Ekspresi P53 Mutan dalam Menentukan Derajat Differensiasi dan Prognosa Adenokarsinoma Kolorektal di Laboratorium Patologi Anatomi Rsup Haji Adam Malik Medan

Abstract

Background : Cancer is important problem in public health worldwide especially in developed countries. About 10 millions new cases was diagnosed every year. Colorectal carcinoma is more common in man than woman. Despite significant advances in both surgical methodology and adjuvant therapy regimes, long-term survival for CRC patients remains in the range of 50-60%. Based on WHO, 90 % colorectal carcinoma was adenocarcinoma. Colorectal carcinoma is caused by a collection of various genetic changes and the most common cause is a loss of function of the p53 tumor suppressor gene. P53 tumor suppressor gene plays an important role in cell cycle and apoptosis. This gene encodes for a 53 Daphosphoprotein and is frequently targeted for inactivation in a wide range of tumours. It is the target of point mutations and small deletions and insertions that lead to total or partial abolition of protein function. Inactivation is believed to abolish the ability of p53 to maintain genomic integrity through regulation of various activities, including the control of cell cycle arrest, DNA repair and apoptosis.. Accumulation of p53 in tumor cells can be detected with a specific p53 antibody. Mutation on p53 gen and over ekspression of p53 is common incolorectal carcinoma tissue then p53 mutant and p53 wild type can be targeted by p53 specific antibody. P53 overexpression associated with colorectal carcinoma histologycal grade and tend more common in colorectal carcinoma with high proliferation activity. Objective : To assess p53 mutan expression in determining differentiation grade and prognose adenocarcinoma colorectal and the prognose of adenocarcinoma colorectal at Anatomic Pathology laboratory of RSUP Haji Adam Malik Medan. Methods :The study designwasobservationaldesignwithcross sectionalapproach. All variables were immunohistochemically stained with p53 mutant. The variables were measured only oncean datone moment. The samples usedin this study were the sample preparation of paraffin blocks from 59 colorectal carcinoma tissues which diagnosed patologically according inclusion criteria. All variables were immunohistochemically stained with p53 mutant. Results :Distribution ofpatientsby age group mostly aged over 60 years which is 24 cases (40.68%). Distribution ofpatients by sex mostly male which is 36 cases (61.02%). 36 cases (61,02%) were located on colon. The majority, 27 cases (45,76%) were diagnosed aswell differentiated adenocarcinoma. Colorectal carcinoma samples based on p53 mutant expression were score+1(weak) were 35 cases (59,32%). Calculation ofchi-square with 2x2 crosstabtable, p value=0.427(p value>0.05).

Conclusion. No difference between p53 mutant expression with histopathological grade incolorectal adenocarcinoma.

Latar Belakang. Kanker merupakan problem penting bagi kesehatan masyarakat diseluruh dunia terutama pada negara-negara berkembang. Sekitar sepuluh juta kasus baru didiagnosa setiap tahunnya. Angka kejadian adenokarsinoma kolon ditemukan lebih banyak pada laki-laki daripada perempuan. Berdasarkan World Health Organization 90% kasuskarsinoma kolorektal tipe adenokarsinoma. Penyebabnya hilang fungsi dari tumor supresor gen p53. Mutasi, delesi kecil dan insersi dapat menyebabkan kerusakan fungsi protein secara total maupun parsial. Over ekspresi p53 mutan berhubungan dengan grading histologi dari karsinoma kolorektal dan cenderung lebih sering pada karsinoma kolorektal yang aktivitas proliferasinya tinggi. Tujuan. Untuk mengetahui ekspresi p53 mutan dalam menentukan derajat differensiasi dan prognosa adenokarsinoma kolorektal di Laboratorium Patologi Anatomi RSUP Haji Adam Malik Medan Metode. Penelitian ini menggunakan rancangan observasional dengan melakukan pendekatan cross sectional. Sampel penelitan ini adalah sediaan blok parafin dari 59 jaringan karsinoma korektal yang didiagnosa sesuai dengan kriteria inklusi. Semua variabel diwarnai dengan immunohistokimia p53 mutan. Hasil. Distribusi terbanyak penderita karsinoma kolorektal berdasarkan; kelompok usia 60 tahun sebanyak 24 kasus (40.68%), jeniskelamin; laki-laki sebanyak 36 kasus (61.02%), lokasi jaringan; colon sebanyak 36 kasus (61.02%), grading adenokarsinoma ; well differentiated adenocarcinoma sebanyak 27 kasus (45.76%) dan berdasarkan tampilan p53 mutan yang terbanyak adalah skor +1 (lemah): 35 kasus (59,32%). Perhitungan fisher exact dengan tabel crosstab 2x2 bahwa p value= 0,427 (p value> 0,05). Kesimpulan. Tidak ada perbedaan ekspresi p53 mutan dengan grading histopatologi pada adenokarsinoma kolorektal. Kata kunci: adenokarsinoma, karsinoma kolorektal, immunohistokimia p53mutan