Hello, This is Dr. Viraj Shah. Public Health expert answering your query. As you have smoked weed for more than 3 years and now trying to quit, the cilia, hair-like projections in the throat that help in removing harmful substances out of the body, that were degenerated due to repeated exposure to harmful chemicals ion the smoke, are starting to regenerate in absence of harmful chemicals. These regeneration is causing irritation in the throat leading to cough. So coughing is a sign of healing after quitting smoking and it is good. In addition, what you are experiencing might be infection of the throat that can be treated by taking Azithromycin 500 mg (Azee 500) once day for three days. You can also do lukewarm salt water gargles for relief. I do not think that you need to worry about cancer for a just a week of sore throat and cough. If you start developing cough that persists even after treatments, lose weight without any plausible cause, have unexplained fever or fatigue etc., then cancer might be taken as a possibility. You will be more at risk for developing cancer than people who are not addicted to smoking. I hope this information helps you. Thank you for choosing HCM. Let me know if you have follow up questions.