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 Table of Contents  
ORIGINAL ARTICLE
Year : 2020  |  Volume : 9  |  Issue : 5  |  Page : 182-185

Bcl-2 expression in colorectal carcinoma and its correlation with clinicopathological parameters


Department of Pathology, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India

Date of Submission04-Oct-2017
Date of Decision18-Jul-2017
Date of Acceptance21-Jul-2020
Date of Web Publication12-Oct-2020

Correspondence Address:
Kavita Mardi
Set No 14, Type VI Quarters, IAS Colony, Meheli, Shimla, Himachal Pradesh
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ccij.ccij_51_17

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  Abstract 


Background: Bcl-2 gene is a 26-kD protein that blocks apoptosis and inhibits programmed cell death. Its mutation is frequently detected genetic alteration, in human cancers. Its expression can easily be detected by immunohistochemistry (IHC). Objective: The objective was to estimate the frequency of Bcl-2 expression in colorectal carcinoma and its correlation with clinicopathologic parameters. Materials and Methods: The overexpression of Bcl-2 was studied in 112 paraffin-preserved colorectal carcinoma samples using E-17 clone antibody; Biogenex. The number of cells stained was scored semiquantitatively as none (no immunoreactive cells detectable), weak (1+, <5%), moderate (2++, 5%–50%), and intense (3+++, >50%). All tumors showing Bcl-2 immunoreactivity (at least +) were considered positive. The correlation between Bcl-2 protein expression and clinicopathological parameters was evaluated using Chi-square analysis. Results: Bcl-2 staining was positive in 45 of 112 cases. Of these, 15 cases were weak positive (score 1), 17 cases were moderately positive (score 2), and 13 cases were intensely positive (score 3) for Bcl-2 protein expression. Sixty-seven cases were negative for Bcl-2 staining (score 0). There was statistically significant correlation between Bcl-2 staining and sex (49% of females expressed Bcl-2 in tumors; P = −0.04), pathological type (mucinous vs. nonmucinous; P = −0.02), and tumor stage (P = −0.04). There was no significant correlation between Bcl-2 staining and age (P = −0.38), site of tumor (left colon vs. right colon; P = −0.13), pathological differentiation (P = −0.73), and between Bcl-2 scoring and tumor differentiation (P = −0.91). Conclusion: Bcl-2 protein seems to play an important role in the carcinogenesis of colorectal cancer. Considering the acceptable reliability and feasibility of IHC method for the detection of Bcl-2 immunoreactivity, this technique may be expected to serve as an important diagnostic and prognostic marker in colorectal carcinoma.

Keywords: Bcl-2 gene, colorectal carcinoma, immunohistochemistry, protein expression


How to cite this article:
Bhardwaj M, Mardi K, Kaushal V, Sharma M, Rao M. Bcl-2 expression in colorectal carcinoma and its correlation with clinicopathological parameters. Clin Cancer Investig J 2020;9:182-5

How to cite this URL:
Bhardwaj M, Mardi K, Kaushal V, Sharma M, Rao M. Bcl-2 expression in colorectal carcinoma and its correlation with clinicopathological parameters. Clin Cancer Investig J [serial online] 2020 [cited 2020 Dec 2];9:182-5. Available from: https://www.ccij-online.org/text.asp?2020/9/5/182/298000




  Introduction Top


Colorectal carcinoma is the third most common cancer in men (663,000 cases, 10.0% of the total) and the second in women (571,000 cases, 9.4% of the total) worldwide.[1] Almost 60% of cases are encountered in developed countries.[2]

The etiology of colorectal cancer is complex, involving interplay of environmental and genetic factors.[3] The development of malignant colorectal carcinoma is a result of multistep changes including genetic factors, mutations, and epigenetic changes. These mutations occur in many tumor suppressor genes (APC, DCC, and TP53 genes) and proto-oncogenes (K-ras and C-myc gene) which result in inactivation of tumor suppressor genes and DNA mismatch of repair genes or activation of oncogenes.[4],[5],[6]

The Bcl-2 gene belongs to Bcl-2 family of proteins, which is a known gatekeeper to the apoptotic response.[7] Bcl-2 gene is a 26-kD protein that blocks apoptosis and thus inhibits programmed cell death.[8],[9],[10],[11],[12] Mutation in this gene is a frequently detected genetic alteration in human cancers with apoptosis regulation, playing a key role in this process.[13],[14],[15] The biomolecular aspects of colorectal cancer have raised great interest about Bcl-2 gene function.[16],[17]

In this study, we described the demographic characteristics of colorectal carcinoma cases diagnosed in Indira Gandhi Medical College (IGMC), Shimla, from April 2014 to April 2016. We studied the pattern of the Bcl-2 protein expression in different histopathological types of colorectal carcinoma and correlated it with clinicopathological parameters. We also studied its utility as a prognostic marker.


