Sargramostim in Decreasing Mucositis in Patients Receiving Radiation Therapy for Head and Neck Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed head and neck carcinoma with planned external beam radiotherapy to include 50% of oropharynx, oral cavity, or both] * Planned external beam radiotherapy of 60-70 Gy total dose to the primary tumor or standard ports for an unknown primary tumor * Neck metastases from an unknown primary allowed if radiotherapy planned to at least 50% of the salivary gland at a dose of at least 50 Gy * No T1-T2 glottic tumors * No residual oral/oropharyngeal injury from prior chemotherapy PATIENT CHARACTERISTICS: Age: * Not specified Performance status: * Karnofsky 60-100% Life expectancy: * Not specified Hematopoietic: * Not specified Hepatic: * Not specified Renal: * Not specified Other: * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No allergy or idiosyncratic response to sargramostim (GM-CSF) * HIV negative PRIOR CONCURRENT THERAPY: Biologic therapy: * Not specified Chemotherapy: * See Disease Characteristics * No concurrent chemotherapy other than cisplatin Endocrine therapy: * Not specified Radiotherapy: * See Disease Characteristics * No prior radiotherapy to the head and neck Surgery: * Not specified Other: * No concurrent enrollment on other RTOG head and neck studies * No concurrent oral care medications (e.g., amifostine, chlorhexidrine gluconate, sucralfate, or benzydamine HCl) during study radiotherapy * No concurrent selective oral cavity decontamination (e.g., IB-367) during study radiotherapy