Topical chemotherapy

5-fluorouracil (Efudix)

• Stops DNA replication - cytotoxic
• Indications:
  • Actinic or solar keratoses
  • Superficial BCC
  • SCC in situ - somewhat off-label use
• Limit treatment area to size of face - larger area possible than imiquimod
• Apply once or twice a day after washing with water
• Three-week regimen for facial skin. Can do longer, especially for SCC-in-situ.
• Practice strict sun protection. Can put on bland moisturiser 20 minutes after.
• Expect to develop an inflammatory reaction by day 5-7.
• Need to re-review at two weeks to ensure the patient isn't over-applying, which can lead to severe inflammation/necrosis
• If the skin gets a bit over-treated, use steroid creams and moisturisers to pull it back

Imiquimod (Aldara)

• Immunotherapy - toll-like receptor 7 agonist
• Indications
  • Actinic keratoses
  • Superficial BCC
  • Cutaneous SCC-in-situ - off label
  • Cutaneous flat warts
  • Genital and perianal warts
  • Lentigo maligna - off-label!
• Regimes
  • Actinic keratosis - 2-3x weekly for 4-6 weeks, then with a 4-week break and repeated
  • BCCs and SCC in-situ - 5x weekly for 6 weeks
  • But titrate usage to reaction
• Only available on PBS for biopsy-proven superficial BCC unsuitable for excision, and solar keratosis on face/scalp field therapy