Introduction

Cervical carcinoma is one of the most common gynecologic malignancy world wide and a leading cause of death from genital malignancies. Approximately 5, 00,000 new cases of this cancer are diagnosed worldwide each year with the survival rate of only 40 % [1]. In the developing countries cervical carcinoma is ranked second with a relative frequency of 15% of all cancers in women, whereas in the developed countries this cancer is ranked fifth with a relative frequency of 4.4 % [2]. About 1/5 to 1/6 of the total incidence of cervical carcinoma in the world occurs in India [3]. In India, 365.71 million females above the age of 15 are at the risk of developing cervical cancer. It is estimated that about 132,082 women die due to cervical cancer every year, accounting for 26.7% of the world wide incidence. One woman in India die due to cervical cancer every 7 minutes accounting for more than 200 deaths every day The cumulative risk of the incidence of cervical cancer in women in India (age 0-64 yrs) is 2.4% compared to 1.3% for the world[ 4].

Epidemiological studies have shown the high risk Human PapillomaVirus (HPV) to be the most important risk factor and are present in 99.7% of the invasive cervical cancer worldwide [5]. Young age, early marriage, multiple sexual partners, poor genital hygiene, history of abortions, high parity, tobacco and oral contraceptive use,  cigarette smoking, race, low socio economic status have also been identified as significant risk factors for the development of CaCx [6].

Material and Methods

The present study was conducted in the Department of Gynecology and Obstetrics SMGS Hospital, Government Medical College, Jammu and Human Genetic Research cum Counselling Centre, University of Jammu. Cases were selected from patients having complains of excessive vaginal discharge, post coital bleeding, post menopausal bleeding etc. and on per speculum examination with suspected cervical  lesion or unhealthy cervix. Tissue pieces were transferred to the fresh hypotonic solution for 15 minutes at 37⁰c. The material was fixed in methanol and acetic acid (3:1) and the slides were prepared by air drying method (Atkin and Baker, [7]). For conventional cytogenetic study, the prepared slides were subjected to GTG-Banding (Sea bright, [8]). The well spread G-banded metaphase plates were photographed and used for the preparation of their karyotypes. Besides chromosome study, non cytogenetic factors like marital age, religion, high parity etc. have also been studied in all 50 cases.

Observations

Well spread metaphase plates were selected for the preparation of their karyotypes to find out both the numerical and structural chromosomal abnormalities. Numerical chromosomal changes were more common as they were recorded in 95% of growths and structural chromosomal changes were observed in 5% of growths. . In the squamous cell carcinoma cases, aneuploidy was the commonest numerical chromosomal change. Besides aneuploidy, the micronuclei were also detected in both Squamous cell carcinoma and Adenocarcinoma. The frequency of micronuclei increased significantly in the Adenocarcinoma of the cervix. Chromosomal changes in the form of Trisomy 3, 8, 11, 12, 13, 17, 18, 19, 20, 21 and 22 were observed in squamous cell carcinoma. Monosomy of chromosome 3 was commonly seen in the adenocacinoma of the cervix.

Majority of the females in the present study belonged to age group of 50-69 yrs (Table 1). Incidence of CaCx was found to be common (68%) in the females who were Para three whereas 40% Para two (Table 2). According to the area distribution of these patients, 81.6% belonged to rural areas and only 18.4% belonged to urban area (Table 3). Incidence of CaCx was found to be higher in Hindus as compared to Muslims (Table 4).More than 58.3% of the females under study were married at the age of 21-25(Table 5). When ages at first issue of these patients were taken into consideration about 55% of the patients belonged to age group 19-22and 28.33% belonged to the age group 16-19 (Table 6).

Discussion

Different risk factors associated with the development of cervical carcinoma detected in the present study have been analyzed in detail. The findings are summarized below:

Maximum numbers of the patients (40%) were in the age group of 51-60 (Table 1). The present findings with respect to age were found consistent with the observations made by Spanos et al. [9], Parkin et al. [10], Miller [11] and Misra et al. [12].

Table 1: Patients belonging to different age group.

Majority of the patients were multiparous (Table 2). Various workers like Wahi et al. [13], Brinton et al. [14], Aras and Pai [15] and Munoz et al. [16] also recorded a strong relationship of the risk of cervical carcinoma to the number of live births. Trauma to the cervix during delivery could be the possible explanations but alternative mechanisms that warrant exploration include increased susceptibility to infection through immunosuppression, hormonal influences and dietary deficiencies (Brinton et al. [14]).

