Immunohistochemical Expression of K-Ras and Bcl-2 Protein
Tumor Markers in Colorectal Adenocarcinoma among
Sudanese Patients

Tagwa A. Mustafa, Ahmed H. Mohammed, Esam M. Abdul Raheem.
Immunohistochemical Expression of K-Ras and Bcl-2 Protein Tumor Markers in Colorectal
Adenocarcinoma among Sudanese Patients. African Journal of Medical Sciences, 2018, 3 (11)
ajmsc.inf

Abstract 
Background: Colorectal cancer (CRC) is the third most common malignant neoplasm in both
men and women with an estimated 96,830 cases of colon cancer and 50,310 deaths from colon
cancer predicted for 2014. Colorectal cancer affects the inner wall of the colon and the rectum
located within 12 cm or less from the anal verge. CRC is characterized by late clinical
manifestation and relatively rapid progression of the disease, both features that are primarily
responsible for increased morbidity and mortality in patients suffering from this disease. There is
new evidence that epigenetic slicing of genes may be an early event in the adenoma carcinoma
sequence. If CRC is diagnosed early enough, it can be considered to be preventable. This makes
it critical that inexpensive, highly sensitive, specific and non-invasive biomarkers be developed.

Objective: 
To detect the immunohistochemical expression of K-Ras and Bcl-2 protein tumor
markers in colorectal adenocarcinoma among Sudanese patients.

Materials and methods: 
This is a retrospective, analytical, case control study conducted at
Ibn Sina Teaching Hospital and Omdurman Teaching Hospital (Khartoum State) during the
period from April 2013 to December 2016. Paraffin embedded tissue specimens of 75 colorectal
adenocarcinoma patients were investigated for K-ras and Bcl- 2 protein expression by
immunohistochemical (IHC) technique using 2-step plus Poly-HRP Anti-Rabbit/Mouse IgG
Detection System. Staining patterns were subjectively assessed and correlated with clinicopathological features. 
The results were statistically evaluated using the Chi-square test,
 frequencies, and cross-tabling test.

Results: 
Among the 75 cases subjected to K-ras immuno-staining, 48 (64%) cases were positive
and for Bcl 2 protein 12% of cases were positive. Also the study found that there was significant
relation between type of tumor (metastasized and non-metastasized ) in colorectal
adenocarcinoma with K- ras (p = 0.034); and insignificant with Bcl 2 (p = 0.296). Also for
positive K-ras cases, 73% cases (37%) positive non metastasize malignant tumor and
metastasize one . The distribution of gender in the study population revealed that 43 cases
(57.3%) were males and 32 cases (42.7%) were females. There was no association between
gender and K-ras or Bcl 2 expression (p = 0.789). The distribution of age groups was significant