Application of circulating tumor DNA liquid biopsy in nasopharyngeal carcinoma: A case report and review of literature

Abstract

BACKGROUND

Circulating tumor DNA (ctDNA)-based liquid biopsy has been found to be effective for the detection of minimal residual disease and the evaluation of prognostic risk in various solid tumors, with good sensitivity and specificity for identifying patients at high risk of recurrence. However, use of its results as a biomarker for guiding the treatment and predicting the prognosis of nasopharyngeal carcinoma (NPC) has not been reported.

CASE SUMMARY

In this case study of a patient with stage IVb NPC, we utilized ctDNA as an independent biomarker to guide treatment. Chemotherapy was administered in the early stages of the disease, and local intensity-modulated radiation therapy was added when the patient tested positive for ctDNA, while radiation therapy was stopped and the patient was observed when the ctDNA test was negative. During the follow-up period, ctDNA signals became positive before tumor progression and became negative again at the end of treatment. We also explored the potential of ctDNA in combination with Epstein–Barr virus (EBV) DNA status to predict the prognosis of NPC patients, as well as the criteria for selecting genetic mutations and the testing cycle for ctDNA analysis.

CONCLUSION

The results of ctDNA-based liquid biopsy can serve as an independent biomarker, either independently or in conjunction with EBV DNA status, to guide the treatment and predict the prognosis of NPC.

Keywords: Nasopharyngeal cancer; Radiation therapy; Circulating tumor DNA; Epstein–Barr virus; Minor residual disease; Guide treatment; Predicting prognosis; Case report

Core Tip: The results of circulating tumor DNA (ctDNA)-based minimal residual disease testing have been used as a biomarker for some solid tumors, but their use as a biomarker to guide the treatment and predict the prognosis of nasopharyngeal carcinoma (NPC) has not yet been reported. We report a patient who tested positive for ctDNA and negative for Epstein‒Barr virus DNA. During the follow-up period, ctDNA signals became positive before tumor progression and became negative again at the end of treatment. This study represents a breakthrough in the use of biomarkers to assess the prognosis of NPC.