Table 2: Relation of cervical cytopathologies with parity.

Maximum number of the patients in this study belonged to the rural areas (81.6%) and 18.4% belonged to urban areas (Table 3). Our findings were consistent with the reports of Coker et al. [18], Gajalakshmi and Shanta [19] that the incidence of cervical cancer is higher among the patients living in the rural areas. Since the recognized risk factors like illiteracy, low socioeconomic status early menarche, poor genital hygiene is widely prevalent in the rural population (Dutta et al. [20])

Table 3: Number of patients belonging to rural/urban background.

The incidence of cervical malignancy was significantly lower in Muslims (Table 4). This was in accordance with the study done by Wahi et al. [21] and Gajalakshmi and Shanta [19] that circumcision as practiced by Muslim could account for the lower incidence of cervical carcinoma as compared to Hindu community.

Table 4: Number of patients belonging to different religions.

The frequency of this malignancy was higher in women who were married between 21-25 years (Table 5). These findings were consistent with findings proposed by Misra et al. [12].

Table 5 Relationship of cervical cytopathologies with age at Marriage.

62%of women had first issue at the age of 19-22 yrs (Table 6). This was in accordance with the study conducted by Dutta et al. [20] Thompson [22] and Varghese [23] that young age at first pregnancy is also a risk factor for CaCx.

 Table 6: Relationship of cervical cytopathologies with age at 1^st Issue.

Chromosomal instability as manifested by increase in aneuploidy and structural chromosomal aberrations is believed to play a critical role in the intermediate to late stages in the development of cervical malignancies. Numerical chromosomal aberrations like aneuploidy and tetraploidy have earlier been reported in women diagnosed with precancerous and cancerous cervical lesions (Hesselmeyer et al. [24] Southern et al. [25] and Giannoudis et al. [26]). The presence of elevated levels of trisomy and aneusomy in the cervical carcinogenesis are consistent with the previous findings by various workers like Atkin et al. [27], Nguyen et al. [28] and Segers et al. [29].

Workers like Duensing et al. [30] and Skyldberg et al. [31] proposed that polyploidization of squamous cells seems to be a direct effect of HPV by inhibiting the formation of the mitotic apparatus in the prometaphase of the cell cycle. Centrosome disturbances occurring in the presence of episomal virus genome have been described as a possible mechanism of endoreduplication.

Chromosomal aberrations in cervical cancer have been extensively characterized by both classical and molecular cytogenetics. Chromosomes 3 and 17 have been reported to be frequently involved in squamous cell carcinoma (Kirchhoff et al. [32] and Hidalgo et al. [33]).

Besides chromosomal changes, micronuclei have also been recorded. The formation of MN in the dividing cells could be  the result of chromosomal breakage due to unrepaired or mis-repaired DNA lesions, or chromosome malsegregation due to mitotic malfunction. These events may be induced by oxidative stress, exposure to clastogens or aneugens, genetic defects in cell cycle checkpoint and/or DNA repair genes, as well as deficiencies in nutrients required as co-factors in DNA metabolism and chromosome segregation machinery (Kimura et al. [34], Umegaki. and Fenech, [35], Rajagopalan et al. [36], MacGregor, [37] and Fenech, [38].  All these events can cause the formation of MN through chromosomal rearrangements, altered gene expression or aneuploidy, effects associated with the chromosome instability phenotype often seen in cancer Rajagopalan et al.[39], Fenech [40] Fenech  et al.[41] and Ames and Wakimoto,  [42].

From the present study and the available literature it is evident that the chromosome analysis in different stages of carcinoma of the cervix provides an additional tool for the diagnosis of the carcinoma. The cytogenetic study if supplemented with molecular cytogenetic study especially Fluorescent in situ hybridization (FISH) will aid further in pinpointing the exact location of the gene/genes involved in the origin and progression of the tumor. The present work is therefore an addition to the existing literature on the cytogenetic study of the carcinoma of the cervix. The significance of chromosomal changes either in the origin of the tumor or in the progression of tumor is therefore debatable and more cytogenetic work needs to be carried out both by conventional and molecular cytogenetic techniques so as to find out the exact role of chromosomal changes in the origin and progression of carcinoma of cervix in particular and other carcinomas in general.

Acknowledgement

Authors are extremely thankful to the J&K State Council for Science and Technology, Department of Science and Technology, J & K State for providing financial support to conduct the research work.

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