question: my son has a persistent sore throat for a month now. saw a doctor and they thought it was sinusitis, treated him with Zithromax for 5 days and now it is back. He had swollen lymph nodes in neck when seen 2 weeks ago. says throat is still sore. He is 20 years old and just quit smoking 2 weeks ago. He smoked about 3 years. He's worried about cancer.