The Comparative Study Of Esophageal Squamous Cell Carcinoma In Han, Kazak, Uygur, Hui And Mongolian Of China

1 BackgroundEsophageal cancer is the most common malignant tumor of digestive system.Its incidence is located in the eighth of all the cancer and Its mortality in the sixth.There were 456000 new cases in 2012 in worldwide and 400000 deaths.80% of cases occured in developing countries and regions.Esophageal cancer has higher morbidity and mortality in China.The number incidence of esophageal cancer was 478000 and the number death was 375000 in 2015.Its incidence rate located in third place and fourth of mortality rate.Epidemiological studies have found that esophageal cancer has regional differences and ethnic differences in China.But the main histological type of esophageal carcinoma is esophageal squamous cell carcinoma(ESCC)in China.To investigate the incidence of esophageal cancer risk factors,there was not close relationship between smoking or drinking and ESCC.With positive family history,nutrient deficiency,bad living habits and eating habits and unreasonable dietary structure is important risk factors of ESCC.In addition,gene polymorphism may be a risk factor of ESCC.The survival prognosis of patients with ESCC was closely related with onset of age,high or low area,sex,occupation,family history,tumor size,lymph node metastasis,and tumor molecular markers,and so on.And these factors were intertwined together to influence the survival.Recently,whole-genome sequencing(WGS)and whole-exome sequence(WES)has shed light on esophageal squamous carcinoma of different gene mutations and their corresponding carcinogenic signaling pathways in the body.WES about Chinese ESCC has been reported.Gao analysed 113 ESCC that came from Beijing area by WES.Zhang and Song reported WES of ESCC that came from Taihang Mountain and Guangdong province.Despite there were literatures to report differences between different ethnic groups on the incidence of esophageal cancer risk factors,genetic susceptibility,and clinical epidemiology and molecular,most of reports were on the same area.Firstly,our aim of study is to analyse the epidemiological characteristics of ESCC in Han,Kazak,Uygur,Hui and Mongolian and get factors which affect the prognosis of patients with ESCC.Secondly,123 cases of Han ESCC and 26 cases Kazak ESCC was analysed by WES.We have got different mutation genes in Han people with ESCC and Kazak people with ESCC.Then discuss mutation genes how to effect the survival of patients with ESCC.2 Materials and methods2.1 Clinical epidemiological features and factors affecting survival about Han,Kazak,Uygur,Hui and Mongolian patients with ESCC2.1.1 ObjectsThere were together 2113 patients with ESCC.The mean age was 58.5± 9.7(age range,31-87 years).Male: Female = 2.6:1.There were 1587 Han patients whose mean age was 58.5 ±9.7.Han male: female = 2.6:1.There were 221 Kazak patients whose mean age was 57.3± 9.7.Kazak male: female = 2.3:1.There were 136 Uighur patients whose mean age was 56.6±9.0.Uighur male: female = 2.2:1.There were 89 Hui patients whose mean age 63.2± 9.6.Hui male: female = 2.1:1.There were 80 Mongolian patients whose mean age is 59.6 ±9.5.Mongolian male: female = 9:1.2.1.2 MethodsThe main method was face to face epidemiological questionnaire.The complementary investigation methods were by telephone follow-up and inspection of the medical records.The contents included the basic data of patients,general physical examination and sick situation,living habits,tumor family full investigation.To verify and supplement clinical data and pathological information in hospital.The clinical pathological data included esophageal position of tumor,gross type,differentiation degree,surgical cut edge,and so on.The survival of patients with ESCC was followed up by telephone or face to face investigation.Using SPSS 21.0(SPSS,Inc.,Chicago IL,USA)statistical software to analyze the relevant datas.The average diagnostic age between Han,Kazak,Uighur,Hui and Mongolian patients was analysed by t test.The single factor survival of Han,Kazak,Uighur,Hui and Mongolian patients was analysed by Kaplan Meier and the Log-rank test.The multiple factors survival of Han,Kazak,Uighur,Hui and Mongolian patients were analysed by Cox proportion model of risk.2.2 Analysis of genome mutation spectrum in Chinese Han and Kazak patients with ESCC2.2.1 ObjectsThere was 123 Han patients(5.82%,123/2113)and 26 Kazak patients(1.23%,26/2113).All samples included primary