Erlotinib Completed Phase 2 Trials for Stage III Squamous Cell Carcinoma of the Oropharynx / Stage III Squamous Cell Carcinoma of the Nasopharynx / Stage IV Squamous Cell Carcinoma of the Lip and Oral Cavity / Stage III Squamous Cell Carcinoma of the Larynx / Stage III Squamous Cell Carcinoma of the Lip and Oral Cavity / Stage IV Squamous Cell Carcinoma of the Nasopharynx / Stage III Squamous Cell Carcinoma of the Hypopharynx / Stage IV Squamous Cell Carcinoma of the Hypopharynx / Stage IV Squamous Cell Carcinoma of the Larynx / Stage IV Squamous Cell Carcinoma of the Oropharynx Treatment