Study of DNA Mutations in Predicting the Effect of External-Beam Radiation Therapy in Patients With Early Breast Cancer, Localized Prostate Cancer, or Gynecological Cancer

DISEASE CHARACTERISTICS: * Patients must have received curative external-beam radiotherapy within the context of a formal clinical study for any of the following: * Early breast cancer after breast-conserving surgery * Localized prostate cancer * Gynecological cancer (may have also received brachytherapy) * Venous blood samples must be available * Patients will be identified from the following clinical studies: * Cambridge intensity-modulated radiotherapy breast randomized trial * RT01 prostate radiotherapy randomized trial/other prostate trials * Christie hospital breast, prostate, and gynecological cancer radiotherapy patients * Must have minimum follow up with late normal tissue effect scoring for two years available PATIENT CHARACTERISTICS: * No other malignancy prior to treatment for the specified tumor types except basal cell or squamous cell carcinoma of the skin or in situ carcinoma PRIOR CONCURRENT THERAPY: * See Disease Characteristics