Oral Complications of Chemotherapy and Head/Neck Radiation (PDQ®): Supportive care - Health Professional Information [NCI] - Conditions Affected By Both Chemotherapy and Head / Neck Radiation
Salivary Gland Hypofunction and Xerostomia
Radiation therapy can damage salivary glands, causing salivary hypofunction and xerostomia. (Refer to the Oral Complications of Head and Neck Radiation section for more information.) In addition, selected chemotherapeutic agents (singly or in combination) have been implicated in causing salivary dysfunction and xerostomia. However, it has not been possible to draw consistent conclusions about the effects of cancerchemotherapy on salivary gland function.
The clinical utility of the test refers to the likelihood that the test will, by prompting an intervention, result in an improved health outcome. The clinical utility of a genetic test is based on the health benefits related to the interventions offered to people with positive test results. Theoretically, there are at least five strategies that might improve the health outcome of people with a genetic susceptibility to cancer:
Correction of the underlying genetic defect (not currently available)...
Difficulties with speaking, eating and drinking, or drooling may affect mental health and put patients and family members in social isolation.
All of these problems, plus the patient perception of swallowing difficulties, significantly decrease health-related quality of life.[3,4]
Dysphagia is most prominent in patients with head and neck cancers but may also develop in patients with other malignancies as a symptom of oropharyngeal or esophageal mucositis or infection. In addition, dysphagia can be associated with graft-versus-host disease.
The prevalence and severity of pretreatment dysphagia associated with head and neck tumors depend on tumor stage and localization. Pretreatment dysphagia is most prevalent in patients with pharyngeal and laryngeal cancers. Surgical interventions for head and neck tumors result in anatomic or neurologic insults with site-specific patterns of dysphagia. In general, the larger the resection, the more swallowing function will be impaired.
The severity of radiation-induced dysphagia depends on the following:
Total radiation dose.
Fraction size and schedule.
Treatment delivery techniques.
Feeding status (via percutaneous endoscopic gastrostomy [PEG] tube or nil per os [NPO, nothing by mouth]).
Intensified schedules and the use of chemoradiation therapy have been shown to improve locoregional control and survival but come at the cost of more severe acute and chronic side effects. Intensity-modulated radiation therapy (IMRT) has emerged as an effective technique to deliver the full radiation dose to the tumor and regions at risk while reducing exposure of surrounding healthy tissues. However, the preservation of anatomy does not necessarily translate into the preservation of swallowing function.
Mucositis induced by chemoradiation therapy or chemotherapy alone, edema, pain, thickened mucous saliva and hyposalivation, radiation dermatitis, and infection may all contribute to acute dysphagia. The use of epidermal growth factor inhibitors seems not to be associated with increased mucositis and acute dysphagia.