Topical Vitamin C for Treatment of Basal Cell Cancer
Condition: Basal Cell Carcinoma
MeSH terms: Carcinoma; Carcinoma, Basal Cell
Study type: Interventional
Phase: Early Phase 1

Summary: 
      Randomized coomparative trial of a 30% solution of ascorbic acid in 95% dimethylsulfoxide
      applied topically twice a day for 8 weeks vs 5% imiquimod cream in the treatment biopsy
      proven basal cell carcinomas inotherwise healthy adult patients. Outcome measure was biopsy
      proven resolution of the carcinoma.
    

Detailed description: 
      Importance

      Skin cancer is the most common cancer in the United States, with more people diagnosed each
      year than all other cancers combined (1). Basal cell cancer is the most common form with an
      estimated 4.3 million cases diagnosed annually (2,3). Costs of treating this cancer in the
      U.S. are estimated at $4.8 billion annually (4). Task force consensus guidelines suggest Mohs
      surgery as the treatment of choice, and as the single most precise and effective treatment
      method (5). However, cost and issues of cosmesis are principal disadvantages.

      Objective

      To evaluate efficacy of a therapeutic regimen in treating basal cell cancer, consisting of
      30% ascorbic acid in 95% dimethylsulfoxide topically applied at home by patients twice a day
      for 8 weeks, vs 5% imiquimod cream which is an FDA approved treatment for BCC.

      Design, Setting, and Participants This study was carried out in accordance with principles of
      the Declaration of Helsinki. Detailed informed consent was obtained from each patient.

      Eligible participants of any age had histologically confirmed primary, previously untreated,
      nodular or superficial BCC not arising at sites of high risk for sub clinical tumor spread
      (the nose, ear, eyelid, eyebrow, or temple ( )). Patients with infiltrative, recurrent, or
      morphoeic BCC were excluded from the study. Imiquimod was applied once daily for 5 days per
      week as per manufacturer instructions for treatment of BCC. Patients were randomly assigned
      to treatment group. Participants and outcome assessors were blinded to treatment protocol.
      Patients were seen at initial visit, 4 weeks, 8 weeks, and six weeks after treatment
      conclusion for final biopsy. Those participants in the IMQ group who continued through 12
      weeks of treatment were seen for an additional visit. The AA treatment was a solution while
      the IMQ a cream, however participants were simply told they would be receiving a topical
      treatment with instructions on how to apply, thus the blinding remained intact.

      Histopathology showed 21 nodular and 8 superficial BCC subtypes upon enrollment. Thirteen
      patients (8 female 5 male) with a total of 15 lesions were randomized to the ascorbic acid
      (AA) treatment group, and 12 patients (6 female 6 male) with 14 lesions were randomized to
      the imiquimod group (IMQ). There was no difference in mean size of BCC in each group ( 11.4
      +/-2.1 mm vs. 13.1 +/- 1.9mm). The AA group had 11 nodular and 4 superficial BCC and the IMQ
      group 10 nodular and 4 superficial.

      Histopathology was confirmed by 2mm partial punch biopsy leaving

      the bulk of the BCC intact prior to treatment. Patients in the AA group were treated

      twice daily 7 days per week with a topical solution of 30% (w/v) ascorbic acid solution in
      95% (v/v) dimethylsulfoxide (DMSO) and

      5% (v/v) distilled water, while the IMQ patients received twice daily application of a
      commercial 5% cream 5 days per week according to manufacturer recommendations for treatment
      of BCC. Application was made with a small cuticle brush in the AA group. Patient compliance
      was high and no

      patient had difficulty with the application. Volume of the ascorbic acid solution applied was
      0.2-0.3ml per application. Treatment was

      continued for 8 wks or until the lesion cleared. Subjects in the IMQ group whose lesions had
      failed to resolve at 8 weeks were treated for an additional 4 weeks in conformity with
      reports showing better outcomes with 12 weeks of treatment with IMQ ( ).

      All patients had an appointment set for Mohs surgery

      after study enrollment, so in the event of treatment failure no further delay in definitive
      treatment would occur.

      Repeat 2mm punch biopsy of each site was taken at the conclusion of the study. Patients were
      seen in follow up after

      12, 24, and 30 months

      Interventions

      An 8 wk therapeutic regimen of topical 30% (w/v) ascorbic acid, 95% (v/v) dimethylsulfoxide,
      and 5% (v/v) distilled water applied twice daily at home, or 5% imiquimod cream applied 5/wk
      according to manufacturer recommendations for treating BCC.

      Main Outcomes and Measures

      Number of lesions out that were cancer free after 8 wks of treatment.
    

Intervention name(s): Topical Ascorbic Acid
Intervention type(s): Drug
Intervention description(s): Twice daily application of 300 microliters of 30% ascorbic acid solution with a small cuticle brush.
Intervention MeSH terms: Ascorbic Acid
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment