Hi,
The chances that this is cancer are very less. The most important thing here is - you need to stop smoking
immediately. This could be due to bacterial infection - tonsillitis, pharyngitis etc. Oral thrush or candida
infection, sinusitis causing a post nasal drip, gastro-esophageal reflux causing acid to irritate the back of
the throat are some other causes. Stress can also cause similar symptoms. It would help to try warm saline
gargles, steam inhalation , avoidance of chilled liquids, alcohol and smoking when you have this. An ENT
consultation would help in finding out the exact cause. Regards.