Summary

A methylation-based blood test detected recurrence of non-viral head and neck cancer with 76.9% sensitivity and 94.6% specificity, and preceded clinical detection by a median of 131 days in 60% of cases where both occurred. Positive results were strongly associated with worse one-year survival.

Methylation-based ctDNA test detects head and neck cancer recurrence ahead of clinical examination in 50-patient study

A blood test that detects tumor-specific DNA methylation patterns in plasma can identify recurrence of non-viral head and neck squamous cell carcinoma (HNSCC) before it becomes clinically apparent and flags patients at high risk of poor survival, according to a retrospective study of 50 patients posted as a preprint on medRxiv.

The Guardant360 assay, which sequences cell-free DNA from blood to identify methylation signals associated with the patient's tumor, showed 76.9% sensitivity and 94.6% specificity for recurrence when used during post-treatment surveillance. Among patients with a positive test, one-year progression-free survival was 25%, compared with 96.4% for those with a negative result.

Contents

Study design and patient population

The study included 50 patients with non-metastatic, non-virally associated HNSCC who had completed definitive therapy and undergone at least one Guardant360 ctDNA test during follow-up between January 2024 and October 2025. Treatment consisted of chemoradiation in 54% of patients and surgery in 46%.

Most patients had advanced disease at diagnosis: 72% had AJCC stage IVA or IVB, 69% had T3 or T4 tumors, and 48% had N2 or N3 nodal involvement. The most common primary sites were the larynx (38%) and oral cavity (36%).

A ctDNA result was considered positive when the methylation signal reached 0.05% or higher. At a median follow-up of 18.0 months, 13 patients experienced disease recurrence. Twelve of those 13 had a positive ctDNA result. The assay's diagnostic performance was:

  • Sensitivity: 76.9%
  • Specificity: 94.6%
  • Positive predictive value: 83.3%
  • Negative predictive value: 92.1%
  • Area under the ROC curve: 0.858 (95% CI, 0.733–0.982)

ctDNA as an early warning signal

Among 10 patients who both recurred and had a positive ctDNA result, the blood test detected recurrence before clinical examination in six cases, by a median of 131 days. The authors note that this lead time precedes clinical detection in most cases where both occur.

Positive ctDNA was also strongly associated with survival outcomes. Patients with a positive test had a one-year progression-free survival of 25% versus 96.4% for those with a negative result, and one-year overall survival of 75% versus 100%. Both differences were statistically significant (P < .001).

In an exploratory analysis, the researchers identified mutations in the TP53, SETD2, and ROBO2 genes as more frequent among patients who recurred, though they describe this finding as preliminary.

What this means for surveillance

Current post-treatment surveillance for HNSCC relies primarily on clinical examination and imaging, both of which have known limitations in detecting early recurrence. For non-viral HNSCC — where the role of ctDNA is less established than in HPV-positive disease — the study's findings suggest that a methylation-based blood test could complement existing methods.

The authors emphasize that the study is retrospective, conducted at a single institution, and involves a relatively small cohort. Prospective validation in a larger, multi-institutional setting is needed before ctDNA can be recommended for routine surveillance. The study has not demonstrated that acting on a positive ctDNA result improves survival outcomes.

Sources