Association between clinicopathologic characteristics and BRAFV600E expression in Chinese patients with Langerhans cell histiocytosis

Abstract

Background The identification of V‐raf murine sarcoma viral oncogene homolog B1 (BRAF)V600E mutations has been recommended in patients with Langerhans cell histiocytosis (LCH) with difficult diagnosis and failure of first‐line treatment. The reported frequencies of BRAFV600E mutations vary in Chinese patients with LCH. Methods We conducted a retrospective analysis of LCH patients with a definitive pathological diagnosis who were hospitalized between 2013 and 2017. The BRAFV600E mutations were detected with the human BRAFV600E amplification refractory mutation system‐PCR (ARMS‐PCR) kit from the collected tissue samples. Results This study consisted of 46 male (68.7%) and 21 female (31.3%) patients, with a mean age of 29.1 years (range, 2–76 years). Most were adults (45/67.2%) with the multisysytem‐LCH (MS‐LCH) disease subtype (49/61.3%). The overall frequency of BRAFV600E mutations was 22.4% (15 of 67 patients), confirmed by PCR analysis. These mutations were not closely correlated with age (nonadults vs. adults = 5/22.7% vs. 10/22.2%, P = 0.54), gender (female vs. male = 9/19.6% vs. 6/28.6%, P = 0.61), LCH classification type (single system: MS‐risk organ+: MS‐risk organ− = 3/16.7%: 12:28.6%: 0, P = 0.19) or prognosis (cured: improved/stable: exacerbated: died = 4/44.4%: 19.2%: 20%: 0, P = 0.37). There were 33 patients (49.2%) with lung involvement, and 12 patients (36.3%) underwent lung biopsies; after screening, four patients were diagnosed with solitary pulmonary LCH, all of whom were negative for BRAFV600E mutations. Conclusion The BRAFV600E mutation rate in patients with LCH was lower than those reported in other studies. In addition, BRAFV600E mutations might not be correlated with age, gender, LCH classification type or prognosis for Chinese cases.

Keywords

• BRAF
• Langerhans cell histiocytosis
• mutation
• pulmonary
• V600E