Lapatinib Completed Phase 2 Trials for Stage IV Squamous Cell Carcinoma of the Lip and Oral Cavity / Recurrent Squamous Cell Carcinoma of the Larynx / Metastatic Squamous Neck Cancer With Occult Primary / Recurrent Squamous Cell Carcinoma of the Hypopharynx / Recurrent Metastatic Squamous Neck Cancer With Occult Primary / Recurrent Squamous Cell Carcinoma of the Nasopharynx / Stage IV Squamous Cell Carcinoma of the Nasopharynx / Untreated Metastatic Squamous Neck Cancer With Occult Primary / Stage IV Squamous Cell Carcinoma of the Hypopharynx / Stage IV Squamous Cell Carcinoma of the Larynx / Stage IV Squamous Cell Carcinoma of the Oropharynx / Stage IV Squamous Cell Carcinoma of the Paranasal Sinus and Nasal Cavity / Recurrent Squamous Cell Carcinoma of the Paranasal Sinus and Nasal Cavity / Recurrent Squamous Cell Carcinoma of the Oropharynx / Salivary Gland Squamous Cell Carcinoma / Recurrent Squamous Cell Carcinoma of the Lip and Oral Cavity Treatment