lesion of ESCC and matched normal tissue adjacent to carcinoma tissues,which were confirmed by pathological diagnosis.All of the patients had detailed preoperative clinical history data.And there were not any anti-tumor treatment.2.2.2 Research methodsFirst of all,genomic DNA was extracted from carcinoma tissues and matching tissues.And quality and concentration of DNA was detected.Then DNA was sequenced by WES.We analysed biological information and tested target area capture sequencing.Finally,the dates were analysed by SPSS 21.0(SPSS,Inc.,Chicago,IL USA).Two sample mean was analysed by Student ’s t test.Count datas were analysed by Fisher’s exact test.The survival of Han or Kazak patients with ESCC were analysed by the Kaplan-Meier and Cox method.3 Results3.1 Clinical epidemiological features and factors affecting survival about Han,Kazak,Uygur,Hui and Mongolian patients with ESCC3.1.1 The clinical epidemiological characteristics of Han,Kazak,Uygur,Hui and Mongolian patients with ESCCHan,Hui and Mongolian patients rural areas > urban areas;Kazak and Uighur patients urban areas > rural areas.There were considerable number between Han and Mongolian patients in high and low incidence area of ESCC.The number of Kazak and Uighur in high incidence area of ESCC were significantly higher than low area.Most of the patients with ESCC of the five national had the normal weight.There were considerable numbers between Han and Kazak patients about smoking and non-smoking.There were lower smoking in Uygur and Hui patients and higher smoking in Mongolian patients.There were lower drinking in Han,Kazak,Uygur and Hui patients and higher drinking in Mongolian patients.HP positive rate in Han,Kazak,Uygur and Mongolian patients were lower.The HP positive of Hui patients was 57.1%.The best site of tumor was in the middle part of the esophagus in all national.And the general type was ulcer type in all national.The middle differentiation was priority in Han Kazak,Uygur and Mongolian patients.The low differentiation was the main differentiation of Hui patients.Positive lymph nodes metastasis rate of Han,Kazak,Uygur,Hui and Mongolian patients were 38.4%,42.2%,29.0%,42.2%and 40.6%,respectively.TNM Ⅱwere mainly period in all national.Five nationality patients were treated with surgery alone as the main way.3.1.2 Survival factors of Han,Kazak,Uygur,hui and Mongolian ESCC3.1.2.1 National differences affected survivalof patients with ESCC(P < 0.001).3.1.2.2 The prognosis of Han patients before 50 years old was significantly higher that of after the age of 50.And after 50 years of age,the prognosis of Han patients was worse and worse with the growth of the age.There was no obvious difference among ages in Kazak,Uighur,Hui and Mongolian patients.3.1.2.3 The survival of Han patients in rural areas was better than in urban within 10 years(P < 0.001).After 10 years,there was no significant difference between two areas.The survival of Kazak,Uighur,Hui and Mongolian patients in urban is significantly higher than that of in rural(P = 0.007).3.1.2.4 The survival of all ethnic patients in high-risk area were significantly higher than that of low-risk area.3.1.2.5 There were no difference among different BMI that effected the survival of all ethnic patients.3.1.2.6 The survival of Han patients with positive family history was superior to that of negative family history(P = 0.001).There was no obvious difference between positive family history and negative family history in Kazak,Uighur,Hui and Mongolian patients(P = 0.22).3.1.2.7 There were no obvious differences between smoking and no-smoking,or drinking and no-drinking in all ethnic patients about survival analysis.3.1.2.8 The survival of Han patients was no related with positive HP infection(P= 0.09).The prognosis of Kazak,Uighur,Hui and Mongolian patients patients with positive HP infection were poorer than that of negative HP infection(P =0.001).3.1.2.9 The survival of Han patients was no related with tumor position(P = 0.42).The survival of Kazak,Uighur,Hui and Mongolian patients whose tumor lied in middle chest was better than that of in upper and lower chest(P = 0.02).3.1.2.10 The survival of Han patients with narrow type was worst(P = 0.007).The survival of Kazak,Uighur,Hui and Mongolian patients was related with gross type of tumor(P = 0.21).3.1.2.11 The survival of Han patients was worse and worse decline of the differentiation degree(P = 0.001).The survival of Kazak,Uighur,Hui and Mongolian patients was no