Study of Effectiveness of Lovastatin to Prevent Radiation-Induced Rectal Injury

The HMG-coA reductase inhibitor used in this study will be lovastatin. Dosage: 20 mg/d PO with evening meal. Patients on a higher dose of lovastatin at the time of study entry may continue at that dose level; for patients switching to lovastatin, the dose will be at the discretion of the prescribing physician, but must be at least 20 mg/day.Schedule: begin on the first day of external beam radiation therapy (external beam alone or external beam followed by brachytherapy) or on the day of brachytherapy (brachytherapy alone or brachytherapy followed by external beam radiotherapy) and continue for 12 months. Patients or their third party payers will be expected to cover the cost of the drug.