AIM:To characterize the alteration and significance of p53and PCNA in cancer and adjacent tissues of concurrent cancersfrom the esophagus and gastric cardia in the same patient.METHODS:P53 and PCNA protein accumulation in 25patients with concurrent cancers from the esophagus andgastric cardia(CC,concurrent carcinomas of esophagealsquamous cell carcinoma and gastric cardia adenocarcinoma)were detected by immunohistochemical method(ABC).RESULTS:In CC patients,both esophageal squamous cellcarcinoma(SCC)and gastric cardia adenocarcinoma(GCA)tissues showed different positive immunostaining extent ofp53 and PCNA protein(P>0.05).The positive immunostainingrates for p53 and PCNA were 60%(15/25)and 92%(23/25),respectively in SCC;and 40%(10/25)and 88%(22/25),respectively in GCA.“Diffuse”immunostaining patternwas frequently observed in both p53 and PCNA.Highcoincidence rates for p53 and PCNA positive staining wereobserved in SCC and GCA from the same patients,andaccounted for 56% and 96%.In SCC patients,with thelesions progressed from normal esophageal epithelium(NOR)to basal cell hyperplasia(BCH)to dysplasia(DYS)tocarcinoma in situ(CIS)to SCC,the positive rates for p53were 27%,50%,50%,29% and 72%,and 55%,70%,75%,71% and 93% for PCNA,respectively.In GCA,withthe lesions progressed from normal gastric cardia epitheliumto DYS to CIS to GCA,the positive rates of p53 expressionwere 44%,27%,22% and 36% respectively,the differencewas not significant;the positive rates of PCNA proteinexpression were 67%,64%,67% and 86%,respectively.The x~2 test,Fisher’s Exact Test,ManteI-Haenszel x~2 Testand Kappa Test were used for the statistics.CONCLUSION:The high coincident alterations for P53 andPCNA in SCC and GCA from the same patient indicate thepossibility of similar molecular basis,which providesimportant molecular basis and etiological clue for similargeographic distribution and risk factors in SCC and GCA. AIM: To characterize the alteration and significance of p53 and PCNA in cancer and adjacent tissues of concurrent cancers from the esophagus and gastric cardia in the same patient. METHODS: P53 and PCNA protein accumulation in 25patients with concurrent cancers from the esophagus andgastric cardia (CC, concurrent carcinomas of esophageal squamous cell carcinoma and gastric cardia adenocarcinoma were detected by immunohistochemical method (ABC) .RESULTS: In CC patients, both esophageal squamous cellcarcinoma (SCC) and gastric cardia adenocarcinoma (GCA) tissues showed different positive immunostaining extent of p53 and PCNA protein P <0.05). The positive immunostaining for p53 and PCNA were 60% (15/25) and 92% (23/25), respectively in SCC; and 40% (10/25) and 88% (22/25) respectively in GCA. “Diffuse ” immunostaining pattern was frequently observed in both p53 and PCNA. Highcoincidence rates for p53 and PCNA positive staining wereobserved in SCC and GCA from the same patients, andaccounted for 56% and 96%. In SCC patients, with thelesions progressed from normal esophageal epithelium (NOR) to basal cell hyperplasia (BCH) to dysplasia (DYS) tocarcinoma in situ (CIS) to SCC, the positive rates for p53were 27%, 50%, 50%, 29% and 72%, and 55%, 70%, 75%, 71% and 93% for PCNA, respectively. In GCA, with the lesions progressed from normal gastric cardia epithelium to DYS to CIS to GCA, the positive rates of p53 expressionwere 44%, 27 %, 22% and 36% respectively, the difference was not significant; the positive rates of PCNA proteinexpression were 67%, 64%, 67% and 86%, respectively.The x ~ 2 test, Fisher’s Exact Test, ManteI- Haenszel x ~ 2 Test and Kappa Test were used for the statistics. CONCLUSION: The high coincident alterations for P53 and PCNA in SCC and GCA from the same patient indicate the same of similar molecular basis, which provides intravenous basis and etiological clue for similargeographic distribution and risk factors in SCC and GCA.