Tumor-Specific Methylation in Saliva: A Promising Biomarker for Early Detection of Head and Neck Cancer Recurrence

Abstract

Purpose: Our goal was to define tumor and saliva gene methylation profile of head and neck squamous cell carcinoma and to evaluate its prognostic significance and its biomarker potential for early detection of relapse. Experimental Design: We prospectively analyzed 11 genes by methylation-specific PCR on primary tumors, histologically normal adjacent mucosa, and saliva from 90 French patients at diagnosis and during follow-up as well as on 30 saliva specimens from control-matched patients with nonmalignant head and neck pathology. Five additional genes were analyzed on 50 tumors of the series. Results: Methylation ofTIMP3, ECAD, p16, MGMT, DAPK, and RASSF1was the most frequently observed in tumors and paired saliva samples were analyzed at diagnosis, with an excellent agreement between both samples. At least one of these six genes was methylated in >75% of the samples without additional positive samples when other genes were analyzed. Methylation profile was similar in newly diagnosed and second primary cancers. Aberrant methylation was not associated with a worse prognosis. Ninety percent of normal adjacent mucosa and all control saliva samples were negative.Twenty-two patients were followed after treatment; abnormal methylation was detectable in the saliva of five patients few months before clinical and 2-deoxy-2[ 18 F]fluoro-D-glucose-positron emission tomography signs of relapse, allowing curable surgery. Saliva samples were negative for the17 other patients: 16 were in remission and only1relapsed. Conclusions: Gene methylation in saliva is a promising biomarker for the follow-up and early detection of still curable relapses of head and neck squamous cell carcinoma patients.

Hypermethylation, risk factors, clinical characteristics, and survival in 235 patients with laryngeal and hypopharyngeal cancers

“…In our cohort of patients with laryngeal and hypopharyngeal cancer, we did not observe any correlation between mortality and hypermethylation of any of the 4 investigated genes, either alone or in combination. Similarly, some previous investigators did not observe any effect of either p16 hypermethylation or MGMT hypermethylation on the prognosis for patients with head and neck cancer 29,30 and esophageal cancer 11 ; whereas the results from other studies 5,8 suggested a role of MGMT hypermethylation in the survival of patients with head and neck cancer. An association between aberrant gene methylation and the development of SPTs has been suggested.…”

Aberrant DNA methylation of tumor‐related genes in oral rinse

“…Detection of aberrant methylation of ECAD, MGMT, DAPK, RARb, FHIT, p16, p15, TIMP3, and APC in saliva samples from patients with oral cancer 14 and of HIN-1 and WIF-1 in oral cancer tissue samples has been reported previously. 22,23 Although the aberrant methylation of TMEFF2 and SPARC has been reported …”

“…[10][11][12][13] Therefore, the determination of DNA methylation status may represent a target for identifying OSCC, and the creation of methylation gene panels could be useful for OSCC screening to assist in its early detection, monitoring, and treatment. 12,13 Several studies to date have attempted to detect OSCC using aberrant DNA methylation in samples obtained from oral rinses or saliva 14,15 ; however, the reported sensitivities and specificities of the methods for cancer detection have not been sufficient to justify their use as screening tests for OSCC.…”

The context and potential of epigenetics in oncology

“…Serial analysis of serum or biofluid DNA methylation patterns may one day enable the detection of early relapse before it manifests with clinical symptoms or on routine imaging, affording an extended window in which cure may still be achievable. One small prospective study has already shown that gene methylation (panel of 10 genes) in saliva is a promising biomarker for the follow-up and early detection of still curable relapses of head and neck squamous cell carcinoma patients (Righini et al, 2007).…”