Mutational profile of the KIT gene and its heterogeneity in primary and metastatic melanomas.

Background: This study investigates the mutational profile of the KIT gene in primary and metastatic melanomas, highlighting the significance of genetic heterogeneity.

Methods: This research is a retrospective cohort that includes formalin-fixed and paraffin-embedded melanoma samples obtained from Hospital São Paulo, Brazil, between the years of 1996 and 2010. The research encompasses primary melanomas of the superficial spreading (SSM) and acral lentiginous (AL) subtypes and their metastases, using next-generation sequencing to explore genetic heterogeneity.

Results: Despite losing 57 samples due to quality issues, 27 samples from 20 patients were analyzed, revealing a nearly equal distribution between AL and SSM subtypes. Both histological subtypes revealed KIT gene variants, including previously undescribed variants and polymorphisms, emphasizing the role of such mutations in melanoma pathogenesis and the potential for targeted therapies. Tumor heterogeneity was also observed in both histological subtypes.

Conclusions: The study underscores the complexity of melanoma, driven by diverse mutational landscapes within and across tumors and advocates for personalized treatment approaches based on detailed molecular profiling. Despite limitations like sample size, this research lays the groundwork for further investigation into melanoma's genetic intricacies and therapeutic vulnerabilities.