RATIONALE: Chemoprevention is the use of certain drugs to keep cancer from forming. The use of eflornithine and diclofenac may stop cancer from growing in patients with sun-damaged skin.

PURPOSE: This randomized phase II trial is studying the side effects and how well eflornithine works compared with diclofenac, given alone or together, in treating patients with sun-damaged skin.

OBJECTIVES:

Primary

• To determine if combination therapy with topical eflornithine hydrochloride ointment and topical diclofenac sodium gel over 3-months increases the efficacy versus either agent used alone in the treatment of moderately sun-damaged skin.

Secondary

• To evaluate the safety of sequential administration of topical eflornithine hydrochloride ointment and topical diclofenac sodium gel.
• To determine the correlation of karyometric changes with histopathologic, immunohistochemical, clinical, and genetic polymorphism data.
• To obtain materials for microarray analysis.

OUTLINE: Patients are randomized to 1 of 3 treatment arms.

• Eflornithine hydrochloride : Patients apply topical eflornithine hydrochloride ointment to their left forearm twice daily on days 1-90.
• Diclofenac sodium : Patients apply topical diclofenac sodium gel to their left forearm once daily on days 1-90.
• Eflornithine hydrochloride/Diclofenac sodium : Patients apply topical eflornithine hydrochloride ointment as in arm I twice daily and topical diclofenac sodium gel as in arm II once daily on days 1-90.

Prior to treatment, three 4-mm punch biopsies are taken from the skin of the left lateral forearm for assessment of histopathology, the cyclooxygenase-2 enzyme and p53 expression, apoptosis, and nuclear chromatin karyometry. Tissue is also obtained for future use in microarray analysis. Blood is drawn for assessment of ornithine decarboxylase polymorphisms and for banking for subsequent studies. Biopsies are repeated 2-3 weeks after completion of treatment.

Digital photographs are taken at baseline and 1-2 weeks after completion of study therapy to document improvement of sun damage, appearance of new skin lesions, and toxicity.

Inclusion Criteria:

• Visible sun-induced damage to the skin as assessed by the study dermatologists
• No inflammation of the skin on the lateral forearms
• No more than 10 actinic keratoses on the left forearm, and no actinic keratoses in the treatment area
• Resident of Pima or an adjoining Southern Arizona county
• History of treated basal cell carcinoma and/or squamous cell carcinoma of the skin at any site other than the left forearm allowed if excision or topical treatment was completed more than 30 days ago (60 days for radiotherapy)
• History of treated basal cell carcinoma and/or squamous cell carcinoma of the skin on the left forearm allowed 6 months after treatment is completed
• Must agree to avoid sun exposure to the left forearm as much as possible
• Not pregnant or nursing
• Not moderately to highly immunosuppressed by virtue of medication or disease, except for mildly suppressive disorders (e.g., diabetes mellitus or on mildly immunosuppressive therapy such as inhaled steroids for asthma)
• No serious concurrent illness that could interfere with study participation
• No active peptic ulcer disease, bleeding disorder, renal failure (creatinine > 2.0 mg/dL), or porphyria
• No known hypersensitivity to diclofenac sodium, eflornithine, acetylsalicylic acid, or NSAIDS
• No evidence of serious underlying medical conditions as demonstrated by abnormal values on baseline laboratory assessment
• More than 6 months since prior chemotherapy and in complete remission
• More than 60 days since prior and no concurrent oral diclofenac sodium (Cataflam®, Voltaren®, Voltaren-XR®) or combination of diclofenac and misoprostol (Arthrotec®)
• More than 60 days since prior and no concurrent IV eflornithine hydrochloride
• More than 30 days since prior and no concurrent topical retinoids, steroids, imiquimod (Aldara®), aminolevulinic acid HCl (Levulan®), eflornithine (Vaniqa®), diclofenac sodium gel (Solaraze®), or fluorouracil at any site
• More than 30 days since prior and no concurrent topical medication, other than emollients or sunscreens, on the left forearm
• Not undergoing concurrent bone marrow or solid organ transplant
• No concurrent immunosuppressive therapy (e.g., systemic chemotherapy or rheumatologic agents such as infliximab [Remicade®])
• No concurrent sunscreen use to the left forearm
• No concurrent active therapy for any invasive cancer
• No concurrent NSAIDs for more than 14 days per month for arthritic and other pain conditions
• Concurrent prednisone or other steroids with doses up to 20 mg/day (or the equivalent dose) allowed
• At least 30 days since prior and no concurrent enrollment on other investigational drug or device trial

Exclusion Criteria:

• Individuals receiving concurrent topical therapy with retinoids, steroids, 5-fluorouracil, Levulan, Vaniqa (eflornithine), Solaraze, or Imiquimod (Aldara®) within 30 days prior to study enrollment will be excluded. Subjects may be reconsidered for eligibility 30 days after the last topical treatment.
• Individuals who have had treatment for basal cell carcinoma or squamous cell carcinoma of the skin of the left forearm within six months prior to evaluation for the study will not be eligible. If interested, these subjects will be encouraged to return for re-evaluation once the six-month period is over.
• Individuals who are moderately to highly immunosuppressed by virtue of medication or disease will not be allowed to participate. This category includes individuals undergoing bone marrow or solid organ transplant, or receiving immunosuppressive therapy such as systemic chemotherapy or rheumatologic agents such as infliximab (Remicade®). However, individuals with mildly suppressive disorders such as diabetes mellitus or on mildly immunosuppressive therapy such as inhaled steroids for asthma will be eligible for participation. Doses up to 20 mg of prednisone per day or the equivalent dose of other steroids will be allowed.

Three months