Ovarian tumors are a diverse group of neoplasms that display a range of clinical behaviours, histological features, and prognoses. These tumors are the most prevalent gynecological cancers and represent a significant cause of cancer-related morbidity and mortality in females globally. The World Health Organization (WHO) classifies ovarian tumors into three major categories based on the cell of origin: epithelial tumors, germ cell tumors, and sex cord-stromal tumors [2]. Epithelial ovarian tumors are the most common type and account for 90% of all ovarian tumors. Ovarian cancer continues to present a poor outlook for patients because patients receive late-stage diagnoses and there are limited tools available for effective screening tests. Therefore, understanding the molecular processes and pathological mechanisms of ovarian tumors is essential for developing better patient screening methods and treatment strategies.

Cell cycle control, DNA maintenance, and apoptosis regulation are the core functions of the tumor suppressor gene p53 [3]. The p53 gene mutation has emerged as one of the primary genetic tumor alterations found in human cancers, together with ovarian tumors. Immunohistochemical (IHC) measurement of p53 protein is a common substitute for mutation detection because p53 protein build up typically results in impaired tumor protective capability [4]. The expression of p53 protein overlaps with high-grade serous carcinomas among ovarian tumors because of its status as the most aggressive type of epithelial ovarian cancer. P53 expression is strongly linked to advanced tumor progression, unfavourable treatment outcomes etc [5]. Consequently, researchers have considered p53 to be a promising biomarker.

Understanding the histopathological features of these tumors and their correlation with clinical outcomes is crucial for developing effective treatment strategies. Clinicopathological studies play a vital role in discerning tumor behavior and tailoring patient management plans. Immunohistochemical analysis of p53 markers in clinicopathological studies leads to improved diagnosis of ovarian tumors and a better understanding of their prognostic characteristics. The patterns of p53 expression support clinicians in distinguishing between borderline ovarian tumors and malignancies [6]. This also helps identify tumors with unique biological characteristics. The evaluation of p53 status guides individualized therapeutic strategies. In modern oncology, targeted therapies have become increasingly important for treatment. These therapies often focus on restoring the function of the tumor suppressor protein p53 and manipulating downstream signalling pathways to halt tumor progression. This study aimed to investigate the frequency of p53 expression, as determined by immunohistochemistry, in different types of ovarian tumors. The findings will contribute to a deeper understanding of p53's role in tumorigenesis and its potential implications in diagnosis and treatment.

This is a prospective study conducted in the Department of Pathology, Mahatma Gandhi Memorial Hospital, Warangal, Telangana. A total of 120 cases were included in the study. Clinicopathological details were collected, which included age, presenting complaints, surgery performed, histopathological grading, and p53 immunohistochemical marker.

Inclusion criteria

1. All the cystectomy and oophorectomy specimens
2. Total abdominal hysterectomy with salpingo-oophorectomy specimens of histologically proven primary ovarian tumors.

Exclusion criteria

1. Congenital lesions and inadequate samples.
2. Metastatic ovarian tumors.

Specimen Collection and Fixation

The obtained specimens were immediately fixed in 10% buffered formalin to preserve tissue architecture and prevent autolysis. This process was done for a minimum of 24 hours to ensure optimal preservation of details.

Gross Examination and Sectioning: The fixed specimens were subjected to gross examination. Each specimen was described carefully with details of its dimensions, weight, color, consistency, and any visible abnormalities such as cysts, solid areas, hemorrhage or necrosis. Sections were taken from different representative areas of the tumor including peripheral and central regions. Any areas showing distinct morphological features were included in the section. The tissues were processed by a Leica automatic tissue processor. The processed tissue bits were embedded in paraffin blocks as per standard protocol. The blocks were allowed to solidify and then trimmed to expose the tissue surface for sectioning. Approximately 3 - 4 µm thick sections were prepared with microtome. The sections were placed on a water bath to remove wrinkles and then mounted on to glass slides. The staining was done with Hematoxylin and Eosin (H&E) stain as per the standard protocol. The stained slides were examined under a light microscope. The tumors were classified based on the World Health Organization (WHO) classification of ovarian tumors.