  Materials and Methods Top


The biopsy-proved colorectal carcinoma cases that were diagnosed and treated from April 2014 to 2016 in IGMC, Shimla, were selected for study. The secondary data of these patients including age, sex, family history, past history, histological type, grading of tumor, and stage of disease were obtained. The specimens were grossed and the sections were fixed in 10% formalin and paraffin embedded. Consecutive 4 μm sections were cut from the paraffin blocks. These sections were evaluated microscopically to select blocks without necrotic and hemorrhagic areas. Histopathological diagnosis was established on routine hematoxylin and eosin staining of the sections. Immunohistochemistry (IHC) for Bcl-2 was performed out on the BioGenex Xmatrix fully automated front-end processing system using monoclonal antibody against Bcl-2 protein (E-17 clonal antibody; Biogenex).

Two observers evaluated the immunoreactivity of sections for Bcl-2 semiquantitatively under ×40 magnification and as per the percentage of positive tumor nuclei, scored them as follows:

  • None (no immunoreactive cells detectable)
  • Weak (1+, <5%)
  • Moderate (2++, 5%–50%)
  • Intense (3+++, >50%).


All tumors showing Bcl-2 immunoreactivity (at least +) were considered positive. The observers were kept blind about the report of each other. After the initial evaluation of the results, cases with major discordance in reports were rechecked by both the observers, and after reaching an agreement, the report was submitted. The Bcl-2 scoring was correlated with clinicopathological parameters. The frequency of Bcl-2-positive tumors with each variable was analyzed using χ2; P < 0.05 was considered statistically significant.


  Results Top


Out of total of 112 cases of colorectal cancer, 61 (54%) patients were male and 51 (46%) were female. The mean age of patients was 55 years (range: 26–80 years). The tumor was located in the right colon in 48 (43%) cases, left colon in 57 (51%) cases, and was bilateral in 7 cases. Among 112 cases, 75 (67%) tumors were well-differentiated adenocarcinomas, 33 (29%) cases were moderately differentiated, and four cases were poorly differentiated adenocarcinomas. Among these, 31 (28%) cases were mucinous and 81 (72%) cases were nonmucinous. Lymphovascular invasion was detected in 20 (18%) cases and lymph nodes were involved in 42 (38%) cases. The stage was Duke A in 15 (13%), B in 54 (48%), C in 30 (27%), and D in 13 (12%) cases [Table 1].
Table 1: Clinicopathological correlation with Bcl-2 expression (n=112)

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Bcl-2 staining was positive in 40% (45 out of 112) of the cases. Of these, 15 cases were weakly positive (score 1) [Figure 1], 17 cases were moderately positive (score 2) [Figure 2], and 13 cases were intensely positive (score 3) [Figure 3] for Bcl-2 protein expression. Sixty-seven cases were negative for Bcl-2 staining (score 0). The relationship between Bcl-2 protein expression and several clinicopathological variables is summarized in [Table 1]. In our study, 39% of the patients below 60 years of age and 42% of the patients above 60 years of age showed Bcl-2 expression. Bcl-2 positivity was 33% in males and 49% in females. Left-sided tumors showed Bcl-2 expression in 34% of the cases and right side tumors showed it in 45% of the cases. Well-differentiated adenocarcinoma showed Bcl-2 positivity in 40% of the cases, moderately differentiated adenocarcinoma in 42% of the cases, and poorly differentiated adenocarcinoma in 25% of the cases. In pathological type, 26% of mucinous type and 46% of nonmucinous type showed Bcl-2 expression. In tumor stage, Bcl-2 positivity was 67% in Duke Stage A, 54% in Stage B, 33% in Stage C, and 30% in Stage D.
Figure 1: Score 1 weak (1+, <5%), Bcl-2 expression in colorectal carcinoma (IHC, ×400)

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Figure 2: Score 2 moderate (2++, 5%–50%), Bcl-2 expression in colorectal carcinoma (IHC, ×40)

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Figure 3: Score 3 intense (3+++, >50%), Bcl-2 expression in colorectal carcinoma (IHC, ×40)

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  Discussion Top


The Bcl-2 oncogene is a known inhibitor of apoptosis which may allow the accumulation and propagation of cells containing genetic mutation.[18] It is closely related to carcinogenesis in most malignant diseases. In the present study, Bcl-2 expression in colorectal carcinomas was found using IHC and was correlated with clinicopathological parameters to assess the utility of Bcl-2 expression in the diagnosis and prognosis of colorectal carcinoma.

In our study, age of the patients ranged between 26 and 80 years, which was comparable to study done by Sinicrope et al.[19] and Ghavam-Nasiri et al.[20]. The male-to-female ratio was 1:1, which was comparable to the study done by Ofner et al.,[21] Ghavam-Nasiri et al.,[20] and Sinicrope et al.[19] (1:1).

