This study has been on hold due to the COVID-19 pandemic. Recruitment never began and the team didn't renew the study

Actinic cheilitis is a condition of the lower lip characterized by grayish-white areas of discoloration and blunting of the demarcation between the cutaneous lip and the mucosa.

While many studies have compared treatment options for actinic cheilitis, there is still significant debate over how to best manage this condition. The chosen treatment regimen must result in complete remission while also preventing recurrence and malignant transformation. Current treatment options are vast, including both non-surgical and surgical options. Common topical therapies include 5-fluorouracil, imiquimod, ingenol mebutate and diclofenac. More recently, photodynamic therapy has been brought forward as a potential treatment modality. From a surgical perspective, a vermilionectomy is typically the procedure of choice.

TCA is a popular topical treatment for treat fine rhytides, hyperpigmentation, photodamage, and premalignant changes, such as actinic keratoses. Despite this, TCA is not commonly used for actinic changes on the lips. Here, the investigators propose an expansion of the application of TCA to be used in the treatment of actinic cheilitis.

The proposed study will be a prospective cohort study of all patients with actinic cheilitis presenting to the study institution, the Queen Elizabeth II Health Science Center in Halifax, from March 1st 2021- March 1st 2023.

Patients will be consented to participate at the time of their initial consultation. They will fill out the demographics form, a preliminary survey and have the required photographs taken on that same day. A biopsy will be performed prior to treatment to establish the histological grade of their actinic cheilitis based on the degree of dysplasia. After the treatment is received, they will follow-up in 1 month for reassessment. At this point, a second treatment will be offered if clinical remission has not been achieved. Patients will continue TCA treatments at 1-month intervals until clinical remission is reached. Once remission is achieved, they will fill out the post-treatment questionnaire and have their second set of photos taken.

Final follow-up will occur 6 months post remission. At this point patients will be assessed for clinical recurrence. A third set of photos will be completed during this appointment.

Inclusion Criteria:

• Inclusion criteria will include all patients with actinic cheilitis that do not meet exclusion criteria.

Exclusion Criteria:

• Exclusion criteria will include patients younger than 18 years of age and patients with a biopsy proven malignancy of the lip.

Participant data will not be used outside the confines of this study.