Association of increased body height with BRAF mutations in male melanoma patients.

Abstract

e20032 Background: Somatic BRAF mutations occur in approximately 40-50% of patients (pts) with unresectable cutaneous melanoma (CM) and are more common in young pts. The objective of this study was to determine if body height and body mass index (BMI) are associated with BRAF mutation status. Methods: 212 consecutive BRAF-tested patients with unresectable stage IIIC or IV CM were analysed. Tumor samples from two departments of dermatology were screened by high-resolution melt curve analysis of BRAF exon 15; abnormal results were confirmed by DNA sequencing. Associations between BRAF mutation status and height, BMI and age of pts were examined using univariate and multivariate logistic regression analyses in the whole sample and according to sex. Results: The BRAF mutation frequency was 42%. On univariate analysis in the whole sample, BRAF mutated status was not associated to BMI (p=0.9) but was associated to age and height (p≤0.027). The BRAF mutation frequency was higher in taller pts reaching 59% in pts > 180 cm (p=0.003, χ² test). According to sex, this association was significant in males (p=0.004) but not in females (p=0.39). Size did not differ significantly in the 4 quartiles groups of age (<50, 50-62, 62-72 and >72 years; p >0.07). On multivariate analysis, in the whole sample, only age was associated to mutated BRAF status (p<0.001); but in the male subgroup, age and height were independent factors predicting BRAF mutations (p<0.04). Conclusions: Tallness was significantly associated with BRAF mutations in male melanoma pts. This is in agreement with published data for colorectal carcinoma. This study might suggest a genetic susceptibility to somatic BRAF mutations, increased height and melanoma. [Table: see text]