Among the 112 cases in our study, 45 (40%) cases were Bcl-2 positive, which was comparable with Bcl-2 positivity in the studies by Ofner et al. (45%),[21] Watson et al. (45%),[22] and Kaklamanis et al. (33%).[23] In this study, 39% of the patients who were below 60 years of age and 42% of the patients above 60 years of age expressed Bcl-2 immunoreactivity, which was similar to the study done by Manne et al.[24] Our study revealed Bcl-2 immunoreactivity in 33% of all male patients and 49% of all female patients. The results were comparable for males in the study done by Kaklamanis et al.[23]) and were comparable for females in studies done by Zhao et al.[18] and Manne et al.[24] Statistically significant correlation was seen between Bcl-2 positivity and sex of the patient (P = −0.04), which was not seen in any of the previous studies done.

Out of 75 (67%) of well-differentiated carcinoma, 30 (40%) revealed Bcl-2 positivity. Similar finding was noted by Kaklamanis et al.[23] in 36% of well-differentiated carcinoma. Nonmucinous tumors were more (81, 72%) than mucinous (31, 28%) tumors in our study. Comparable observations were made by Das et al.[25] and Ghavam-Nasiri et al.,[20] where the percentage of nonmucinous tumors was 72% and 78%, respectively. Bcl-2 was positive in 46% of nonmucinous adenocarcinomas in our study. There was a statistically significant correlation between Bcl-2 staining and pathological type (mucinous vs. nonmucinous; P = −0.02). However, no other previous studies revealed such correlation.

In our study, Bcl-2 positivity decreased with tumor stage (P = −0.04) and was comparable to studies done by Zhao et al.[18] There was no significant correlation between Bcl-2 staining and age (P = −0.38). This result was similar to that seen in studies done by Al-Temimi SMA etal.,[6] Goussia et al.,[26] Zhao et al.,[18] and Manne et al.[24] The site of tumor (left colon vs. right colon; P = −0.13) and pathological differentiation (P = −0.73) showed no correlation with Bcl-2 positivity.


  Conclusion Top


Bcl-2 protein seems to play an important role in the carcinogenesis of colorectal cancer and its expression decreased with increasing Duke stage, and there was a significant correlation of Bcl-2 positivity with sex and pathological type (mucinous versus nonmucinous). Considering the reliability and feasibility of IHC method for the detection of Bcl-2 immunoreactivity, this technique may be expected to serve as an important prognostic marker in colorectal carcinoma. However, more studies are required to establish the utility of Bcl-2 as a reliable prognostic marker in colorectal carcinomas.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
Society AC. Global Cancer Facts and Figures 3rd Edition. American Cancer Society; 2015. Available from: http://www.ncbi.nlm.nih.gov/pubmed/22019360. [Last accessed on 2020 Aug 28].  Back to cited text no. 1
    
2.
Consensus Document for Management of Colorectal Cancer; 2014. Available from: http://www.icmr.nic.in/guide/cancer/colorectal/colorectal Cancer.pdf. [Last accessed on 2020 Aug 28].  Back to cited text no. 2
    
3.
Leslie A, Pratt NR, Gillespie K, Sales M, Kernohan NM, Smith G, et al. Mutations of APC, K-ras, and p53 are associated with specific chromosomal aberrations in colorectal adenocarcinomas. Cancer Res 2003;63:4656-61.  Back to cited text no. 3
    
4.
Zekri J, Al-Shehri A, Mahrous M, Al-Rehaily S, Darwish T, Bassi S, et al. Mutations in codons 12 and 13 of K-ras exon 2 in colorectal tumors of Saudi Arabian patients: frequency, clincopathological associations, and clinical outcomes. Genet Mol Res 2017;16:1-11.  Back to cited text no. 4
    
5.
Pazour P, Coia L, Hoskins W, Wagman L. Cancer management: A multidisciplinary approach. 4th ed. NY: PRR Melville; 2000. p. 273.  Back to cited text no. 5
    
6.
Al-Temimi SM. Correlation between BCL2 protein expression and clinicopathological parameters of colorectal carcinoma. Kufa Med J 2011;14:206-13.  Back to cited text no. 6
    
7.
Hata AN, Niederst MJ, Archibald HL, Gomez-Caraballo M, Siddiqui FM, Mulvey HE, et al. Tumor cells can follow distinct evolutionary paths to become resistant to epidermal growth factor receptor inhibition. Nat Med 2016;22:262-9.  Back to cited text no. 7
    
8.
Hockenbery DM, Nunez G, Milliman C, Schreiber RD, Korsmeyer SJ. Bcl-2 is an inner mitochondrial membrane protein that blocks programmed cell death. Nature 1990;348:334-6.  Back to cited text no. 8
    
