A new joint ASCO guideline offers clinicians updated evidence-based recommendations for the prevention and treatment of salivary gland hypofunction and xerostomia caused by nonsurgical cancer therapies.1
The guidance was developed together by ASCO and the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO). According to the Expert Panel members, the guideline includes recommendations based on “state-of-the-art science” and has been specifically directed to prevent and/or treat the objective signs of salivary hypofunction caused by nonsurgical cancer treatments, including increased oral mucosal, dental, and periodontal infections, as well as mucosal trauma.
Additionally, the guideline includes recommendations clinicians can incorporate into clinical practice to prevent or treat subjective symptoms of xerostomia, or oral dryness. Common symptoms of this disorder include compromised ability to speak, chew food, swallow, and taste. “As such, it is hoped this guideline will provide clinicians with contemporary, well-evidenced knowledge that could in turn mitigate both the signs and symptoms of salivary dysfunction secondary to cancer therapy,” said Douglas E. Peterson, DMD, PhD, FDS RCSEd, of UConn Health, and Guideline Co-Chair.
Douglas E. Peterson, DMD, PhD, FDS RCSEd
Valeria Mercadante, PhD
Valeria Mercadante, PhD, of University College London, who also served as Guideline Co-Chair, added that the new recommendations ultimately offer an opportunity for any clinician involved in nonsurgical cancer therapies to optimize symptom management and improve the quality of life of their patients. “Rather than dictating a one-size-fits-all approach to patient care, we offered an evaluation of the quality of the relevant scientific literature to enable health-care clinicians to select the best care for a unique patient based on their preferences,” she said.
In addition to the use of parotid-sparing, intensity-modulated radiation therapy, the guideline also recommends the use of other radiation modalities that can limit the cumulative treatment dose to the major and minor salivary glands as a means of reducing salivary gland hypofunction and xerostomia risk.
To reduce the risk of developing xerostomia in patients with head and neck cancer, the guideline also recommends acupuncture and systemic administration of the sialagogue bethanechol during radiation therapy. Oral pilocarpine and cevimeline, as well as transcutaneous electrostimulation, are also recommended for patients with established xerostomia and salivary gland hypofunction.
In addition, the guideline recommends the use of gustatory and masticatory salivary reflex stimulation through sugar-free lozenges, acidic (nonerosive and sugar-free) candies, or sugar-free and nonacidic chewing gum to increase the rate of saliva flow and provide relief from xerostomia. This can be accomplished, the Guideline Co-Chairs said, by stimulating the salivary gland tissue’s residual capacity.
The guideline co-chairs also emphasized the risks associated with osteoradionecrosis in patients who develop salivary gland hypofunction, particularly risks related to dental, periradicular, and/or periodontal disease. “It is important to note that in some patients, the signs and symptoms can be permanent for the rest of the patient’s life post head and neck radiation,” Dr. Peterson said. “Thus, interventions directed to preventing and/or reducing severity of the condition can be highly impactful for the patient over time.”
Dr. Peterson believes the incorporation of the recommendations cited in the guideline into the nonsurgical management of the patient’s disease, when clinically indicated, could lead to substantial short- and long-term benefit to patients. “These benefits include reduced risk of oral infection and osteoradionecrosis, as well as enhanced quality of life over the lifetime of the patient following their cancer treatment,” he said.
Emphasizing the Importance of Patient Education
Althoughthe guideline is mostly aimed toward clinicians, the Co-Chairs added that patient education is another important facet of prevention and disease management. “Patients should also be informed of the essential protective role of saliva against tooth decay and sensitivity and should be educated about the potential impact of nonsurgical treatment on salivary gland function,” Dr. -Mercadante said. Patients with head and neck cancer undergoing radiation therapy are a particularly vulnerable group, she added, as these patients tend to experience xerostomia and hyposalivation during the first weeks of radiation therapy.
“Xerostomia and salivary gland hypofunction have a profound acute and long-term impact on a wide range of health outcomes, and therefore supportive and preventive oral health measures should be promoted to reduce the risk of side effects from oncologic treatment,” Dr. Mercadante said. Although there is currently no curative approach, she noted, “the clinician should be confident in discussing with the patient fluoride prescription in dentate individuals and topical management that may ameliorate xerostomia and its related complaints, with referral to appropriate ancillary services when indicated.”
1. Mercadante V, Jensen SB, Smith DK, et al: Salivary gland hypofunction and/or xerostomia induced by non-surgical cancer therapies: ISOO/MASCC/ASCO Guideline. J Clin Oncol. July 20, 2021 (early release online).
Originally published in ASCO Daily News. © American Society of Clinical Oncology. ASCO Daily News, July 21, 2021. All rights reserved.