Chemoradiotherapy combined with NK cell transfer in a patient with recurrent and metastatic nasopharyngeal carcinoma inducing long-term tumor control: A case report.

Rationale: Nasopharyngeal carcinoma (NPC) is one of the most common malignancies in Southern China. Although combined chemotherapy with radiotherapy has been widely used in treating locally advanced lesions, relapse and metastases remain the primary cause of treatment failure, and are associated with an extremely poor prognosis. Therefore, more efficient and milder therapies are needed.

Patient Concerns: Herein, we report a patient with advanced NPC with intracranial metastases who showed progression during conventional treatment.

Diagnoses: Nonkeratinizing undifferentiated nasopharyngeal carcinoma (stage IV).

Interventions: After the completion of initial chemoradiotherapy and targeted therapy, metastases to brain occurred during follow-up. Ex vivo-cultured allogeneic NK cell infusion was offered.

Outcomes: Although the intracranial metastases did not decrease 10 months after the NK cell treatment, they decreased significantly at 31 months after the treatment and partially disappeared. The tumor response indicated partial response. Furthermore, all of the intracranial metastases continued to decrease at about 42 months after treatment.

Lessons: The brain metastases of NPC are rare with poor prognosis. Radiotherapy in NPC can disrupt the blood-brain barrier, which may contribute to the metastases of brain. This case report will provide rationale for NK cell infusion following regular chemoradiotherapy.