Immunohistochemical Staining for p53

Immunohistochemical staining was conducted to assess p53 expression levels in ovarian tumor tissues. The tissue sections underwent paraffin removal followed by rehydration. Antigen retrieval was performed using heat-induced epitope retrieval (HIER). The sections were then incubated with a primary antibody specific to p53, followed by treatment with a detection system that utilized a secondary antibody. After the addition of chromogen, the staining was visually examined under a microscope. P53 expression was assessed based on nuclear staining and the intensity of staining. A tumor was classified as p53-positive if more than 5% of tumor cells exhibited strong nuclear staining, in accordance with established immunohistochemical protocols.

Statistical analysis

All the available data was refined, segregated, and uploaded to an MS Excel spread sheet and analysed by SPSS version 22 in Windows format. The continuous variables were represented as mean, standard deviation, and percentages. The categorical variables were calculated by chi-square analysis for the p values. The values of p (<0.05) were considered as significant.

In this study, the age group varied between 15 and 87 years. The youngest patient was 15 years old, presented with an abdominal mass, and was diagnosed with Mucinous cystadenoma. The oldest patient was 87 years old, presented with an abdominal mass, and was diagnosed with Fibroma. Age distribution of ovarian tumors is shown in Table 1. Incidence was more common between the 2nd- 5th decade.

Table 1: Showing the distribution of the cases based on the age groups

Based on histological subtypes, the most common age group for benign tumors was 21- 40 years, borderline tumors were 21- 50 years, and malignant tumors were 41- 60 years (Table 2). In total, there were 18 patients with malignant ovarian tumors and among them, 9 cases were in the 4th – 5th decades.

  Table 2: Age distribution among histological types

In this study, mass per abdomen was the commonest symptom which was present in 50% of cases. The next common symptom was pain abdomen present in 33% of cases. Other symptoms like menorrhagia, mass per vaginum, and white discharge per vaginum were present in 17% of cases. Among 120 cases, 94 (78%) were benign, 8 (7%) were borderline, and 18 (15%) were malignant (Fig. 1). Out of 120 ovarian tumors, 87 cases were surface epithelial tumors, 7 cases were sex cord-stromal tumors, and 26 cases were germ cell tumors. Surface epithelial tumors were the most commonly encountered group in the present study. The distribution among surface epithelial tumors in this study is shown in Table 3.

Table 3. Distribution of surface epithelial tumors

Malignant serous tumors were graded according to the recent 2-tier system of classification. High-grade serous carcinomas were more common than low-grade (Table 4).

Table 4: Distribution of serous carcinomas

In the present study, 7 cases were sex cord-stromal tumors, of which 5 were fibromas and 2 were granulosa cell tumors. The granulosa cell tumors showed circumscribed tumor tissue with cells arranged in sheets, nests, cords, and microfollicular patterns (Call-Exner bodies). Fibromas revealed a circumscribed tumor tissue with bland spindle cells arranged in storiform and cellular fascicular patterns. 26 germ cell tumors were encountered in the present study all of which were mature teratomas. Tumors showed the presence of squamous epithelium and dermal appendages, mucinous acini, fat, cartilage, and gastrointestinal epithelium.

P53 expression in ovarian tumors: 17 out of 120 cases were immunohistochemically positive for p53, of which 13 were malignant and 4 were borderline. 5 malignant cases were negative for p53. The expression of p53 was highest among serous cystadenocarcinomas (10/10 cases) of which 3 were low grade and 7 were high grade. Followed by mucinous cystadenocarcinomas (3/6 cases). 2 granulosa cell tumors were p53 negative. Among borderline tumors, 2/5 cases of borderline mucinous tumors were positive and 3/5 were negative for p53. 2/3 cases of borderline serous tumors were positive for p53 and 1/3 was negative.

The ovaries are complex organs where both malignant and benign tumors can develop [7]. Due to their intricate structure and cyclical physiological processes, multiple tumor types can originate from the ovaries [8]. The diagnosis of ovarian tumors remains a challenge in gynecological oncology due to their varied presentations and the complications they pose in clinical practice. Ovarian cancer is the second most common type of malignant gynecologic tumor and leads to the highest mortality rate among female genital cancers [9, 10]. This heterogeneity in ovarian cancer arises from the presence of multiple precursor lesions, varied responses to treatment, and differing mechanisms behind disease progression. Oral contraceptives have shown a significant protective effect against ovarian cancer, as ovulation is considered a major factor in its development [8]. Epidemiological data suggests that approximately one in 55 women will develop ovarian cancer at some point during their lifetime.

