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

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