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

Oral lovastatin will be given at the dose of 20 mg/day with evening meal beginning on the first day of external beam radiation therapy (external beam alone or external beam followed by brachytherapy) or on the first day of brachytherapy (brachytherapy alone or brachytherapy followed by external beam radiotherapy) and continue for 12 months.

Inclusion criteria

• Histologically or cytologically confirmed diagnosis of adenocarcinoma of the prostate
• Planned treatment with radiation therapy to include external beam and/or brachytherapy with curative intent (total dose ≥60 Gy). A portion of the rectum must receive at least 60 Gy.
• Age at least 18 years
• Karnofsky Performance Status (KPS) ≥ 70
• No history of prior radiotherapy to the prostate or rectum
• History of prior malignancy, if likely to live at least 4 years, is acceptable.
• No evidence of distant metastases
• Patients may be taking an HMG-coA-reductase inhibitor, but to be eligible, they must be able to be changed to lovastatin 20 mg/day, with the permission of their prescribing physician.
• Creatine kinase < 5 times upper normal limit
• Sufficient renal function defined as calculated creatinine clearance ≥ 30ml/min
• transaminases < 3 times upper normal limit

Exclusion criteria

• Planned abdomino-perineal resection after radiotherapy
• Contraindication to an HMG-coA-reductase inhibitor
• Major medical or psychiatric illness, which in the investigator's opinion, would prevent completion of treatment and would interfere with follow-up.
• Currently taking an inhibitor of cytochrome P450 3A4
• Active liver or muscle disease