Sparing the region of the salivary gland containing stem cells preserves saliva production after radiotherapy for head and neck cancer
Menée à l'aide de modèles murins et sur 74 patients atteints d'un cancer de la tête et du cou, cette étude montre qu'épargner, durant une radiothérapie, la région de la glande salivaire comportant les cellules souches progénitrices permet de préserver la fonction de la glande
Radiotherapy for head and neck cancer may damage the salivary glands, resulting in reduced salivation with consequent xerostomia (dry mouth). Xerostomia affects the quality of life of patients with head and neck cancer. van Luijk and co-workers reported the location of salivary (parotid) gland stem cells in the mouse, rat, and human. Next, they showed in rat and human that irradiation of the salivary gland region containing the highest number of stem cells resulted in the greatest loss of saliva production after treatment. Finally, the authors showed that it is possible to avoid irradiation of this specific area during therapy, which may reduce the patient’s risk of developing post-radiotherapy xerostomia.Each year, 500,000 patients are treated with radiotherapy for head and neck cancer, resulting in relatively high survival rates. However, in 40% of patients, quality of life is severely compromised because of radiation-induced impairment of salivary gland function and consequent xerostomia (dry mouth). New radiation treatment technologies enable sparing of parts of the salivary glands. We have determined the parts of the major salivary gland, the parotid gland, that need to be spared to ensure that the gland continues to produce saliva after irradiation treatment. In mice, rats, and humans, we showed that stem and progenitor cells reside in the region of the parotid gland containing the major ducts. We demonstrated in rats that inclusion of the ducts in the radiation field led to loss of regenerative capacity, resulting in long-term gland dysfunction with reduced saliva production. Then we showed in a cohort of patients with head and neck cancer that the radiation dose to the region of the salivary gland containing the stem/progenitor cells predicted the function of the salivary glands one year after radiotherapy. Finally, we showed that this region of the salivary gland could be spared during radiotherapy, thus reducing the risk of post-radiotherapy xerostomia.