From the Guidelines
The recommended treatment regimen for Bowen's disease using imiquimod typically involves applying 5% imiquimod cream to the affected area once daily, 5 days per week, for a period of 6-16 weeks, as supported by the most recent and highest quality study 1.
Key Considerations
- The treatment duration depends on clinical response, with regular follow-up evaluations recommended to assess efficacy and manage side effects.
- Patients should expect local skin reactions including redness, swelling, erosion, and crusting as these indicate the desired immune response is occurring.
- These reactions typically peak after 2-4 weeks of treatment.
- Imiquimod works by stimulating the innate immune system through Toll-like receptor 7, producing cytokines that promote a cell-mediated immune response against abnormal cells.
Treatment Application
- The cream should be applied to clean, dry skin, covering the lesion and a small margin of surrounding normal skin.
- It should remain on the skin for 8 hours before being washed off with mild soap and water.
Patient Selection
- This treatment is particularly useful for patients with multiple or large lesions, those in cosmetically sensitive areas, or individuals who are poor surgical candidates.
- Treatment should be temporarily suspended if severe local skin reactions develop, resuming once the reaction subsides, as noted in earlier guidelines 1 and further supported by later studies 1.
Evidence Base
- The evidence base for imiquimod in treating Bowen's disease includes small randomized trials and open studies, with the most significant support coming from a study demonstrating 73% histologically proven resolution with imiquimod versus zero response in the placebo group 1.
- Later guidelines continue to support the use of imiquimod, although they also highlight the need for further investigation into the ideal dosing regimen and cost-effectiveness 1.
From the Research
Imiquimod Treatment for Bowen's Disease
- The recommended dose of imiquimod for treating Bowen's disease of the skin is 5% cream, applied topically 2, 3, 4, 5.
- The treatment regimen varies, with some studies using once-daily self-application for 16 weeks 3, while others use a cycle regimen of three times weekly for 3 weeks followed by a 4-week rest period 5.
- Imiquimod 5% cream has been shown to be an effective treatment for Bowen's disease, with a positive treatment response in 93% of biopsy-proven cases 3 and complete clinicopathologic regression in 80% of lesions 4.
- However, the recurrence rate for imiquimod treatment has been reported to be as high as 33.33% 6, highlighting the need for careful monitoring and follow-up.
Treatment Outcomes
- Studies have reported successful treatment of Bowen's disease with imiquimod 5% cream, with no residual tumor present in post-treatment biopsy specimens in 93% of cases 3.
- Imiquimod treatment has also been shown to reverse the CD4/CD8 lymphocyte ratio in post-treatment biopsy specimens, indicating a shift in the immune response 3.
- The treatment period for imiquimod has been reported to be longer than other treatment modalities, such as surgical excision and photodynamic therapy 6.