KEY POINTS
- This prospective Swedish cohort initially included 211 patients receiving curative-intent radiotherapy for head and neck cancer, with assessments before treatment and at 12 months, 5 years and 10 years. Patients with pre-existing trismus were excluded.
- Trismus was defined objectively as a maximum interincisal opening of ≤35 mm. Prevalence was 27% at 12 months, 28% at 5 years, and increased to 35% at 10 years among survivors available for assessment.
- At 10 years, 114 of the original 211 patients (54%) remained in follow-up. Those completing the study had been younger, healthier and had fewer recurrences at baseline, meaning the final trismus prevalence may underestimate the burden in the original cohort.
- Patients with trismus consistently reported worse quality of life. At 10 years they had worse scores than patients without trismus across 12 of 15 EORTC QLQ-C30 domains/items and 12 of 14 head-and-neck-specific scales.
- Persistent problems included mouth opening, swallowing, dry mouth, sticky saliva, speech, social eating and dental symptoms. Trismus-specific questionnaire scores also remained worse across jaw problems, eating limitations, muscular tension and facial pain.
- Most late symptoms were remarkably stable once established. Between 5 and 10 years, there were few statistically significant changes, suggesting that much of the long-term functional burden had already become persistent by year 5.
- Despite this burden, only 13% of all 10-year survivors were using a jaw-training device, including 18% of patients with trismus. Interpretation is limited by substantial long-term attrition and radiotherapy fractionation schedules from 2007-2012 that differ from current practice.
CLINICAL TAKEAWAY
Trismus should be treated as a genuine long-term survivorship issue rather than a temporary post-radiotherapy toxicity. The persistence of symptoms together with low use of jaw-training devices supports greater emphasis on long-term screening, patient counselling and rehabilitation, although modern radiotherapy techniques may produce lower rates than this historical cohort.