Is Lipidomic the Answer to the Search of a Biomarker for Organ Preservation Protocol in Head and Neck Squamous Cell Carcinoma?

In the last decade organ preservation protocols based on chemoradiotherapy (CRT) has been showing the possibility of preserving function without jeopardizing survival for locally advanced head and neck squamous cell carcinoma (HNSCC). Still, only a percentage of the patients will benefit from this approach and, to date, no biomarkers are known to correctly predict these patients. More recently, modern mass spectrometry method has been used to determine metabolic profiles, and lipidomics, in particular, emerged as a new field of study in oncology and other diseases. This study aimed to analyze the lipid profile on saliva from patients undergoing to a prospective, single center, open-label, non-randomized phase II trial for organ preservation on HNSCC. The lipid analysis was performed using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS). Multivariate statistical analyses based on principal component analysis and orthogonal partial least square-discriminant analysis were applied to MALDI-TOF-MS data to visualize differences between the lipid profiles and identify potential biomarkers. The results assisted on distinguishing complete responders from non-responders to the treatment protocol. In conclusion, we demonstrated that a group of lipids is differentially abundant in saliva from HNSCC patients submitted to an organ preservation protocol, being able to differentiate responders from non-responders. These results suggest the potential use of lipid biomarkers to identify patients who may benefit from this treatment. Also, we showed that saliva testing might be routinely used in clinical practice, for being a non-invasive alternative to blood testing, besides inexpensive and easy to obtain.