Role of salivary proteins on radiation-related caries onset in head and neck cancer patients treated with radiotherapy - a longitudinal study.

Objective: Longitudinal assessment of the role of specific proteins on radiotherapy caries (RC) onset in head and neck cancer patients (HNC)up to one-year post intensity-modulated radiation therapy (IMRT). Methods: Dental status/salivary protein data were obtained from 40 HNC patients pre-IMRT (T0), six months (T1) and 12 months (T2) post-IMRT (ethical approval/consent). DMFT and salivary parameters were quantified including flow rate, mucin 5B and 7, Immunoglobulin A (IgA), and cystatin S and α-amylase. Results: 45% patients had at least one carious lesion at T2, having a significant reduction in the number of remaining teeth (65% <21), salivary flow rate (<50%,) and, protein secretion (<0.05) post-IMRT. At T1 IgA concentration/secretion rate were associated with caries lesions (p<0.05). Finally, IgA and total protein concentration obtained at T1 could provide a predictive pattern (AUC 82.3%) for the patients more predisposed to developing RC at T2. Conclusion: This study demonstrated the significant association of RC with salivary proteins in HNC patients treated with IMRT, revealing the potential role of salivary proteins in the early diagnosis of RC. Clinical relevance: This research contributes to reveal salivary proteins association with RC, and its role in early diagnosis. Therefore, this could be the first step towards for personalized medicine approaches to improve this group quality of life (QoL).