A cross-sectional study of immunohistochemical evaluation of surface epithelial ovarian tumors

Vikas Pandey; Jyotirmayee Mishra; Pralhad S Potdar

doi:10.4103/mgmj.mgmj_75_21

ORIGINAL ARTICLE

Year : 2022 | Volume : 9 | Issue : 1 | Page : 84-88

A cross-sectional study of immunohistochemical evaluation of surface epithelial ovarian tumors

Vikas Pandey¹, Jyotirmayee Mishra², Pralhad S Potdar³
¹ Department of Pathology, Government Medical College, Ambikapur, Surguja, Chhattisgarh 497001, India
² Department of Pathology, Veer SurendraSai Institute of Medical Sciences and Research, Burla, Odisha 768017, India
³ Department of Community Medicine, Government Medical College, Ambikapur, Surguja, Chhattisgarh 497001, India

Date of Submission	09-Oct-2021
Date of Acceptance	01-Feb-2022
Date of Web Publication	23-Mar-2022

Correspondence Address:
Dr. Vikas Pandey
Department of Pathology, Government Medical College, Ambikapur, Surguja, Chhattisgarh 497001.
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/mgmj.mgmj_75_21

Abstract

Background: Ovarian cancer is one of the most common malignancies in female patients. In recent years, immunohistochemistry (IHC) has emerged as an important tool in the diagnosis of ovarian tumors. The study aimed to assess estrogen receptors (ERs), progesterone receptors (PRs), Her-2-neu, and Ki-67 by IHC in surface epithelial ovarian tumors and to correlate the findings with different variables. Materials and Methods: It was a cross-sectional study. Oophorectomy/salpingo-oophorectomy/cystectomy specimens were included in this study. IHC was done on 10% neutral buffer formalin-fixed paraffin-embedded tissue sections by using Dako FLEX Ready to use mouse monoclonal antibodies and DakoEnvision^TM FLEX/HRP detection reagent. Results: The study includes 81 cases of surface epithelial ovarian tumors (a benign serous tumor [20], a benign mucinous tumor [18], a borderline mucinous tumor [5], low-grade serous carcinoma [8], high-grade serous carcinoma [19], mucinous carcinoma [7], endometrioid carcinoma [2], borderline Brenner tumor [1], and malignant Brenner tumor [1]. ER had higher expression in malignant cases (51.33%) than in benign cases (15.8%). PR had higher expression in malignant tumors (54.05%) incomparable to benign (18.42%) and borderline tumors (16.66%). PR had higher expression in high grade. Expression of Her-2-neu positivity was found to be 29.7% out of the total 81 cases. Her-2-neu was found in 11 high-grade tumors among 31 malignant cases. CA-125 levels were significantly higher in malignant ovarian tumors (P = 0.0143). Proliferation activity was considered low if proliferation index (PI) <10% and high if PI >10%. The study showed high PI in malignant tumors. Conclusion: Expression of these marks in adjunct to H&E diagnosis may prove beneficial in differentiating benign, borderline, and malignant cases, in which a diagnosis of borderline cases based on sole H & E is doubtful.

Keywords: ER, Her-2-neu, Ki-67, PR, surface epithelial ovarian tumors

How to cite this article:
Pandey V, Mishra J, Potdar PS. A cross-sectional study of immunohistochemical evaluation of surface epithelial ovarian tumors. MGM J Med Sci 2022;9:84-8

How to cite this URL:
Pandey V, Mishra J, Potdar PS. A cross-sectional study of immunohistochemical evaluation of surface epithelial ovarian tumors. MGM J Med Sci [serial online] 2022 [cited 2022 May 17];9:84-8. Available from: http://www.mgmjms.com/text.asp?2022/9/1/84/340591

Introduction

Ovarian cancer is one of the most frequent cancers in female patients. Recent years have witnessed significant development in the use of immunohistochemistry (IHC) in diagnostic ovarian pathology.^[1] An elevated level of estrogen receptors (ERs) and progesterone receptors (PRs) could significantly predict ovarian cancer patients’ outcomes.^[2] Her-2-new gene is amplified and/or overexpressed in 25–30% of ovarian cancers and is associated with poor prognosis. Ki67 is a proliferation marker helpful in predicting disease outcomes in any type of malignancies including ovarian neoplasm.^[3]

The present study was an attempt to evaluate the significance of ER, PR, Ki-67, Her-2-neu expression by IHC in ovarian tumors and to correlate these findings with histopathological type, tumor stage, grade, and CA-125 levels.

Materials and methods

General study details

The study was designed as an observational cross-sectional study in an institutional setting in Medical College, Burla, Odisha. The study period was 2 years (2015–2017). The approval for the study was sought from the Institutional Research and Ethics Committee (VIREC-reg. no-ECR/861/Inst/OR/2016 and no/2015/P-I-RP/151). Informed consent was taken from the study subjects willing to participate in the study. Proforma designed to gather uniform necessary information was used for every case. Eighty-one cases of surface epithelial ovarian tumor were received during the study period.

