In present time it is generally accepted that upper gastrointestinal tumors develop from premalignant lesions. The incidence of adenocarcinoma of the esophagus, like adenocarcinoma of the gastric cardia, is increasing rapidly. Surgical treatment of these kinds of cancer become determinative factors of patient survival. Notwithstanding the progresses in modern surgical therapy of gastroesophageal junction tumors treatment there are no successes in improving patient survival. This lack of effectiveness may be changed by treatment strategy which was based on the personal prognosis as well as developing new diagnostic tests with a focus on identification of the patients from high risk population at early stage of malignant transformation. p53 plays a crucial role in cellular proliferation and apoptosis and as the guardian of genomic integrity. The aim of this study is to analyze p53 expression in esophageal and gastric cardia cancers.

Immunohistochemical staining was performed on routinely processed paraffin primary tumour sections from 28 patients with cancer (5 esophageal squamous cell carcinoma, 23 adenocarcinoma of gastroesophageal junction (Siewert 1–2–3) who underwent curative surgery. Additionally we analyzed control group of patients with non-cancer lesion or normal tissue of upper digestive tract (13 patients). During the research p53 was evaluated according to 2 categories: intensity and diffusion. Immunohistochemical staining was performed using primary antibody – monoclonal p53 protein clone DO-7 (DakoCytomation).

For the purpose of the present study, gastric cardia tumours were retrospectively classified according to the Siewert classification based upon both the macroscopic appearance during the surgical procedure and the detailed pathological record. Complete resection was performed for all patients. No one of the patients received preoperative chemo and/ or radiotherapy. Survival rates were calculated according to the Kaplan–Meier method. Univariate and multivariate analysis were performed using the chi-square test, Fisher’s exact test, and the Cox proportional hazards model. The association between the antigen expression and pathological features was evaluated with the help of the Mann–Whitney U test for two independent samples.

Results. No statistically significant correlation between the expression of p53 and the parameters of the primary tumor was revealed. Nevertheless p53 expression was significantly higher in the cancer tissue (65% of patients) than in normal (69,23% of patients).

No significant difference in p53 expression between esophageal and gastric cardia cancer was observed. Patients with different type of gastric cardia cancers (according to Siewert classification) are similar according to the pattern of p53 expression. We did not reveal any association between p53 expression and median survival of esophageal and gastric cardia patients (р53 intensity р=0,354, р53 diffusion р=0,63). In the upper gastrointestinal tumors certain peculiarities in р53 expression exist p53 expression doesn’t indicate prognosis of this group of patients.

Conclusion. In conclusion our results show that p53 examination in biopsy specimens taken during endoscopies in patients with precancerous lesions may be helpful for early diagnosing of the upper digestive tract tumors.

Ключові слова: esophageal and gastric cardia cancer, р53, prognosis

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