effects of undertaking therapeutic exercises before during and/or immediately after HNC treatment on preventing or reducing dysphagia. Studies had small participant numbers, used complex interventions and varied in the choice of outcomes measured, making it difficult to draw reliable conclusions. There were no reported adverse events directly attributable to the intervention (swallowing exercises).
Quality of evidence
The current quality of the evidence to support the use of therapeutic exercises before, during and/or immediately after HNC treatment to prevent/reduce dysphagia is very low. We need better designed, rigorous studies with larger participant numbers and agreed endpoints and outcome measurements in order to draw clear(er) conclusions.
We found no evidence that undertaking therapeutic exercises before, during and/or immediately after HNC treatment leads to improvement in oral swallowing. This absence of evidence may be due to the small participant numbers in trials, resulting in insufficient power to detect any difference. Data from the identified trials could not be combined due to differences in the choice of primary outcomes and in the measurement tools used to assess them, and the differing baseline and endpoints across studies.
Designing and implementing studies with stronger methodological rigour is essential. There needs to be agreement about the key primary outcomes, the choice of validated assessment tools to measure them and the time points at which those measurements are made.
Head and neck cancer treatment has developed over the last decade, with improved mortality and survival rates, but the treatments often result in dysphagia (a difficulty in swallowing) as a side effect. This may be acute, resolving after treatment, or remain as a long-term negative sequela of head and neck cancer (HNC) treatment. Interventions to counteract the problems associated with dysphagia include swallowing exercises or modification of diet (bolus texture, size), or both.
To determine the effects of therapeutic exercises, undertaken before, during and/or immediately after HNC treatment, on swallowing, aspiration and adverse events such as chest infections, aspiration pneumonia and profound weight loss, in people treated curatively for advanced-stage (stage III, stage IV) squamous cell carcinoma of the head and neck.
The Cochrane ENT Information Specialist searched the ENT Trials Register; Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 6); MEDLINE; PubMed; Embase; CINAHL; LILACS; KoreaMed; IndMed; PakMediNet; Web of Science; ClinicalTrials.gov; ICTRP; speechBITE; Google Scholar; Google and additional sources for published and unpublished trials. The date of the search was 1 July 2016.
We selected randomised controlled trials (RCTs) of adults with head and neck cancer (stage III, stage IV) who underwent therapeutic exercises for swallowing before, during and/or immediately after HNC treatment to help produce safe and efficient swallowing. The main comparison was therapeutic exercises versus treatment as usual (TAU). Other possible comparison pairs included: therapeutic exercises versus sham exercises and therapeutic exercises plus TAU versus TAU. TAU consisted of reactive management of a patient's dysphagia, when this occurred. When severe, this included insertion of either a percutaneous endoscopic gastroscopy or nasogastric tube for non-oral feeding.
We used the standard methodological procedures expected by Cochrane. Our primary outcomes were: safety and efficiency of oral swallowing, as measured by reduced/no aspiration; oropharyngeal swallowing efficiency (OPSE) measures, taken from videofluoroscopy swallowing studies; and adverse events, such as chest infections, aspiration pneumonia and profound weight loss. Secondary outcomes were time to return to function (swallowing); self-reported changes to quality of life; changes to psychological well-being - depression, anxiety and stress; patient satisfaction with the intervention; patient compliance with the intervention; and cost-effectiveness of the intervention.
We included six studies (reported as seven papers) involving 326 participants whose ages ranged from 39 to 83 years, with a gender bias towards men (73% to 95% across studies), reflecting the characteristics of patients with HNC. The risk of bias in the studies was generally high.
We did not pool data from studies because of significant differences in the interventions and outcomes evaluated. We found a lack of standardisation and consistency in the outcomes measured and the endpoints at which they were evaluated.
We found no evidence that therapeutic exercises were better than TAU, or any other treatment, in improving the safety and efficiency of oral swallowing (our primary outcome) or in improving any of the secondary outcomes.
Using the GRADE system, we classified the overall quality of the evidence for each outcome as very low, due to the limited number of trials and their low quality. There were no adverse events reported that were directly attributable to the intervention (swallowing exercises).