Early diagnosis of ovarian cancer significantly improves survival rates, although common

symptoms such as abdominal pain or bloating often result in delayed medical intervention. Accurate histological classification of ovarian tumors is critical, as it directly influences treatment decisions, diagnostic accuracy, and the prediction of patient prognosis. Diagnostic markers for ovarian cancer include the tumor suppressor protein p53, as well as other markers like epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER-2/neu). Emerging biomarkers such as MUC16 (CA125) and HE4 are promising for early detection and prognosis [11]. The p53 protein plays a key role in regulating the cell cycle, DNA repair, and apoptosis [12]. Alterations in p53 expression patterns are frequently observed in the development of epithelial ovarian cancer, contributing to genomic instability. P53 antibodies are often detected in tumors of the breast, lung, colon, and ovaries. Immunohistochemistry has proven to be a valuable diagnostic tool for identifying ovarian carcinomas. The detection of p53 expression is a simple yet powerful method for providing prognostic information for ovarian cancer patients. This biomarker is especially useful for distinguishing high-grade serous carcinomas from other types of surface epithelial malignancies.

The evaluation of p53 expression through immunohistochemistry (IHC) was conducted on 120 ovarian tumor samples collected over a two-year period at MGM Hospital, Warangal. The majority of affected patients were aged between 20 and 50 years. Tumor distribution followed standard patterns seen in previous studies, with 94 benign cases, 8 borderline tumors, and 18 malignant tumors. Among the tumor types, surface epithelial tumors accounted for 72.5% of cases, germ cell tumors for 21.6%, and sex cord-stromal tumors for 5.8%. Mucinous cystadenomas and mature teratomas were the most frequently observed epithelial tumors. The most common subtype of cancerous tumors was borderline mucinous cystadenomas. For serous carcinoma samples, 30% were classified as low-grade and 70% as high-grade. Mucinous cystadenocarcinomas made up 33.3% of malignant epithelial tumors. The sex cord-stromal tumor group included five cases of fibromas and two cases of granulosa cell tumors. Additionally, all 26 germ cell tumors were identified as mature teratomas [14, 15].

The analysis of p53 immunohistochemistry (IHC) testing in 120 tumor cases revealed that 17 (14.2%) were positive for p53 expression. No p53 positivity was found in benign tumors. Among borderline tumors, 50% tested positive for p53, indicating a significant proportion of these tumors exhibit p53 expression. In the malignant category, 13 tumors were p53-positive, with the distribution being 41% high-grade serous carcinomas (HGSC), 17% low-grade serous carcinomas (LGSC), and 17% mucinous carcinomas. Granulosa cell tumors, however, showed no p53 expression, remaining either absent or negative for p53. Notably, positive p53 expression, especially with a +3 score on IHC, was most frequently observed in HGSC cases, highlighting a strong association between p53 positivity and this tumor type. Overall, p53 expression seems to serve as a marker for malignancy, particularly for HGSC, and is absent in benign and granulosa cell tumors, suggesting its potential use in distinguishing between malignant and benign tumors. Data collection for 18 borderline and malignant tumor cases was available for 24 months. Omental deposits developed in three patients alongside two recurrent cases which led to the death of four individuals. Eleven remained disease-free. Several studies have shown a relationship between p53 expression levels and poor patient survival yet researchers are unsure about their statistical significance [16, 17]. The research demonstrates how p53 functions in ovarian tumors yet emphasizes the necessity of molecular diagnostic tools for improved treatment strategies [18, 19]. The improvement of patient results depends heavily on ongoing research dedicated to p53 studies along with investigations concerning additional prognostic indicators.

Limitations

This study is an institution-based one and has a small sample size of 120 cases. Therefore the results obtained may or may not reflect the actual histological pattern and age distribution of ovarian tumors among Indian women.

Accurate diagnosis of ovarian tumors can be rendered in most cases by correlating the clinical presentation, gross and microscopic features. Immunohistochemistry is essential in certain ovarian tumors with doubtful diagnoses. In the present study, immunohistochemical markers were useful in the accurate diagnosis of high-grade serous carcinoma. Surface epithelial tumors are the most common neoplasm of which mucinous cystadenoma is the commonest. The ratio of benign to malignant ovarian neoplasms is 5:1. P53 expression was overexpressed in malignant tumors. Detecting p53 mutations by immunohistochemistry in surface epithelial tumors helps to understand the pathogenesis of low and high-grade serous carcinomas. P53 is a simple method that provides robust prognostic information for patients with ovarian carcinomas. This biomarker is very useful to identify high-grade serous carcinomas from other surface epithelial malignancies.

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