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ORIGINAL ARTICLE
Year : 2021  |  Volume : 24  |  Issue : 11  |  Page : 1737-1741

Comparison of histopathological findings of the colon adenomas and adenocarcinomas with cyclin D1 and Ki-67 expression


1 Department of Pathology, Gaziantep Dr. Ersin Arslan Education and Research Hospital, Gaziantep, Turkey
2 Department of Pathology, Erzincan Binali Yıldırım University, Medical Faculty, Erzincan, Turkey

Date of Submission08-Feb-2021
Date of Acceptance16-Apr-2021
Date of Web Publication15-Nov-2021

Correspondence Address:
Dr. M Tayfur
Department of Pathology, Erzincan Binali Yildirim University, Medical Faculty, Erzincan
Turkey
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/njcp.njcp_68_21

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   Abstract 


Background: Cancer is one of the biggest health problems in the world. Colon adenocarcinoma is the third most common cancer and is the fourth most common cause of cancer deaths. The majority of colon adenocarcinomas originate from a previous adenoma. Cyclin D1 expression and Ki-67 proliferation index increase as the risk of malignancy transformation increases in adenomas. Aims: This study aims to share the results of the Cyclin D1 and Ki-67 studies we performed in colon adenoma and colon adenocarcinoma cases in our hospital with the literature and contribute to the diagnosis and treatment of patients. Materials and Methods: Surgical materials of 40 colon adenocarcinomas and 40 colon adenomas were histopathologically re-evaluated. Cyclin D1 and Ki-67 immunohistochemical staining were applied to these materials. Cyclin D1 and Ki-67 staining rates were compared in colon adenocarcinomas and adenomas. Results: Cyclin D1 and Ki-67 staining rates were increased in colon adenocarcinoma cases compared to colon adenoma. There was a significant difference between the colon adenocarcinoma and colon adenoma case groups in terms of Cyclin D1 and Ki-67 staining scores. Conclusion: In conclusion, immunohistochemical markers such as Cyclin D1 and Ki-67 will be helpful in differential diagnosis when there is difficulty in evaluating routine Hematoxylin-Eosin stained preparations between adenocarcinomas and adenomas.

Keywords: Adenocarcinoma, adenoma, colon, cyclin D1, Ki-67


How to cite this article:
Ayerden D, Tayfur M, Balci M G. Comparison of histopathological findings of the colon adenomas and adenocarcinomas with cyclin D1 and Ki-67 expression. Niger J Clin Pract 2021;24:1737-41

How to cite this URL:
Ayerden D, Tayfur M, Balci M G. Comparison of histopathological findings of the colon adenomas and adenocarcinomas with cyclin D1 and Ki-67 expression. Niger J Clin Pract [serial online] 2021 [cited 2021 Nov 26];24:1737-41. Available from: https://www.njcponline.com/text.asp?2021/24/11/1737/330476




   Introduction Top


Cancer is one of the biggest health problems in the world. Colon adenocarcinoma (CAC) is the third most common cancer and is the fourth most common cause of cancer deaths. The risk of lifelong development in the Western world is 4-5%.[1]

CAC is the most common malignancy of the gastrointestinal system. It is one of the main causes of cancer-related mortality and morbidity worldwide.[2] It is estimated that more than one million new cases of CAC occur worldwide, accounting for 9.7% of all cancers. It is fourth in men after lung, prostate, and stomach carcinomas. It is third in women after breast and uterine cervix carcinomas. It is most frequently seen between 60 and 79 years. Incidence of its increases with age.[3] A large proportion of the CACs originate from an earlier colon adenoma (CA).[4],[5] CAs are caused by dysplastic epithelial proliferation. The risk of developing CAC increases in direct proportion to the number and size of the CA.[6],[7] The risk in CAs smaller than 1 cm is low. In total, 40% of CAs larger than 4 cm have a cancer focus.[2] CAs are examined in three groups: tubular adenoma (TA), tubulovillous adenoma (TVA), and villous adenomas (VA).[6],[8],[9] The incidence of cancer development according to histological types is 2-3% in TA, 6-8% in TVA, and 29%–70% in VA.[8]