Participants

The study included histopathologically diagnosed cases of surface epithelial tumor, irrespective of age. Non-neoplastic lesions, non-epithelial tumors, metastatic tumors, and HER-2-neu equivocal cases were the exclusion criteria for the study.

Variables

Independent variables were histopathological type, tumor stage, tumor grade, and CA-125 levels. Dependent variables were ER, PR, Ki-67, and Her-2-neu expression.

Study methodology

This study was conducted on surgically resected tumor specimens from patients undergoing total abdominal hysterectomy with bilateral/unilateral scalping-oophorectomy and those histopathologically diagnosed with surface epithelial ovarian tumors. The specimens were fixed in 10% neutral buffered formalin overnight. Grossing was performed as per TATA Grossing Manual Guidelines.^[4] Adequate tissue bits were submitted which were routinely processed manually and paraffin-embedded tissue blocks were made. H&E-stained slides were examined for the presence of epithelial ovarian malignancies. Tumors were classified and graded as per WHO classification 2014^[5] and M. D. Anderson Cancer Centre Grading System.^[6] TNM and FIGO staging was done on each case.^[7] Thereafter, the most suitable tissue block was selected for IHC evaluation. IHC was using Dako FLEX Ready to use mouse monoclonal antibodies (optimally diluted) and DakoEnvision^TM FLEX/HRP detection reagent. For the determination of ER and PR expression, normal breast tissue was taken as a positive control. A known positive carcinoma case was taken as a positive control for the determination of Her-2-neu expression. For negative control, the primary antibody will be excluded. ALLRED score was performed for scoring of ER and PR. HER-2-neu and Ki-67 scoring were performed as per laid criteria.^[8],[9],[10]

Statistics

A formal sample size calculation was not made, as this was a cross-sectional study limited to a specific timeframe. The raw scores for the tests were calculated, and the corresponding percentile or cut-off scores were obtained from the manuals. Statistical analysis was done using the Statistical Package for the Social Sciences (SPSS Inc., Released 2011, SPSS for Windows, Trial Version 20.0, Chicago, IL, USA). Descriptive statistics and tests such as the χ² test, Fisher’s exact test, and the independent sample T-test were used to analyze the data. Descriptive statistics were used to determine the frequency, mean, and standard deviation of different demographic variables and IHC markers. P < 0.05 was considered statistically significant.

Results

The present study included 81 patients histopathologically diagnosed with surface epithelial ovarian tumors [Table 1]. The age of the study subjects ranged from 14 to 70 years (mean 42.32 years and median 43 years). A majority of malignant cases were noted in patients over 40 years of age. Among 81 cases, 37 cases (45.6%) were reported as malignant, 38 cases (46.91%) as benign, and 6 cases (7.4%) as borderline [Table 1]. The most common tumor subtype was serous for both benign and malignant categories. The most common tumor subtype was mucinous for the borderline category. The mean age of patients was 48.59 years in malignant, 41.60 years in borderline and 36.78 years in the benign group.

Table 1: Expression of immunohistochemical markers and CA-125 levels in histological subtypes of surface epithelial ovarian tumors

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CA-125 levels were higher in malignant tumors (mean 558.37 IU/mL) followed by borderline (mean 40.6 IU/mL) and lowest in benign ovarian tumors (mean 23.6 IU/mL) (P-value <0.05). CA-125 was raised in all subtypes (P < 0.05) [Table 2].

Table 2: Immunohistochemical expression and CA-125 level correlation with grades of tumors

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ER expression was noted in 15.8% in benign cases (ALLRED score 0–4/8) and 51.53% in malignant (ALLRED score 5–7/8) cases [Figure 1]. ER expression was not observed in any of the mucinous tumors. A significant correlation was found between ER expression and the age of cancer patients (P < 0.05). ER expression was numerically and statistically significant in high-grade tumors (P < 0.05) [Table 2].

Figure 1: Malignant Brenner’s tumor showing strong ER positivity, total score 7 (IHC DAB Chromogen, ×100)

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PR expression was seen higher in malignant tumors than in benign and borderline tumors. PR expression was found to be higher in high-grade tumors (P > 0.05) [Figure 2]. A significant correlation was not observed between PR expression and the age of patients. ER and PR expressions were more in serous carcinoma and not significantly associated with the FIGO stage. ER and PR expressions were maximum in the age group of 40 years and above. HER-2-neu expression was found only in high-grade tumors (P <0.05) [Table 2] and [Figure 3].

