Objective: Symptoms and clinical signs of decreased saliva secretion are a common after cancer therapy. The goal of this research is to systematically review the evidence about the efficacy of photobiomodulation therapy (PBMT) for the management of cancer treatment-related xerostomia or salivary hypofunction. Methods: PubMed was searched for articles investigating the clinical effects of PBMT on cancer therapy-related xerostomia or hyposalivation. The publications that met the eligibility criteria were evaluated for the quality of the study design, physical parameter setting reproducibility, specifics of the treatment protocol, clinical outcomes, and adverse effects. The strongest evidence was given a heavier weight in the overall conclusions. Results: A total of 314 articles were identified, and 5 controlled trials were included in this systematic review. Most of the studies were in head and neck cancer patients treated with radiotherapy (RT) or radiochemotherapy (RT-CT), and one study was in dry mouth associated with hematopoietic stem cell transplantation (HSCT). Data showed conflicting results for either prevention or treatment of RT- or RT-CT-induced dry mouth or hyposalivation. The data for HSCT-related dry mouth were positive. Conclusions: Despite positive preliminary outcomes in most of the trials, it is too early to confidently determine the efficacy of PBM for cancer therapy-related hyposalivation or xerostomia.

The human salivary gland (SG) has an elegant architecture of epithelial acini, connecting ductal branching structures, vascular and neuronal networks that together function to produce and secrete saliva. This review focuses on the translation of cell- and tissue-based research toward therapies for patients suffering from SG hypofunction and related dry mouth syndrome (xerostomia), as a consequence of radiation therapy or systemic disease. We will broadly review the recent literature and discuss the clinical prospects of stem/progenitor cell and tissue-based therapies for SG repair and/or regeneration. Thus far, several strategies have been proposed for the purpose of restoring SG function: (1) transplanting autologous SG-derived epithelial stem/progenitor cells; (2) exploiting non-epithelial cells and/or their bioactive lysates; and (3) tissue engineering approaches using 3D (three-dimensional) biomaterials loaded with SG cells and/or bioactive cues to mimic in vivo SGs. We predict that further scientific improvement in each of these areas will translate to effective therapies toward the repair of damaged glands and the development of miniature SG organoids for the fundamental restoration of saliva secretion. Stem Cells 2017;35:97-105.