Detecting Chemosensitivity and Predicting Treatmemt Efficacy With CTCs in mNPC

This study is investigating whether measuring circulating tumor cells (cancer cells that have broken off and entered the bloodstream) can predict how well chemotherapy will work in patients with nasopharyngeal carcinoma (a cancer at the back of the nose and throat) that has spread to other parts of the body. **You may be eligible if...** - You have nasopharyngeal carcinoma that has spread to distant organs, at least 3 months after completing radiation therapy - You are not a candidate for local treatment - You are between 18 and 70 years old - You are in good general health (ECOG score 0–1) - You have at least one measurable area of disease on imaging - Your expected survival is at least 3 months **You may NOT be eligible if...** - You have another active malignancy - You are currently enrolled in another clinical trial - You have drug or alcohol dependency issues - Your blood counts or organ function are significantly abnormal Talk to your doctor to see if this trial is right for you.