Clinical Features And Prognosis Of Asian American Patients With Cutaneous Melanoma

[Background]Cutaneous Melanoma(CM)is a malignant tumor that originates from melanocytes and occurs in the skin.In recent years,there has been a marked increase in the incidence of CM worldwide and the resulting burden of disease is increasing.Existing studies have shown that CM has significant geographical and ethnic differences in epidemiological characteristics,clinical presentation,pathological features and prognosis.In Asian countries,including China and Pacific Island countries,the incidence of CM is relatively low and research are relatively inadequate,especially in the absence of large sample data studies and unbiased estimation of clinical characteristics and prognosis of CM.[Objectives]This study designed an observational study of large sample of Asian or Pacific Islander(API)patients,while Non-Hispanic White(NHW)patients as positive controls,to examine the differences between API and NHW in terms of clinical manifestation and pathological classification,and to evaluate the impact of racial differences on the prognosis of CM.Aims to further enhance people's understanding of racial differences in CM and provide reference for the formulation and improvement of CM disease prevention strategies in China.[Methods]The data of patients is collected from Surveillance,Epidemiology and End Results(SEER)database with Site Recode ICD-O-3/WHO 2008 as Melanoma of the Skin,Race and origin as NHW and API,which were registered in California for the period 2004-2016.And the final cohorts were constructed by screening cases according to inclusion and exclusion criteria.Variables included in the analysis are Race,S.ex,Age at diagnosis,Year of diagnosis,Primary Site,Surgery of primary Site,Histologic Type ICD-O-3,Derived AJCC Stage7th and Survival information etc..A subgroup analysis was used to preliminarily describe the differences between API and NHW in terms of demographic characteristics,clinical manifestation,and pathological classification.Using survival analysis with CM-specific death as the outcome event and survival time as the outcome variable,univariate Kaplan-Meier analysis,univariate COX regression analysis and multivariate COX regression analysis were performed to preliminarily assess the impact of racial differences on the prognosis of CM.The propensity score matching(PSM)method was used to construct a matched cohort between API and NHW.to evaluate the effect of racial differences on the prognosis of the two cohorts under the premise that the baseline information was relatively balanced.The difference between two groups was described by the Chi-square test before and after matching,and P<0.05 was considered statistically significant.[Results]?A total of 82,660 cases meeting the criteria are included for subgroup analysis,including 770 cases in the API group and 81,890 cases in the NHW group.The analysis found the there were differences between API and NHW in terms of Sex,Age at diagnosis,Primary Site,Surgery of primary Site,Histologic Type ICD-O-3,Derived AJCC Stage7th,etc.(P<0.05).?Removal of patients with stage 0 by AJCC 7th Staging int the original cohort resulted in the inclusion of 48,874 cases(570 cases in the API group and 48,304 in the NHW group)for survival analysis.The survival analysis was performed by KM analysis,which found that there was a significant difference in survival between patients in the API group and the NHW group,log-rank test with P<0.001.Univariate COX regression analysis showed that the hazard ratio of death was 2.778 and the 95%confidence interval(CI)was 2.330-3.31 1.?Multivariate COX regression analysis found that Race,Sex,Age at diagnosis,Primary Site,Surgery of primary Site,Histologic Type ICD-O-3,Derived AJCC Stage7th are independent variables for prognosis.The risk factors for prognosis are API,Male,older Age at diagnosis,Skin of scalp and head,Skin of trunk,Nodular melanoma(NM),Acral Lentiginous melanoma(ALM),later AJCC staging.The protective factors for prognosis are NHW,Female,Skin of upper limb and shoulder,Skin of face,Superficial spreading melanoma(SSM),Lentigo maligna melanoma(LMM),all type Surgery of primary Site.?PSM is performed on case information from the API and NHW groups to derived the matched cohort(570 cases in the API group and 1,676 in the NHW group).KM analysis of the matched cohort revealed that there is still a difference in prognosis between the two groups,with log-rank test P=0.032.Univariate COX regression analysis showed that patients in the API group had HR=1.314 and 95%CI(1.069-1.615)compared to the NHW group.With AJCC staging as a stratified variable,KM analysis showed that the difference in survival between patients in the API group and the NHW group is mainly in patients in stages ? and ? with P=0.020 and 0.042.[Conclusions]There are significant differences in epidemiological characteristics and clinicopathological features between API and NHW patients:API patients are relatively younger at diagnosis but later at AJCC staging;Primary lesions in API patients are more likely to occur in the "skin of lower limb and hip",as opposed to the NHW "skin of trunk";and although ALM is more common in API patients,SSM is still the pathological type in known types with the largest proportion of API patients.Even after balancing the effects of these differences on prognosis,API patients had a worse prognosis than NHW patients,and the difference was predominantly between stage ? and stage ? patients.