Clinical Characteristics of Malignant Melanoma in Southwest China: A Single-Center Series of 82 Consecutive Cases and a Meta-Analysis of 958 Reported Cases

RESEARCH ARTICLE Clinical Characteristics of Malignant Melanoma in Southwest China: A SingleCenter Series of 82 Consecutive Cases and a Meta-Analysis of 958 Reported Cases Jia Yu1☯, Xue Luo2☯, Hui Huang1, Zhifang Zhai1, Zhu Shen1*, Hui Lin2* a11111 1 Department of Dermatology, Southwest Hospital, Third Military Medical University, Chongqing, 400038, People’s Republic of China, 2 Institute of Tropical Medicine, Third Military Medical University, Chongqing, 400038, People’s Republic of China ☯ These authors contributed equally to this work. * (HL); (ZS) Abstract OPEN ACCESS Citation: Yu J, Luo X, Huang H, Zhai Z, Shen Z, Lin H (2016) Clinical Characteristics of Malignant Melanoma in Southwest China: A Single-Center Series of 82 Consecutive Cases and a MetaAnalysis of 958 Reported Cases. PLoS ONE 11 (11): e0165591. doi:10.1371/journal. pone.0165591 Editor: Andrzej T Slominski, University of Alabama at Birmingham, UNITED STATES Received: January 30, 2016 Accepted: October 16, 2016 Published: November 18, 2016 Copyright: © 2016 Yu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper. Funding: The authors received no specific funding for this work. Competing Interests: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper. The authors declared that they have no financial and personal relationships with other people or organizations that can inappropriately Purpose The present study determined the clinical characteristics and prognostic factors in patients with malignant melanoma based on a series of 82 cases from January 2009 to December 2014 in Southwest Hospital and a meta-analysis (including 12 articles) involving 958 patients in China. Materials and methods The database elements included basic demographic data and prognosticators which were extracted from medical records. Statistical analyses of survival, and multivariate analyses of factors associated with survival were performed using the Kaplan—Meier method, and the Cox proportional hazard model, respectively. Literatures were identified through systematic searches in PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure (CNKI) and Weipu database (VIP) database for the period from inception to December 2015. The meta-analysis was conducted using R 3.1.1 meta-analysis software Results In this series of 82 cases, the median age of the patients was 57.50 years. Melanoma was located in the foot in 79% of patients. Sixty-one patients (74.4%) were classified as stage IIIII. Thirty-two patients (39.0%) had acral malignant melanoma, and 31 patients (37.8%) had nodular malignant melanoma. The clinical characteristics of melanoma were similar to those in areas outside southwest China (from results of the meta-analysis). The median survival time was 29.50 months. The 1-year, 3-year, and 5-year survival rates were 84.1%, 39.0% and 10.9%, respectively. COX regression following multi-factor analysis showed that ulcer, tumor boundary and lymph node metastasis were associated with prognosis. PLOS ONE | DOI:10.1371/journal.pone.0165591 November 18, 2016 1 / 23 Characteristics of Melanoma in China influence their work. There is no professional or other personal interest of any nature or kind in any product, service and/or company. Conclusions The clinical characteristics of melanoma in Chinese were different from those in Caucasians. Ulcer, tumor margins, and lymph node metastasis were significantly associated with prognosis. Immune therapy may prolong the median survival time of patients with acral melanoma, nodular melanoma, or stage I-III disease, although these differences were not statistically significant. Introduction Malignant melanoma is derived from neural crest melanocytes and is frequently found in the skin, digestive tract, eyes, genitals and nasal cavity. The highest incidence of malignant melanoma is found in the skin. Early local and distant metastasis, and poor prognosis are clinical characteristics of malignant melanoma [1]. There are clear demographic and ethnic differences in malignant melanoma, such as incidence, etiology, and clinical characteristics [2]. Malignant melanoma is a common malignancy, and is frequently found in fair-skinned people in Western countries. The highest incidence of malignant melanoma is in Queensland, Australia [3]. As melanin is presented in the skin, the incidence of malignant melanoma is less frequent in Africa, Spain and Asia. However, if the populations in these areas developed malignant melanoma, their survival time would be significantly lower than that in Caucasians [4–6]. The incidence of melanoma in China was relatively low, accounting for 1%–3% among that of all malignant tumors. However, the number of new cases in China each year is more than 20,000 [7], and currently has the highest incidence in all malignant tumors, with an annual growth rate of approximately 3% -5% [8]. There is a huge difference in the pathogenesis and clinical characteristics of melanoma between Chinese and Caucasians. Firstly, the causes are different. Melanoma in Caucasian occurs in areas with excessive ultraviolet radiation. The etiology is associated with skin color and ultraviolet radiation intensity [9]. Melanoma in Chinese mainly occurs in the extremities. The cause remains unclear. Clinical experience has shown that improper processing (local stimulation by knife, salting, freezing, laser etc.) is an important factor inducing malignant nevi [8]. Secondly, the pathological types are different. Melanoma in Caucasians occurs in body skin, and the most common type is superficial spreading type [10]. Malignant melanoma in Chinese is mostly acromegaly and mucosal melanoma type [8]. Thirdly, the majority of Caucasian patients with malignant melanoma have early lesions, which are diagnosed at stage I [10]. The majority of Chinese patients with malignant melanoma are diagnosed at stage II or III [8]. Due to the low incidence of malignant melanoma in the Asian population and scarce large-scale clinical trials, the number of melanoma cases reported in Asia is limited. In order to better understand this highly aggressive and race-specific malignant tumor, more information on different races is needed. Southwest Hospital is a first-class hospital in Southwest China. Due to the high level of medical care in this hospital many patients undergo diagnostic tests and treatment. Therefore, the cases of malignant melanoma selected from this hospital comprehensively reflect the incidence of malignant melanoma in Southwest China. In this study, we selected 82 patients with malignant melanoma treated at Southwest Hospital between 2009 and 2014. The epidemiologica (...truncated)