Erlotinib Completed Phase 1 Trials for Stage III Squamous Cell Carcinoma of the Oropharynx / Stage III Squamous Cell Carcinoma of the Lip and Oral Cavity / Stage IV Squamous Cell Carcinoma of the Lip and Oral Cavity / Stage II Squamous Cell Carcinoma of the Oropharynx / Stage IV Squamous Cell Carcinoma of the Oropharynx / Stage II Squamous Cell Carcinoma of the Lip and Oral Cavity Treatment