9.
Korsmeyer SJ. Bcl-2 initiates a new category of oncogenes: Regulators of cell death. Blood 1992;80:879-86.  Back to cited text no. 9
    
10.
Vaux DL. Toward an understanding of the molecular mechanisms of physiological cell death. Proc Natl Acad Sci USA 1993;90:786-9.  Back to cited text no. 10
    
11.
Reed JC. Bcl-2 and the regulation of programmed cell death. J Cell Biol 1994;124:1-6.  Back to cited text no. 11
    
12.
Valentini AM, Caruso ML, Armentano R, Pirrelli M, Rizzi E, Lapenna F, et al. Programmed cell death in colorectal carcinogenesis. Anticancer Res 1999;19:3019-24.  Back to cited text no. 12
    
13.
Katsumata K, Sumi T, Tomioka H, Aoki T, Koyanagi Y. Induction of apoptosis by p53, bax, bcl-2, and p21 expressed in colorectal cancer. Int J Clin Oncol 2003;8:352-6.  Back to cited text no. 13
    
14.
Tanner EA, Blute TA, Brachmann CB, McCall K. Bcl-2 proteins and autophagy regulate mitochondrial dynamics during programmed cell death in the Drosophila ovary. Development 2011;138:327-38.  Back to cited text no. 14
    
15.
Laulier C, Lopez BS. The secret life of Bcl-2: Apoptosis-independent inhibition of DNA repair by Bcl-2 family members. Mutat Res 2012;751:247-57.  Back to cited text no. 15
    
16.
Koehler BC, Scherr AL, Lorenz S, Urbanik T, Kautz N, Elssner C, et al. Beyond cell death-antiapoptotic Bcl-2 proteins regulate migration and invasion of colorectal cancer cells in vitro. PLoS One 2013;8:e76446.  Back to cited text no. 16
    
17.
Han HS, Park YM, Hwang TS. Differential expression of Bcl-2, Bcl-XL and p53 in colorectal cancer. J Gastroenterol Hepatol 2006;21:1108-14.  Back to cited text no. 17
    
18.
Zhao DP, Ding XW, Peng JP, Zheng YX, Zhang SZ. Prognostic significance of bcl-2 and p53 expression in colorectal carcinoma. J Zhejiang Univ Sci B 2005;6:1163-9.  Back to cited text no. 18
    
19.
Sinicrope FA, Ruan SB, Cleary KR, Stephens LC, Lee JJ, Levin B. Bcl-2 and p53 oncoprotein expression during colorectal tumorigenesis. Cancer Res 1995;55:237-41.  Back to cited text no. 19
    
20.
Ghavam-Nasiri MR, Rezaei E, Ghafarzadegan K, Seilanian-Toosi M, Malekifard H. Expression of p53 in colorectal carcinoma: Correlation with clinicopathologic features. Arch Iran Med 2007;10:38-42.  Back to cited text no. 20
    
21.
Ofner D, Riehemann K, Maier H, Riedmann B, Nehoda H, Tötsch M, et al. Immunohistochemically detectable bcl-2 expression in colorectal carcinoma: Correlation with tumour stage and patient survival. Br J Cancer 1995;72:981-5.  Back to cited text no. 21
    
22.
Watson NF, Zahra M, Dunkan S, Ian S, Ian OE, John HS, et al. Evidence that the p53 negative/Bcl-2 positive phenotype is an independent indicator of good prognosis in colorectal cancer: A tissue microarray study of 460 patients. Br Med J (Clin Res Ed) 2005;3:1477-7819.  Back to cited text no. 22
    
23.
Kaklamanis L, Savage A, Mortensen N, Tsiotos P, Doussis-Anagnostopoulou I, Biddolph S, et al. Early expression of bcl-2 protein in the adenoma-carcinoma sequence of colorectal neoplasia. J Pathol 1996;179:10-4.  Back to cited text no. 23
    
24.
Manne U, Myers RB, Moron C, Poczatek RB, Dillard S, Weiss H, et al. Prognostic significance of Bcl-2 expression and p53 nuclear accumulation in colorectal adenocarcinoma. Int J Cancer 1997;74:346-58.  Back to cited text no. 24
    
25.
Das P, Vaiphei K, Jain D, Wig JD. p53 and mdm2 expression in colorectal carcinoma: A correlative analysis with clinical staging and histological parameters. Int J Surg Pathol 2007;15:335-45.  Back to cited text no. 25
    
26.
Goussia AC, Ioachim E, Agnantis NJ, Mahera M, Tsianos EV. Bcl-2 expression in colorectal tumours. Correlation with p53, mdm-2, Rb proteins and proliferation indices. Histol Histopathol 2000;15:667-72.  Back to cited text no. 26
    


    Figures

  [Figure 1], [Figure 2], [Figure 3]
 
 
    Tables

  [Table 1]



 

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