Discrepancy Between Patient‐Reported and Physician‐Prescribed Chemoprevention in Patients With Keratinocyte Carcinomas

Chemoprevention is key in managing actinic keratoses and preventing the development of skin cancer, especially in individuals with cutaneous field cancerization [1]. Treatments including topical agents (5-fluorouracil [5-FU] and imiquimod), oral medications (niacinamide and acitretin), and light therapies like photodynamic therapy (PDT) target keratinocyte changes in contiguous skin areas [1]. However, patient adherence to these therapies remains challenging, often due to bothersome skin reactions [2]. This study assesses the discrepancy between patient-reported and physician-prescribed chemoprevention use in individuals diagnosed with keratinocyte carcinoma after undergoing Mohs micrographic surgery (Mohs). Participants diagnosed with keratinocyte carcinoma were recruited from an academic Mohs clinic and asked to complete an initial survey regarding demographics, skin cancer history, and chemoprevention use. Follow-up surveys were administered at 6- and 12-months post-surgery to assess the use of various chemoprevention modalities, including 5-FU, imiquimod, niacinamide, acitretin, or PDT. Patient responses were stratified by age, gender, and baseline chemoprevention use and compared to physician prescriptions using statistical analyses (chi-square, Fisher's exact, Wilcoxon Rank Sum, or independent samples t-tests.). Discordant responses were further analyzed using McNemar's tests to determine whether underreporting (incorrectly reporting no use) or overreporting (reporting use when not prescribed) was more common. A total of 227 and 180 participants completed the chemoprevention surveys at 6- and 12-months, respectively. At 6 months, there were approximately equal numbers of male (n = 116) and female (n = 111) participants, with an average age of 68.7 years. Most respondents were White (n = 225) and had no prior history of chemoprevention (n = 175). While most patients accurately reported chemoprevention use (79.7% at 6 months; 81.7% at 12 months), patients were more likely to underreport (14.1%) than overreport (6.2%) chemoprevention use at 6 months (p = 0.01) (Table 1). A similar trend was observed for 5-FU and niacinamide use at 6 months (p < 0.01). Older patients ( x ¯ $$ \overline{x} $$ = 73.0 years, σ = 8.8) were more likely to misreport 5-FU use at 6 months compared to younger patients ( x ¯ $$ \overline{x} $$ = 67.9 years, σ = 11.6) (p = 0.01) (Table 2). Male patients showed greater discrepancies in 5-FU reporting at 6 months compared to female patients (21.6% vs. 11.7%, p = 0.047). Compared to patients without a history of chemoprevention treatment, those with prior chemoprevention use were more likely to misreport their use at 6 months, including for any chemoprevention (32.7% vs. 16.6%, p = 0.01), 5-FU (30.8% vs. 12.6%, p = 0.002), and acitretin (5.8% vs. 0.0%, p = 0.01). At 12 months, patients with prior chemoprevention use were also more likely to misreport niacinamide (22.7% vs. 6.6%, p = 0.003) and acitretin use (6.8% vs. 0.0%, p = 0.01). This is the first study comparing patient-reported chemoprevention use with physician prescriptions. Most patients accurately reported chemoprevention use, reflecting effective institutional education. However, reporting discrepancies highlight an opportunity to improve adherence and health literacy surrounding chemoprevention across certain patient groups. Limitations of this study include potential response bias due to approximately 50% of patients not completing the 6- and 12-month follow-up surveys. Inaccurate reporting was more common among patients with prior chemoprevention use, possibly due to nonadherence resulting from previous undesirable skin reactions or lack of perceived treatment efficacy [3]. A more thorough discussion of side effects and the importance of continued use could encourage adherence in this group. In our experience, patients with excess 5-FU after completing their prescribed treatment often use it for spot treatment at their discretion, which may explain reports of 5-FU use without a physician's recommendation. Older patients also showed greater discrepancies in reported chemoprevention use compared to younger individuals. Factors contributing to non-adherence in this population may include social isolation, cognitive decline, or limited access to technology for receiving patient instructions via platforms like MyChart [2-4]. Addressing these challenges by increasing caregiver support and providing communication through hard-copy summaries may help mitigate these issues [5]. Approved by UNMC IRB no. 0630-18-EP. Patient consent was obtained. The authors declare no conflicts of interest.