What is the ideal treatment for Bowen disease?

Treatment of Bowen's Disease: A Comprehensive Approach

Photodynamic therapy (PDT) is the ideal treatment for Bowen's disease, particularly for large lesions (>3cm) and those on poor healing sites like the lower leg. 1, 2

Treatment Selection Based on Lesion Characteristics

The optimal treatment approach for Bowen's disease (squamous cell carcinoma in situ) depends on several factors including:

• Size and number of lesions
• Location
• Healing potential of the site
• Patient factors

First-line Treatment Options by Lesion Characteristics:

Small, Single Lesions on Good Healing Sites:

1. Curettage with cautery - Simple, inexpensive, effective with faster healing and less pain than cryotherapy 1
2. Cryotherapy - Effective but with longer healing time 1, 2
3. Surgical excision - Effective for limited size lesions in suitable areas 1

Large Lesions (>3cm):

1. PDT - Most effective with superior cosmetic outcomes 1, 3
2. Topical 5-fluorouracil (5-FU) - Applied once or twice daily for 3-4 weeks 1, 4
3. Topical imiquimod - 5% cream, though currently unlicensed for this indication 1

Multiple Lesions:

1. Cryotherapy - Good for treating multiple small lesions 1
2. PDT - Particularly useful for multiple lesions 1, 2
3. Topical 5-FU - Practical for multiple lesions 1

Poor Healing Sites (e.g., Lower Leg):

1. PDT - Treatment of choice with superior healing 1, 2
2. Topical 5-FU or imiquimod - Good alternatives 1
3. Avoid radiotherapy - Poor healing on lower leg 1

Special Sites:

Facial:

• Cryotherapy or curettage preferred 1
• Consider cosmetic outcome

Digital:

• Mohs micrographic surgery for tissue preservation 1
• PDT or topical 5-FU as alternatives 1

Perianal:

• Wide surgical excision - Lower recurrence rate (23.1%) compared to local excision (53.3%) 1, 5
• Radiotherapy as second-line option 1

Penile:

• Consider Mohs micrographic surgery 1
• PDT or topical treatments as alternatives 1

Efficacy Comparison

1. PDT:

   • 75% clearance after single treatment vs. 50% for cryotherapy 2
   • 90% complete clinical response for extensive lesions 3
   • Superior cosmetic outcomes 2, 3

2. Surgical excision:

   • 97.4% sustained clearance at 12 months 4
   • 5mm margins achieve 94.4% complete excision rate 6

3. Topical 5-FU:

   • 85.7% sustained clearance at 12 months 4
   • Better cosmetic outcome than excision 4

4. Cryotherapy:

   • ~10% recurrence rate at 12 months 2
   • Associated with more adverse effects including ulceration (25%) and scarring (20%) 2

Treatment Techniques

PDT Protocol:

• Apply methyl aminolevulinate cream for 3 hours
• Illuminate with LED light source (630nm wavelength)
• Repeat treatment 1 week later 3

Cryotherapy Technique:

• Single freeze-thaw cycle of 30 seconds, or
• Two freeze-thaw cycles of 20 seconds with thaw period, or
• Up to three single treatments of 20 seconds at intervals of several weeks 2

5-FU Application:

• 5% cream applied once or twice daily for 3-4 weeks
• May require repeat cycles for complete clearance 1

Important Considerations

• Risk of progression: Approximately 3% risk of progression to invasive squamous cell carcinoma, with higher risk in genital and perianal disease 1, 7

• Follow-up: Longer follow-up (>5 years) recommended for perianal disease due to risk of late recurrence 5

• Elderly patients: For slowly progressive thin lesions in elderly patients, especially on the lower leg, observation may be reasonable 1

• Recurrence rates: Higher with conservative treatments, particularly for perianal disease 5

PDT offers the best balance of efficacy, cosmetic outcome, and healing for most cases of Bowen's disease, particularly for challenging locations and larger lesions 1, 2, 3.