Can an itchy throat that causes throat clearing and occasional cough be a sign of lung cancer?

Sure but not exactly: Especially in the cold and flu season, everybody has occasional itchy throat, scratchy throat, sore throat, throat clearing, or occasional cough. Thus, people with lung cancer have such symptoms just like the billions of other people without lung cancer. Since lung cancer is somewhat rare, one cannot say that all of us have the signs of lung cancer. It's a sign but a useless sign of cancer.