CACs are the most common cancer of the digestive tract and more than 50% of them are metastasized.[10],[11] They occur in 11% of all cancer deaths.[12]

CAs are more common in men than in women.[13] The most common localization of sporadic CAs is the rectosigmoid region.[14]

The differential diagnosis of CAC and CA is mainly based on the histopathological feature of routine HE-stained tissues. However, when signs of dysplasia are evident in their CAs, IHC studies are required to distinguish them from CAC.[15]

In the presence of high-grade dysplasia (carcinoma in situ) in a CA, it is assumed that it does not yet have the capacity to metastasize. If the lesion passes into the submucosal area, it is considered as invasive CAC. If a CAC of a sessile polyp is developed, complete removal of the lesion is the only treatment.[8],[16]

The carcinoma development of adenoma is called an adenoma-carcinoma sequence. CAC and CA can often coexist in the same lesion. CA and CAC show similar anatomical distribution. The prevalence rates of CAs and CACs among countries are similar. Endoscopic removal of CAs reveals an 85% reduction in the incidence of CAC. Chromosomal structure, antigenic similarities, the content of DNA, enzyme pattern, and oncogenes show similar characteristics in both CA and CAC.[17]

Cyclin D1 gene is a nuclear protein that plays a role in the transition from G1 to S phase in the cell cycle. The cycle and progression of the cell occur due to Cyclins. Cyclins are involved in all phases of the cycle by complexing with Cyclin-dependent kinases. The cell enters the S phase by providing the transcription of the genes required for entry into the S phase and the synthesis of DNA occurs. It is localized in 11q23. The overexpression of Cyclin D1 due to gene amplification occurs in many malignancies. It was found to be mostly associated with lymph node metastasis poor prognosis. Mutations due to overexpression of Cyclin D1 are common in parathyroid adenomas, mantle cell lymphomas, and other B-cell lymphomas.[18]

Ki-67 is a nuclear protein seen in proliferating cells. It is located on the 10th chromosome.[19] It is mainly monitored in G1, S, M, and G2 phases but not in the G0 phase.[20] It shows the morphological features of cell proliferation in a good way. It is frequently used in tumor grading with mitotic index. In general, a good correlation between Ki-67 staining and mitosis is observed.[21] The percentage of cells showing positive nuclear staining for Ki-67 with IHC indicates proliferation index. This rate increased in aggressive tumors. A high Ki-67 rate is considered to be a poor prognostic factor.[22]


   Material and Methods Top


Approval was obtained from Ethics Committee with the decision dated 25.07.2017 and numbered 11/08. After approval, we re-evaluated 40 cases with CAC and 40 cased with CA (27 cases with TA, 10 cases with TVA, and 3 cases with VA). The CACs and CAs were supplied from the pathology archive. 4-micron-thick sections were taken from these blocks. After deparaffinization, the sections were stained with HE stain. In addition, 4 μm thick sections were taken from the blocks of tumor suspected preparations on positively charged slides for IHC.

After deparaffinization, all of the preparations were placed on a fully automated IHC device. Cyclin D1 and Ki-67 IHC staining were applied to all blocks and positive control was used. The rabbit monoclonal anti-Cyclin D1 (Clone GR005, 1/100 solution, GENEMED) and mouse anti-human monoclonal antibody Ki-67 (Clone K2, ready to use, LEICA) were applied for IHC staining. IHC results were evaluated using light microscopy.

The nuclear staining for Cyclin D1 was considered positive. The staining area and staining intensity obtained for each preparation were multiplied and recorded as a staining score. Statistical studies were performed on this score for Cyclin D1. The percentage of staining area of the cells was scored as 0, 1, 2, 3, and 4. 0: <5% cell staining. 1: 5%–25% cell staining. 2: 26%–50% cell staining. 3: 51%–75% cell staining 4: >75 cells staining. The staining intensity of positive cells was graded as 0, 1, 2, and 3. 0: No staining. 1: weak staining. 2: moderate staining. 3: strong staining.[23]

