Alterations of p53 and PCNA in cancer and adjacent tissues from concurrent carcinomas of the esophagus and gastric cardia in the same patient in Linzhou, a high incidence area for esophageal cancer in northern China.

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 25 patients with concurrent cancers from the esophagus and gastric 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 cell carcinoma (SCC) and gastric cardia adenocarcinoma (GCA) tissues showed different positive immunostaining extent of p53 and PCNA protein (P>0.05). The positive immunostaining rates 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. High coincidence rates for p53 and PCNA positive staining were observed in SCC and GCA from the same patients, and accounted for 56 % and 96 %. In SCC patients, with the lesions progressed from normal esophageal epithelium (NOR) to basal cell hyperplasia (BCH) to dysplasia (DYS) to carcinoma in situ (CIS) to SCC, the positive rates for p53 were 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 expression were 44 %, 27 %, 22 % and 36 % respectively, the difference was not significant; the positive rates of PCNA protein expression were 67 %, 64 %, 67 % and 86 %, respectively. The chi(2) test, Fisher's Exact Test, Mantel-Haenszel chi(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 possibility of similar molecular basis, which provides important molecular basis and etiological clue for similar geographic distribution and risk factors in SCC and GCA.