The Determination of the Relationship between Skin Toxicities and Vitamin D Level in EGFR Mutant Lung Cancer that Treated with Erlotinib

INTRODUCTION: Skin toxicities are the most common adverse events of the tyrosine kinase inhibitors that are used to EGFR mutant lung cancer. In our study, we aimed that investigated the relationship between skin toxicities and vitamin D levels in the patients with EGFR mutant and treated with erlotinib.
METHODS: EGFR mutant patients that admitted to Medical Oncology department of Atatürk Chest and Chest Surgery Hospital between 2014 – 2018 are included in this study. The patient’s data were collected retrospectively.
RESULTS: Totally, 78 patients that have EGFR mutation and treated with erlotinib are included in this study. The median level of vitamin D at the diagnosis was 34.6 (5-88) ng/ml. The patients were stratified two group according to vitamin D level. The 42 of whom (53.8 %) had vitamin D level < 20 ng/ml and 36 patients (46.2 %) had vitamin D level ≥ 20 ng/ml. Grade 2 -3 skin toxicities were significantly higher in the patients had vitamin D level < 20 ng/ml (p: 0.038).
DISCUSSION AND CONCLUSION: In our study, we found that the higher grade erlotinib related skin toxicities were more frequently in the patients that had low vitamin D level. Both of the erlotinib treatment and low vitamin D level may have contributed to the inhibition of keratinocyte proliferation, differentiation and cell cycles.

Erlotinib ile Tedavi Edilen EGFR Mutant Akciðer Kanserinde Vitamin D Düzeyi ile Cilt Toksisitesi Arasýndaki Ýliþkinin Deðerlendirilmesi

GÝRÝÞ ve AMAÇ: Epidermal büyüme faktörü reseptörü(EGFR) mutasyonu akciðer kanseri kanserinde kullanýlan tirozin kinaz inhibitörlerinin ek sýk yan etkisi cilt toksisitesidir. Çalýþmamýzda hastanemizde EGFR mutasyonu pozitif saptanan ve erlotinib tedavisi alan hastalarda serum 25(OH) vitamin D3 düzeyi ile tedavi sýrasýnda görülen cilt toksisitesi iliþikisinin deðerlendirilmesini amaçladýk.

YÖNTEM ve GEREÇLER: Ankara Atatürk Göðüs Hastalýklarý ve Göðüs Cerrahisi Eðitim ve Araþtýrma Hastanesi, Týbbi onkoloji polikliniðine 2014 – 2018 yýllarý arasýnda baþvurmuþ hastalar çalýþmaya dahil edilmiþ ve verileri retrospektif olarak toplanmýþtýr.

BULGULAR: Toplam 78 EGFR mutasyonu saptanan ve erlotinib tedavisi alan hasta çalýþmaya dahil edildi. Taný anýnda ortalama serum 25 (OH) vitamin D3 düzeyi 34,6 (5-88) ng/ml olarak saptandý. Hastalar taný anýndaki serum 25 (OH) vitamin D3 düzeyi ne göre 2 alt gruba ayrýldý. Toplam 42 (%53,8) hastanýn serum 25 (OH) vitamin D3 düzeyi 20 ng/ml in altýnda 36 (%46,2) hastanýn serum 25 (OH) vitamin D3 düzeyi 20 ng/ml in üstünde saptandý. Serum 25 (OH) vitamin D3 düzeyi 20 ng/ml in altýnda olan grupta grade 2 – 3 cilt toksisitesi daha faza olarak saptandý (p: 0.038).

TARTIÞMA ve SONUÇ: Çalýþmamýzda taný anýnda vitamin D3 eksikliði saptanan hastalarda erlotinibe baðlý yüksek gradlý cilt toksisitesi geliþme sýklýðý daha fazla saptanmýþtýr. Hem EGFR inihibisyonu hem vitamin d düzeyindeki azalma epidermiste direk olarak keratinosit proliferasyon –differensiasyon ve hücre yaþam döngüsünün inhibe olmasýna baðlý cilt toksisitesinde artýþa yol açmýþ olabilir.