The nuclear staining for Ki-67 was considered positive. The staining area obtained for each preparation and the staining intensity were multiplied and recorded as staining score. Statistical studies were performed on this score for Ki-67. The percentage of staining area of the cells was scored as 0, 1, 2, and 3: 0: No staining. 1: <10% cell staining. 2: 10%–50% cell staining. 3: in >50% cell staining. The staining intensity of positive cells was graded as 0, 1, 2, and 3. 0: No staining. 1: weak staining. 2: moderate staining. 3: strong staining.[24]

Statistical analysis

Staining scores were summarized categorically and consistently. Categorical variables were expressed as n (%) and continuous variables were expressed as mean ± standard deviation median (min-max) value. The normal distribution assumption was controlled by the Kolmogorov-Smirnov test and tests were selected according to the distribution type. Mann–Whitney U test was used for non-normally distributed scores, the Kruskal–Wallis test was used for nonparametric data analysis and Spearman correlation analysis was used for correlation analysis. A value of P < 0.05 was considered statistically significant. IBM SPSS version 19.0 package program was used for data analysis.


   Results Top


Forty cases diagnosed as CAC and 40 cases diagnosed as CA were evaluated. Of 40 cases with CA, 27 were TA, 10 were TVA, and 3 were VA [Figure 1]a, [Figure 1]b, [Figure 2]a, [Figure 2]b, [Figure 3]a, [Figure 3]b, [Figure 4]a, [Figure 4]b. The ages of CAC cases were between 40-90 years, and CA cases were between 25-84 years. The mean age was 70.1 years in CAC cases and 59.5 years in CA cases. Of the 40 CA cases, 8 (20%) were female and 32 (80%) were male; of 40 CAC cases 21 (52.5%) were female and 19 (47.5%) were male [Table 1].
Figure 1: Tubular adenoma. a. The histopathological appearance of tubular adenoma. (HEX40) b. The histopathological appearance of tubular adenoma. (HEX200) c. Low-score staining with Cyclin D1. (X200) d. Low-score staining with Ki-67. (X200)

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Figure 2: Tubulovillous adenoma. a. The histopathological appearance of tubulovillous adenoma. (HE X100) b. The histopathological appearance of tubulovillous adenoma. (HEX200) c. High-score staining with Cyclin D1. (X200) d. High-score staining with Ki-67. (X200)

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Figure 3: Villous adenoma. a. The Histopathological appearance of villous adenoma. (HEX40) b. The Histopathological appearance of villous adenoma. (HEX200) c. High-score staining with Cyclin D1. (X200) d. High-score staining with Ki-67. (X200)

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Figure 4: Adenocarcinoma. a. The histopathological appearance of adenocarcinoma. (HE X100) b. The histopathological appearance of adenocarcinoma. (HEX400) c. High-score staining with Cyclin D1. (X200) d. High-score staining with Ki-67. (X200)

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Table 1: Comparison of gender and case groups

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Significantly different nuclear staining rates were observed in Cyclin D1, CAC, and CA cases. Staining rates with Cyclin D1 were lower in CA cases than CAC cases. The lowest staining rate was in tubular adenoma and the most staining rate was in villous adenoma in adenoma cases [Figure 1]c, [Figure 2]c, [Figure 3]c, [Figure 4]c. In 40 cases with CAC, the percentage of staining area score 0 was in 5 (12,5%), score 1 was in 18 (45%), score 2 was in 14 (35%), score 3 was in 2 (5%), score 4 was in 1 (2.5%); the staining intensity was (+) in 27 (67.5%), was (++) in 8 (20%), was (+++) in 5 (12.5%). In 40 cases with CA, the percentage of staining area score 0 was in 19 (47.5%), score 1was in 21 (52.5%); the staining intensity was (-) in 2 (5%), was (+) in 27 (67.5%), was (++) in 9 (22.5%), was (+++) in 2 (5%). When the case groups were considered there was a significant difference between CAC and CA in terms of Cyclin D1 staining score (p < 0.001) [Table 2].
Table 2: Comparison of adenocarcinoma and adenoma in terms of Cyclin D1 immunohistochemical staining score

