Akademik Veri Yönetim Sistemi
34th EADV Congress , Paris, Fransa, 17 - 20 Eylül 2025, cilt.2, ss.182-183, (Özet Bildiri)
Introduction & Objectives: Ribociclib, a cyclin-dependent kinase 4 and 6 inhibitor, is an antineoplastic agent used in the first-line treatment of hormone receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer in combination with an aromatase inhibitor. Hematologic side effects are common during treatment, but cutaneous adverse effects such as alopecia, pruritus, skin rash, and, rarely, vitiligo-like lesions have also been reported. Materials & Methods: Herein, we present a female patient with metastatic hormone receptor-positive, HER2-negative breast cancer who developed vitiligo-like skin lesions during ribociclib therapy, diagnosed based on the clinical findings. Results: A 69-year-old female patient presented to our clinic with a 5-month history of pruritus over the legs, followed by vitiligo-like lesions on the elbows and legs. The patient had previously undergone modified radical mastectomy, followed by adjuvant chemotherapy with cyclophosphamide, doxorubicin, and paclitaxel with a diagnosis of hormone receptor-positive, HER2-negative breast cancer. After lung and bone metastases were detected, she received ribociclib in combination with letrozole for 8 months. She had no personal or family history of autoimmune disease. She did not described trauma. A dermatological examination revealed symmetrical hypopigmented macules and patches with erythematous borders on the arms, forearms, hands, thighs, legs, and feet. Wood’s light examination showed sharply demarcated depigmented lesions. Based on the history and clinical findings, the diagnosis of ribociclib-induced vitiligo-like lesions was made. According to the World Health Organization Causality Assessment Scale and the Naranjo Adverse Drug Reaction Probability Scale, the case was classified as a “probable” adverse drug reaction. Treatment included topical corticosteroids and topical tacrolimus, along with photoprotection. However, we did not observe a significant response to the treatment, likely due to the continuation of ribociclib therapy. Conclusion: Vitiligo-like lesions, unlike vitiligo, are characterized by Koebner-negative, depigmented macules on sun-exposed areas. Although the pathogenesis is not fully understood, they have been reported as side effect during oncological treatment, including tyrosine kinase inhibitors, and PD1 inhibitors. Ribociclib acts as a cyclin-dependent kinase 4 and 6 inhibitor, thereby blocking the progression from the G1 to the S phase of the cell cycle. Ribociclib-induced cell cycle arrest may culminate in the premature death of melanocytes, manifesting as depigmented lesions. Depigmented lesions typically follow pruritus and erythema in both sun-exposed and non-sun-exposed regions, and involving more than 25% of the body surface area. Topical corticosteroids and calcineurin inhibitors remain the prevailing treatment modalities, though ribociclib-induced vitiligo-like lesions have been reported to be more resistant to treatment than vitiligo. In a previously reported case series, tumor regression coincided with the development of vitiligo-like lesions in 12 out of 14 patients, suggesting a potential favorable prognostic indicator. Further research is needed to better understand the implications of ribociclib-induced vitiligo-like lesions. Nonetheless, recognizing and managing this adverse effect is essential due to its potential impact on patients’ quality of life.