What are most commonprecursor lesions?

Squamous metaplasia and dysplasia of bronchial mucosa (habitual smokers at risk for lung carcinoma) Endometrial hyperplasia and dysplasia (women unopposed to estrogen stimulation, risk for endometrial carcinoma) Leukoplakia of oral cavity/vulva/ penis could become squamous cell carcinoma Note that Villous adenoma of colon is a precursor and precancerous condition