Comparison with other studies and clinical applicability
The literature on the functional failure following primary (C)RT for
advanced laryngeal cancer is scarce and oftentimes conflicting. This is
partly explained by the lack of consensus on the definition of
functional laryngeal failure. Earlier studies have focused on salvage
laryngectomy as the key outcome, however more recent studies have
emphasised the importance of accounting for all types of laryngeal
dysfunction while assessing the effects of organ preservation
therapies[5][6]. Our definition is based on those reported in
previous studies and addresses key aspects of the laryngeal functions
(airway patency, airway protection and swallow)[5]. Dysphonia was
not included in the definition as the majority of the patients had vocal
complaints. Over 30% of the subjects were found to have NFL in the
present study, underlining the importance of careful patient counselling
about the expectations of treatment. This figure is higher compared to
the study by Heukelom et al. which found 21% develop NFL following
(C)RT, which might be explained by a high proportion of non-laryngeal
cancers and early stage (T1-T2) tumours included in that study[5].
The identification of factors associated with poor laryngeal function
following CRT has been a subject of several studies, however the
findings have been far from consistent[5][6]. Smoking has been
found to be strongly associated with worse functional outcomes in
several studies, which is echoed by our results[5][7]. Likewise,
vocal cord fixation was identified to carry a significantly increased
risk of locoregional failure and while CRT is still often employed is
considered by many to be a marker of poor outcome[8][9].
Conversely, other factors including T stage, nodal status and
pre-epiglottic extension were not found to be of a useful predictive
value. This has also been shown to be of variable importance in the
published literature[10][6].