Early Diagnosis of Oral Cancer and Lesions in Fanconi Anemia Patients: A Prospective and Longitudinal Study Using Saliva and Plasma

Abstract

Fanconi anemia; Cancer gene; Saliva

Anèmia de Fanconi; Gen del càncer; Saliva

Anemia de Fanconi; Gen del cáncer; Saliva

Fanconi anemia (FA) patients display an exacerbated risk of oral squamous cell carcinoma (OSCC) and oral potentially malignant lesions (OPMLs) at early ages. As patients have defects in their DNA repair mechanisms, standard-of-care treatments for OSCC such as radiotherapy and chemotherapy, give rise to severe toxicities. New methods for early diagnosis are urgently needed to allow for treatment in early disease stages and achieve better clinical outcomes. We conducted a prospective, longitudinal study wherein liquid biopsies from sixteen patients with no clinical diagnoses of OPML and/or OSCC were analyzed for the presence of mutations in cancer genes. The DNA from saliva and plasma were sequentially collected and deep-sequenced, and the clinical evaluation followed over a median time of approximately 2 years. In 9/16 FA patients, we detected mutations in cancer genes (mainly TP53) with minor allele frequencies (MAF) of down to 0.07%. Importantly, all patients that had mutations and clinical follow-up data after mutation detection (n = 6) developed oral precursor lesions or OSCC. The lead-time between mutation detection and tumor diagnosis ranged from 23 to 630 days. Strikingly, FA patients without mutations displayed a significantly lower risk of developing precursor lesions or OSCCs. Therefore, our diagnostic approach could help to stratify FA patients into risk groups, which would allow for closer surveillance for OSCCs or precursor lesions.

This study was funded by Instituto de Salud Carlos III (ISCIII) through the projects CB16/12/00228/CIBERONC, PI18/00263 and P121/00208; co-funded by FEDER and the European Union; and funded by a grant from the Spanish Fundacion Anemia de Fanconi. J.P. was supported by a FEDER co-funded grant (ref. PEJ2018-002040-A) from the Ministerio de Ciencia e Innovación. J.O. was supported by a FEDER co-funded grant (ref. PEJ-2019-TL_BMD-12905) from the Comunidad de Madrid. The funding sources were not involved in study design; in the collection, analysis and interpretation of data; in the writing of the report; or in the decision to submit the article for publication.