The Classification of Laryngeal Cancer from a Radiotherapeutic Viewpoint

Abstract

For over sixty years it has been customary to classify laryngeal cancer into two main groups: (1) Intrinsic—where cancer arises within the cavity of the larynx (true cords, false cords and ventricle, subglottic space). (2) Extrinsic—where cancer arises from the aperture and pharyngeal surface of the larynx (epiglottis, aryoepiglottic folds, arytenoids, pyriform fossæ, post cricoid region). Considering the difficulties of classification in medicine where cases rarely lend themselves to stereotyped grouping, the persistence and wide adoption of this particular one provide clear evidence of its value. Nevertheless, although this classification is of great use to the surgeon, it does not follow that it is of equal value to the radiotherapist. This is well shown by the confusion in the use of the terms “intrinsic” and “extrinsic” existing in radiotherapeutic literature, where some authors tend to consider all forms together and fail to distinguish between “intrinsic” and “extrinsic” disease, whilst others who make this distinction fail to attach to each group the significance and special consideration that it merits. From the radiotherapist's view-point this surgical classification is unsatisfactory, because included under the heading “laryngeal cancer” are various separate and distinct types of neoplasms between which the only common bond is anatomical proximity to the boundaries of the larynx.