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Significantly different nuclear staining rates were observed in Ki-67, CAC, and CA cases. Similar to Cyclin D1, staining rates with Ki-67 were lower in CA cases than CAC cases. The lowest staining rate was in tubular adenoma and the most staining rate was in villous adenoma in adenoma cases [Figure 1]d, [Figure 2]d, [Figure 3]d, [Figure 4]d. In 40 patients with CAC, the percentage of staining area score 2 was in 11 (27.5%), score 3 was in 29 (72.5%); the staining intensity was (+) in 2 (5%), was (++) in 28 (70%), was (+++) in 10 (25%). In 40 patients with CA, the percentage of staining area score 1 was in 4 (10%), score 2 was in 36 (90%); the staining intensity was (+) in 14 (35%), was (++) in 17 (42.5%), was (+++) in 9 (22.5%). When the case groups were considered there was a significant difference was found between the CAC and CA in terms of Ki-67 staining score (p < 0.001) [Table 3].
Table 3: Comparison of adenocarcinoma and adenoma in terms of Ki-67 immunohistochemical staining score

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   Discussion Top


9.7% of all cancers is CAC. It is fourth in men after lung, prostate, and gastric carcinomas. In women, it is the third most common carcinomas after the breast and uterine cervix.[3] It is the most common malignancy of the gastrointestinal system and one of the main causes of cancer-related mortality and morbidity worldwide.[2] It is most commonly seen between 60-79 years.[3] The mean age of the CAC cases in this study was 70.1 and this finding was similar to the literature. It is equally seen in males and females.[8] In this study, 52.5% of the cases of CAC were female and 47.5% were male and there was an average close to the literature.

It is known that most of the CACs develop from CAs. The risk of developing CAC from CA increases in direct proportion to the number and size of the CA in the colon and varies according to type. The incidence of cancer development according to histological types is 2%–3% in TA, 6%–8% in TVA, and 29%–70% in VA.[8],[9] Most of the CACs and CAs occur in the rectosigmoid region.[8],[14]

Cyclin D1 contributes to many stages of colorectal oncogenesis and can be used as an adjunctive indicator for the risk of malignancy.[25] It has been reported that the increase in Cyclin D1 expression is responsible for the pathological changes in the mucosa in the early stage of colon carcinogenesis by disrupting the cell cycle.[26],[27]

Ki-67 can be evaluated as a prognostic parameter in determining prognosis together with other known prognostic parameters.[28] Ki-67 is a part of oncogenesis and can be used to predict the prognosis in CAC.[29],[30],[31]

In the studies of Nassrat et al.[25] and Toru et al.[26] on CA, it was shown that Cyclin D1 is responsible for pathological changes in the mucosa, adjunctive indicator for the risk of malignancy and overexpression of Cyclin D1 is associated with progression to cancer.

Arber et al.[27] found significant expression of Cyclin D1 on CA and CAC. They reported that increased expression of Cyclin D1 disrupted the cell cycle and that the change in this early stage of colon carcinogenesis was responsible for pathological changes in the mucosa.

In the studies of Sheikh et al.[30] and Radovanovic-Dinic et al.[31] on CA, it was shown that Ki-67 may be useful as prognostic factors and it should be considered as a prognostic parameter together other known histopathological features.

In the study of Lin et al.[29] on CAC, it was found that Ki-67 expression was significantly higher in CAC than CA and normal colorectal mucosal tissue. They explained that Ki-67 is a part of oncogenesis and can be used to predict the prognosis of CAC.

In the study of Kouraklis et al.[32] on CAC, there was a significant correlation between Cyclin D1 levels and Ki-67 expression.

In this study, when Cyclin D1 and Ki-67 staining rates were compared in CAC and CA cases, Cyclin D1 and Ki-67 staining rates were higher in CAC cases. There was a correlation between Cyclin D1 and Ki-67 staining rates in CAC and CA cases. The results of this study were compatible with the literature.

In conclusion, when there is difficulty in evaluating the preparations stained with HE between CAC and CA, using immunohistochemical markers such as Cyclin D1 and Ki-67 will contribute to the solution of the problem.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
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  [Figure 1], [Figure 2], [Figure 3], [Figure 4]
 
 
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