Collecting Tissue Samples From Patients With Cancer Undergoing Radiation Therapy and Healthy Participants

DISEASE CHARACTERISTICS: * Pathologically-proven diagnosis of malignancy * Planning treatment with radiation therapy PATIENT CHARACTERISTICS: * Able to perform follow-up visits * Is a patient of the University of Texas Southwestern Medical Center physicians PRIOR CONCURRENT THERAPY: * See Disease Characteristics * Participation in other clinical trials is allowed * Other prior or concurrent therapy for cancer, such as surgery and/or chemotherapy, is allowed. Criteria for eligibility: * Able to provide written informed consent * Age greater than 18 years old * Males and Females are eligible * Any ethnicity is eligible Criteria for ineligibility: -Patients not available for follow-up/future contact