Facial Skin With Conspicuous Enlarged Pores Closely Related to Severity of Facial Acneiform Rash and Therapeutic Effects of EGFR Inhibitors in RAS Wild-Type Metastatic Colorectal Cancer: Ancillary Analysis of FAEISS Study (NCCH1512).

Prophylactic treatment with oral minocycline or doxycycline, moisturizers, and sunscreens has been reported to be beneficial for acneiform rash (AfR) caused by epidermal growth factor receptor (EGFR) inhibitors. It is desirable to predict which patients may develop severe AfR and provide prophylactic treatment. This study aimed to evaluate the association between the worst grade of facial AfR (FAfR) after initiating therapy with EGFR inhibitors and the characteristic skin type in patients with RAS wild-type metastatic colorectal cancer enrolled in the FAEISS study (a phase III, open-label, randomized trial evaluating topical corticosteroids for Facial Acneiform dermatitis by EGFR Inhibitors: Stepwise rank down from potent corticosteroids). Using pretreatment photographs of the face, characteristic skin types, including enlarged pores, oiliness (greasiness), and skin color/redness, were graded on a scale of 1-3. Grade 2 or higher FAfR developed in 9.1%, 27.0%, and 45.8% of patients with enlarged pore scores of 1, 2, and 3, respectively. Patients with enlarged pores tended to have more severe FAfR (p = 0.0216). Moreover, the disease control rate (complete remission/partial remission/stable disease) of the primary disease was seen in 59.1%, 70.6%, and 87.0% of patients with an enlarged pore score of 1, 2, and 3, respectively, showing a statistically significant trend (p = 0.038). This study suggests that a facial skin type with a high number of enlarged pores may be a marker for predicting AfR risk due to anti-EGFR antibody therapy and better therapeutic effects for RAS wild-type metastatic colorectal cancer.