related with differentiation degree(P = 0.07).3.1.2.12 The survival of Han patients was no related with positive cut edge(P = 0.34).The survival of Kazak,Uighur,Hui and Mongolian patients was better than that of negative patients(P = 0.01).3.1.2.13 The survival of Han patients with lymph node metastasis positive was significantly lower than that of negative patients(P < 0.001).The survival of Kazak,Uighur,Hui and Mongolian patients was no related with lymph node metastasis(P = 0.37).3.1.2.14 The survival of Han patients in TNMⅠwas better than that of in TNMⅡ,TNM Ⅱ was better than TNM Ⅳ and TNM Ⅳ was better than TNM Ⅲ(P < 0.001).The survival of Kazak,Uighur,Hui and Mongolian patients was no related with TNM staging(P = 0.88).3.1.2.15 The survival of Han patients was no related with different surgical procedures(P = 0.52).The survival of Kazak,Uighur,Hui and Mongolian patients with left surgical procedures was better than that of right surgical procedures(P = 0.02).3.1.2.16 The survival of Han patients was no related with different treatments(P = 0.15).The survival of Kazak,Uighur,Hui and Mongolian patients with only surgery was best(P < 0.001).3.1.3 Independent factors affecting survivalDiagnostic age,high-risk or low-risk areas,the differentiation degree of ESCC and TNM staging were independent factors of survival in Han patients with ESCC.Diagnostic age and rural or urban areas were independent factors of survival in Kazak,Uighur,Hui and Mongolian patients with ESCC.3.2 Analysis of genome mutation spectrum in Chinese Han and Kazak patients with ESCC3.2.1 SNVs3.2.1.1 SNVs type and region(1)SNVs type and region of Han patients with ESCCThere were 166945 mutation events,including 158531 SNP,3831 Insertion and 4583 deletion.It included 17.89% SNP missense mutations,0.58%nonsense mutation,9.34%Frame_Shift_Ins,6.88%In_Frame_Ins,10.16% Frame_Shift_Del,7.15% In_Frame_Del.(2)SNVs type and region of Kazak patients with ESCCThere were 3967 mutation events,including 2959 SNP,505 Insertion and 503 Deletion.It included 40.49% SNP missense mutations,1.89%nonsense mutation,43.37%Frame_Shift_Ins,16.83%In_Frame_Ins,52.49% Frame_Shift_Del,10.14% In_Frame_Del.3.2.1.2 Mutant gene(1)Mutant gene of Han patients5 significant mutations were detected,which were TP53,FAM194 B,MSH3,ZNF750 and C19orf73.The mutation rates were 6.5%,6.5%,4.7% and 2.8%,respectively.(2)Mutant gene mutation of Kazak patients7 significant mutations were detected,which were TP53,PBRM1,SMAD4,SPDYE4,STATH,RAC1 and RAC2.The mutation rates were 1.3%,0.8%,0.8%,0.4%,0.4% and 0.4%,respectively.3.2.2 The survival of Han and Kazak patients was effected by the significant mutant genes3.2.2.1 Han patientsTP53,FAM194 B,MSH3,ZNF750 and C19orf73 were not the independent influencing factors of the Han patients with ESCC(P>0.05).3.2.2.2 Analysis of Kazak significantly mutated genes the survival of patients with ESCCTP53、PBRM1、RAC1、SMAD4、SPDYE4、STATH and RAC2 are not affecting the survival of Kazakh patients with ESCC(P > 0.05).4 Conclusions(1)There was difference among Han,Kazak,Uighur,Hui and Mongolian patients with ESCC in clinical epidemiological features.BMI and Ⅲ Ⅳ,history of smoking or drinking and HP infection positive number in Kazak,Uighur,Hui and Mongolian patients with ESCC was higher than that of Han patients.(2)The ethnic difference was an important factor that affects survival time of patients with ESCC.And the survival of Kazak and Uighur patients with ESCC were better than that of Han,Hui and Mongolian patients.(3)As the diagnosis age was later,the prognosis of patients with ESCC was worse.The elder patients who were diagnosed may be the high risk factors of prognosis.(4)The prognosis of patients was worse and worse with decline of differentiation degree.The lower differentiation degree may be a risk factor for patients with poor prognosis.(5)By comparative study on the survival of Han,Kazak,Uighur,Hui and Mongolian patients,there was important guiding significance to reveal the environmental and genetic factors that effected development and prognosis of ESCC.(6)The significant mutations in Han patients with ESCC were TP53,FAM194 B,MSH3,ZNF750 and C19orf73.(7)The significant mutations in Kazak patients with ESCC were TP53,PBRM1,RAC1,SMAD4,SPDYE4,STATH and RAC2.(8)TP53,FAM194 B,MSH3,znf750 and C19orf73 are not independent factors affecting the prognosis of Han patients with ESCC.P53、PBRM1、RAC1、SMAD4、SPDYE4、STATH and RAC2 are not affecting the survival of Kazakh patients with ESCC.