Calcitriol in Preventing Lung Cancer in High-Risk Patients

Inclusion Criteria

• Must have pathologically confirmed squamous metaplasia or squamous dysplasia documented by autofluorescence bronchoscopy within the preceding 60 months
• Must be a former or current smoker
• Total granulocyte count of > 1.5 x 10^9/L
• Platelet count of > 100 x 10^9/L
• Participants must have adequate renal function with a calculated creatinine clearance of > 60 ml/min from a serum specimen collection at baseline using the Cockcroft-Gault formula
• Participants must have a 24-hour calcium concentration that is =< 300 mg/24 hours as measured by 24-hour urine collection at baseline
• Total bilirubin less than the upper limit of normal
• Transaminases =< 2.5 x institutional upper limit of normal (IULN)
• Alkaline phosphatase =< 2.5 x IULN
• Albumin of >= 2.5 g/dl
• Participants must have an ionized serum calcium within normal limits
• Must meet Eastern Cooperative Oncology Group (ECOG) performance status criteria of 0-1 (0 = fully active, must be able to carry out all pre-disease activities without restriction; 1 = restricted in physically strenuous activity, but ambulatory and able to carry out work of a light or sedentary nature)
• Must be willing to attend all scheduled study visits, complete all study questionnaires, and allow biological specimen collection including a bronchoscopy within 3-4 months after enrollment into the study
• Women of child-bearing potential (i.e. women who are pre-menopausal or not surgically sterile) must use acceptable contraceptive methods (abstinence, intrauterine device [IUD], oral contraceptives or double barrier device) and must have a negative serum or urine pregnancy test within 1 week prior to beginning treatment on this trial; sexually active men must also use acceptable contraceptive methods; pregnant or nursing patients are excluded from participating in this trial; contraceptive use needs to be continued at least 1 month after the trial has ended
• Must be able and willing to sign an informed consent approved by the Institutional Review Board (IRB)

Exclusion Criteria

• Subjects with life-threatening medical conditions that would preclude bronchoscopy, including: acute cardiac failure, which is unstable despite medication use; uncontrolled hypertension; uncontrolled diabetes mellitus; or unstable coronary artery disease
• Patients with severe metabolic disorders that would preclude administration of calcitriol
• Evidence of current disease with lung cancer or head and neck cancer
• Patients may have a prior history of lung cancer or head and neck cancer treated with curative intent, provided that there has been no evidence of disease (NED) for > 1 year; the qualifying autofluorescence (AF) bronchoscopy must be negative for malignancy
• Patients with a history of any other malignancy within 3 years except non-melanoma skin and cervical carcinoma in situ (CIS)
• Patients with a history of renal lithiasis within the last 5 years or patients with evidence of kidney stones on entry evaluation
• Patients with impaired renal function creatinine clearance (CRCL) =< 60 mL/min
• Patients with hypercalcemia (using ionized calcium)
• Subjects taking calcium supplements; if subjects are willing to discontinue these supplements, there must be a 2-month wash out period before enrollment
• If patients are routinely taking a multivitamin supplement, they will be asked to continue the supplement as long as the amount of vitamin D in the supplement is not in excess of the RDA (recommended daily allowance); if they are not taking a multivitamin supplement, they will be asked to not start supplementation while on study
• Subjects with a known hypersensitivity to calcitriol
• Subjects taking thiazides (which can decrease urinary excretion of calcium)
• Patients taking phenobarbital, digitalis, thiazides or ketoconazole
• Patients taking digoxin or patients who are susceptible to calcium-related dysrhythmias
• Patients taking bile acid binding drugs (such as cholestyramine and colestipol)
• Patients taking danazol
• Patients taking aluminum-based antacids
• Oral ketoconazole or other azole antifungals
• Women who are pregnant or lactating are excluded from the study
• No known allergies to tree nuts (i.e. almonds)