Figure 2: High-grade serous carcinoma showing strong PR positivity (total score 7) (IHC DAB Chromogen, ×s400)

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Figure 3: Mucinous carcinoma showing strong HER-2-NEU positivity (3+) (IHC DAB Chromogen, ×100)

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The present study showed the highest proliferation index (PI) in malignant tumors (47.2%), followed by borderline tumors (8.36%) and lowest in benign tumors (1.36%) (P < 0.05). In the malignant group, the malignant Brenner tumor had the highest (68%), followed by serous carcinoma (45.8%) and lowest in mucinous carcinoma (P <0.01). Ki-67 index was higher in advanced stage (P < 0.05). It was higher in high-grade tumors (P > 0.05) [Table 2] and [Figure 4]. Insignificant co-expression of ER and PR together was found in the present study (P > 0.05). An insignificant association was found between markers (ER, PR, her-2-neu, and Ki67) (P > 0.05). A strong association was observed among ER+, PR+, HER2-neu+ markers with high-grade malignant tumors (P < 0.05). The mean of CA125 levels and the Ki-67 index were higher in triple-positive tumors. ER-, PR-, HER-2-neu-constituted one-fifth (21.67%) of the total number of cases.

Figure 4: Malignant Brenner’s tumor, showing high Ki-67 index, 68% (IHC DAB Chromogen, ×400)

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Discussion

Higher expression of ER (51.35%) seen in malignant tumors correlates to the study of Verma et al.^[11] (36%). ER expression was not seen in any of the mucinous tumors of the ovary, which was similar to the observations of Kriplani and Patel.^[12] PR expression of malignant tumor (54.05%) was higher than benign and borderline tumors, similar to the observations of Verma et al.^[11] Comparison of ER and PR expressions in malignant surface epithelial tumors in the present study showed variability in them. The study results of ER and PR expressions (51.35% and 54.05%, respectively) were found similar to the observations of Kühnel et al.^[13] in malignant surface epithelial ovarian tumors. A significant difference was seen in the positivity of ER and histological subtypes. Expression of ER seen in the majority of serious subtypes was similar to the observations of Verma et al.^[11] ER expression was not observed in mucinous tumors, which was in agreement with observations of Sylvia et al.^[14] and Vang et al.^[15] PR expression in various histological subtypes of ovarian cancer did not show a significant association (P > 0.05). ER and PR expressions were highest in serous carcinoma and significantly low in mucinous tumors of the ovary, similar to the literatures published by Høgdall et al.,^[2] Sylvia et al.,^[14] Lindgren et al.,^[16] and Garg et al.^[17] PR expression (100%) in all the cases of endometrioid carcinoma (2) in the present study was found comparable to Sutton et al.^[18] The present study showed a significant ER expression in correlation with high-grade tumors (P <0.05). ER was positive in 66.66% of high-grade tumors. No significant correlation was observed between PR expression and high-grade tumors, similar to the findings of Verma et al.^[11] The present study and observations of Verma et al.^[11] showed an insignificant association between ER and PR expressions and FIGO stage.

The present study showed HER-2-neu expression only in malignant tumors (P <0.01), which is similar to the observations of Sylvia et al.^[14]and Goel et al.^[19] The present study showed that HER-2-neu expression in the malignant tumor was not significant with age (P > 0.05). The study of Goel et al.^[19] revealed no association between HER-2-neu expression and age. The present study was comparable for HER-2-neu expression with Goel et al.^[19] and Berchuck et al.^[20] Mucinous carcinoma showed higher HER-2-neu expression 57%, followed by serous carcinoma 25.9%. The present study showed a significant association of high-grade tumors with HER-2-neu expression, similar to the studies of Sylvia et al.,^[14] Sarkar et al.,^[21] and Hellström et al.^[22]

Th eKi-67 index was found to be significantly higher in malignant tumors (P <0.01) and lowest in benign tumors similar to Sylvia et al.,^[14] Gursan et al.,^[23] Naik et al.,^[24] and Choudhury et al.^[25] The present study, however, found no association between markers when correlated among them. This was also observed in a study by Sylvia et al.^[14]

Triple-negative tumors showed significant association with low grades, whereas they did not correlate with tumor subtype and FIGO stage. The mean Ki-67 index and mean CA-125 had lower values in triple-negative tumors than in triple-positive tumors, similar to Sylvia et al.^[14]

Conclusion

Successful treatment of one of the most lethal gynecological malignancies is still depending on early detection, whereas the efficacy of screening in ovarian cancer detection and prognosis is still ambiguous. Expression of different markers (ER, PR, and Ki-67 index and Her-2-neu) in different types, stages, and grades of tumors has suggested their role and significance in malignant tumors.

Her-2-neu positivity is seen only in malignant tumors. CA-125 and Ki-67 index revealed a higher level in malignant tumors than in benign and borderline tumors. Thus, a panel of these markers would help in differential and early detection of borderline, benign, and malignant cases and warrant targeted hormone-based and anti-HER-2-neu treatment.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

Ethical consideration

Ethical approval for undertaking the proposed research study was obtained from the Office of the Institutional Research and Ethics Committee, vide letter no. VIREC-reg no-ECR/861/Inst/OR/2016 and no/2015/P-I-RP/151, dated October 21, 2017.

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