Radiotherapy of the neck influences the distribution of laryngeal secretory glands

Abstract

To elucidate the influence of radiation therapy on the larynx in patients who receive radiotherapy to the neck, we observed the changes in the distribution of the laryngeal glands. Human adult larynges from patients with either laryngeal or hypopharyngeal cancer were histopathologically examined, and the changes in the glandular distribution as well as in the ratio of serous or mucous type cells were surveyed using an image analysis system. The mean ratio of the area occupied by glandular acini in the subglottic larynx was 0.182 in the non-radiation group and 0.098 in the radiation group (p < 0.001). Although no statistical difference was observed, the average density of the glands decreased and the average ratio of serous-type/mucous-type glandular cells decreased in the irradiated larynx. The glandular acini are often replaced with fibrous connective tissue and the ratio of serous-type glandular cells decreases. These results indicate that not only the voice function but also the local defence function of the larynx might be impaired after radiotherapy.

Effect of Irradiation on the Human Laryngeal Glands

“…Only a few studies have been carried out regarding the immunologic status of secretory glandular tissue in the larynx after radiotherapy. The average density of the laryngeal glands decreases and the average ratio of serous-type to mucous-type glandular cells decreases in the irradiated larynx 8 ; consequently, not only the voice function, but also the local defense function, of the larynx might be impaired after radiotherapy. 8 In the irradiated laryngeal glands, secretory granules in the serous cells had decreased.…”

“…Irradiation's effects on the distribution of laryngeal secretory glands have been examined by light microscopy. 8 The average density of the glands decreased and the average ratio of serous-type to mucous-type glandular cells decreased in the irradiated larynx. 8 Irradiation's effects on the laryngeal glands were examined in the present study by electron microscopy, and the effects on laryngeal functions are discussed.…”

Local immune status and tumour marker expression in the human larynx

“…In the tissue regions that have been irradiated, however, the Cyfra 21-1 distribution pattern may be affected. In our recent study of the larynx in patients receiving radiotherapy to the neck, the laryngeal glands were often found to have been replaced by fibrous connective tissue 11 . The ratio of serous-type glandular acini to mucous-type glandular acini was also decreased.…”

Extreme long‐term voice outcomes after concurrent chemoradiotherapy for advanced non‐laryngeal head and neck cancer: Eight‐year post‐treatment analysis

“…Vocal fold lubrication is crucial for normal phonation. The concentration of serous and mucinous cells within the larynx decrease following incidental irradiation, producing dryness and altering the vibratory properties of the vocal folds . Similarly, fibrosis, oedema and structural alteration of the upper aerodigestive tract may affect speech intelligibility by altering the ability to amplify sound through sympathetic resonation .…”