Immunoexpression of p53 as an indicator of invasiveness in esophageal carcinoma:- a tertiary care hospital study from Punjab, India
Authors: Rahul Mannan, Mridu Manjari, Harleen Kaur, Tejinder Singh Bhasin, Sonam Sharma
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Esophageal carcinoma (EC) is an upcoming major health challenge with 4,07,000 deaths related to it reported globally in the year 2008 alone. Its risk factors apart from tobacco and alcohol vary according to various geographical areas which include ethnicity, dietary and other socio-economic factors. This can have a bearing on its various prognostic factors in which Immunohistochemistry (IHC) has emerged as a major tool for predicting the same.
p53 has proved to be a particular important molecule in development of many tumors including esophageal carcinoma as it has a role in both tumor immunity and cell cycle.
The present study was conducted in Punjabi population where tobacco usage is low because of the societal and religious taboos and where life style and developmental indicators are high in comparison to rest of India. The aim was to analyze epidemiologically the cases suffering from esophageal carcinoma, to study p53 expression in histologically proven cases of esophageal carcinoma and also to correlate p53 positive expression with the type and grade of the tumor along with other clinico-pathological parameters.
Material and Methods: The study was conducted on 50 cases of EC diagnosed in the Department of Pathology, Sri Guru Ram Das Institute of Medical Sciences and Research, Amritsar, Punjab, India. The 50 cases (either endoscopic biopsies or esophagectomy specimen) were independently verified for sub classification and histopathological grading. In all the cases patient’s complains, age, gender and other important clinical parameters were recorded. All the cases were taken up for IHC study for p53 expression.
The results obtained were tabulated and statistically analyzed. A p value less than 0.05 was considered statistically significant.
Result: In the present study, maximum cases (60%) were observed in the age group of 41-60 years where female patients outnumbered male patients in a ratio of (1.3:1). Lower segment (56%) was the most common segment involved. Histopathologically, most of the cases were of the squamous cell type (constituting 94% of the total cases) followed by adenocarcinoma with most of these cases graded as G2 (moderately differentiated). In 20 cases of esophagectomy specimen included in the present study; both lymph node metastasis and adventitial layer involvement (full thickness) was identified in 13 cases each. p53 expression was observed in 50% cases (percentage of positive cells varying from 5-89% with mild, moderate and strong staining intensity) with positivity seen in 48.9% cases of squamous cell carcinoma (ESCC) and 66.7% in adenocarcinoma (EAC). Of the cases included in the study; no significance between grading, lymph node status and p53 expression was elicited. However, correlation of p53 and adventitial involvement was noted and this finding was statistical significant.
Conclusion: The present study is the first such study done on North Indian Punjabi population. The finding of significant association of p53 expression with adventitial involvement (full thickness involvement) is an important prognostic factor to comment upon the invasiveness of the disease in an individualized manner.