Abstract:

Chai Li *, Kang Xiaojing, Sun Zhenzhu, Gao Feng, Shi Xiaohui, Yu Shirong, Chen Wenjing, Wu Xiujuan, Ding Yuan, Liang Junqin, Liu Wenxian, Pu Xiongming. *Xinjiang Medical University, Urumqi 830001, China Corresponding author: Kang Xiaojing, Email: drkangxj666@163.com 【Abstract】 Objective To analyze clinical characteristics of and c-kit gene mutations in Uygur patients with mucosal melanoma, and to explore the relationship between c-kit gene mutations and clinical characteristics of mucosal melanoma. Methods Clinical data were collected from 31 Uygur patients with pathologically confirmed mucosal melanoma. DNA was extracted from paraffin-embedded melanoma tissue samples from these patients. Then, PCR and direct DNA sequencing were performed to detect c-kit gene mutations. Statistical analysis was carried out by using Fisher′s exact test. Results Of the 31 Uygur patients, the male/female ratio was 1 ∶ 1.2, and the average age was 61.35 years. The incidence of mucosal melanoma was highest in the age group of 20 - 44 years, followed by the age group of 51 - 59 years. Head and neck, especially nasal mucosa, were the most common sites affected by mucosal melanoma, followed by genitourinary and rectal mucosa. C-kit gene mutations were detected in 4 （12.9%, 4/31） out of the 31 mucosal melanoma cases, which were located in exon 11 and included L576P mutation in 3 cases and W557R mutation in 1 case. Of the 4 patients carrying C-kit gene mutations, 3 had rectal mucosal melanoma and 1 urethral mucosal melanoma. The frequency of c-kit gene mutations was 3/7 in patients with rectal mucosal melanoma and 4.17% （1/24） in those with melanoma at the other mucosal sites. Additionally, the frequency of c-kit gene mutations was significantly higher in patients with lymph node metastasis than in those without （P = 0.043）, but similar between male and female patients or between different age groups （both P > 0.05）. Conclusions Mucosal melanoma mainly occurs in the elderly in Uygur population, with mucosa of the head and neck as the predilection sites. Mutations of the c-kit gene are closely associated with the site and lymph node metastasis of mucosal melanoma.