Korelasi Ekspresi Reseptor Vitamin D (VDR) dengan Derajat Diferensiasi dan Stadium Adenokarsinoma Kolorektal

Abstract

Keganasan terbanyak ketiga di dunia pada organ kolorektal adalah karsinoma yang berasal dari lapisan epitel mukosa. Modalitas yang digunakan untuk terapi karsinoma kolorektal stadium lanjut selain operasi adalah kemoterapi dan saat ini dikembangkan terapi target sebagai alternatif terapi, yaitu metabolit aktif vitamin D, calcitriol. Calcitriol bekerja sinergis dengan agen kemoterapi yang aktivitasnya dimediasi oleh vitamin D reseptor (VDR). Penelitian ini bertujuan mengetahui korelasi imunoekspresi VDR dengan stadium dan derajat diferensiasi (grading) pada adenokarsinoma kolorektal. Menggunakan 35 blok parafin adenokarsinoma kolorektal yang diambil dari kolektomi, di Departemen Patologi Anatomi Rumah Sakit Dr. Hasan Sadikin Bandung periode 1 Januari 2009–30 Juni 2014, terbagi dalam 3 kelompok stadium (I, II, dan III) dan 3 kelompok derajat diferensiasi (well, moderately, dan poorly differentiated). Imunohistokimia dilakukan pada sampel untuk melihat ekspresi VDR pada massa tumor menggunakan antibodiprimer VDR. Data dianalisis menggunakan uji statistika korelasi Rank Spearman. Terdapat korelasi imunoekspresi VDR dengan stadium (p=0,045; R=-0,341) dan derajat diferensiasi (p=0,000; R=0,558). Pada penelitian ini VDR berperan dalam menentukan stadium dan derajat diferensiasi adenokarsinoma kolorektal. Hal ini dapat dijadikan pertimbangan dalam pemberian calcitriol sebagai bagian dari terapi target pada adenokarsinoma kolorektal dan acuan untuk penelitian selanjutnya dalam perkembangan terapi target. [MKB. 2016;48(2):123–8]

Kata kunci: Adenokarsinoma kolorektal, derajat diferensiasi, stadium, imunoekspresi VDR

Correlation of Vitamin D Receptor (VDR) Expression with Differentiation Staging and Grading in Colorectal Adenocarcinoma

Colorectal carcinoma (CRC) is a malignancy from mucosal epithelium of the colon/rectum. The treatment modalities used for advance stage colorectal carcinoma therapy is chemotherapy, in addition to surgery. Targeted therapy is currently being developed as an alternative therapy. One of the agents used in this therapy is calcitriol. Calcitriol is an active metabolite of vitamin D. Calcitriol works synergistically with chemotherapeutic agents and its activity is mediated by the vitamin D receptor (VDR). VDR plays a role in the inhibition of tumor progression via induction of cellular differentiation and proliferation inhibition. In this study, imunoexpression of vitamin D receptor was examined in conjunction with the staging and degree of differentiation (grading) of colorectal adenocarcinoma. The study objects include 35 colorectal adenocarcinoma paraffin blocks created from colectomy which were collected at the Department of Patology Anatomic of Dr. Hasan Sadikin General Hospital Bandung from January 2009–June 2014. The blocks were divided into three groups of staging (I, II, and III) and  three groups of grading: well, moderately, and poorly differentiated. Immunostaining was used to evaluate the VDR immunoexspression by histo-score. The data were tested using rank spearman test. There was a weak negative correlation between VDR imunoexpression and staging(p=0.045, R=-0.341), and a moderate positive correlation between VDR imunoexpression and grading (p=0.000, R=0.558). It is concluded that a significant correlation of VDR imunoexpression with staging and grading of colorectal adenocarcinoma is found and this finding can be used as a reference for further studies in the development of targeted therapies. [MKB. 2016;48(2):123–8]

Key words: Adenocarcinoma colorectal, grading, staging, VDR imunoexpression