Chemotherapy in Combination With Methionine Restriction Induced A Complete Response in a Patient With Recurrent Metastatic Tongue Squamous-Cell Carcinoma.

Background/Aim: Recurrent head and neck squamous-cell carcinoma (HNSCC) is associated with poor prognosis and limited treatment options, particularly after failure of standard therapies including surgery, radiotherapy, chemotherapy, and immune checkpoint inhibitors. Methionine restriction has emerged as a novel clinical metabolic therapeutic strategy targeting the methionine addiction of cancer cells. The present patient report describes a case of recurrent tongue HNSCC that achieved complete remission with chemotherapy combined with methionine restriction. Case Report: F]fluorodeoxyglucose positron-emission tomography (PET)/computed tomography (CT) performed according to standard clinical protocols. Rapid tumor regression was observed. Follow-up magnetic resonance imaging (MRI) and PET/CT demonstrated complete response, which was maintained after de-escalation to cetuximab combined with MR. Conclusion: The present case demonstrates the potential clinical efficacy of combining chemotherapy with MR in the treatment of recurrent HNSCC after curative-intent surgery and failure of standard therapies, including immune checkpoint inhibition. MR may represent a promising metabolic therapeutic approach for refractory HNSCC. Αdditional cases and prospective clinical trials are necessary.