Associations between Single Nucleotide Polymorphisms from the Genes of Chemokines and the CXCR2 Chemokine Receptor and an Increased Risk of Endometrial Cancer.

Significant relationships with endometrial cancer were demonstrated, both for CCL2, CCL5, and CXCL8 chemokines and for the chemokine receptor CXCR2. The reported case-control study of genetic associations was designed to establish the role of selected single nucleotide polymorphisms (SNPs) of the CCL2, CCL5, CXCL8, and CXCR2 genes in the onset and progression of endometrial cancer. This study was conducted on 282 women, including 132 (46.8%) patients with endometrial cancer and 150 (53.2%) non-cancerous controls. The genotypes for CCL2 rs4586, CCL5 rs2107538 and rs2280789, CXCL8 rs2227532 and -738 T>A, and CXCR2 rs1126580 were determined, using PCR-RFLP assays. The AA homozygotes in CCL5 rs2107538 were associated with more than a quadruple risk of endometrial cancer (p ≤ 0.050). The GA heterozygotes in the CXCR2 SNP were associated with approximately threefold higher cancer risk (p ≤ 0.001). That association also remained significant after certain adjustments, carried out for age, diabetes mellitus, arterial hypertension, or endometrial thickness above 5 mm (p ≤ 0.050). The A-A haplotypes for the CCL5 polymorphisms and T-A-A haplotypes for the CCL2 and CCL5 SNPs were associated with about a twofold risk of endometrial cancer (p ≤ 0.050). In conclusion, CCL2 rs4586, CCL5 rs2107538 and rs2280789, and CXCR2 rs1126580 demonstrated significant associations with an increased risk of endometrial cancer.

MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) in endometriosis - review of literature.

Endometriosis is a disease of the female genital organs, the causes of which are not fully understood. Recent studies have shown that non-coding RNAs (ncRNAs) like long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) can contribute to the pathogenesis of endometriosis. Profiling of miRNA and lncRNA expression is carried out using state-of-the-art molecular biology techniques (RT-PCR, sequencing, microarray analysis). The use of the latest technologies may make it possible to establish a genetic profile, which is a promising prospect for early diagnosis of endometriosis. In the future, genetic testing may become the gold diagnostic standard and eliminate invasive laparoscopy. In the case of endometriosis, it is important to extend the research to molecular aspects, which may facilitate the diagnosis of the disease or indicate new (based for example ncRNA) treatment methods. The paper presents the latest data on the importance of miRNA/lncRNA in endometriosis.

The Utility of Rectal Water Contrast Transvaginal Ultrasound for Assessment of Deep Bowel Endometriosis.

Deep infiltrating endometriosis (DIE) is characterized by the presence of endometrial tissue outside the uterine cavity that infiltrates at least 5-mm deep below the peritoneal layer. Imagining examinations are the first-choice methods to detect DIE. The aim of this study is to assess whether rectal water contrast transvaginal sonography (RWC-TVS) can be a useful tool for the estimation of the size of deep bowel endometriotic nodules. This retrospective study includes 31 patients subjected to RWC-TVS who underwent surgery due to deep bowel endometriosis between January 2021 and December 2022. Nodule dimensions measured via ultrasound were compared to those of histopathological samples taken after surgery. In total, 52% of patients had endometriosis limited only to the intestines, 19% had endometriotic nodules located at uterosacral ligaments and posterior vaginal fornix, 6% at the anterior compartment, and 13% at a different location. Additionally, 6% of patients had nodules at more than two locations. In all but one case, the intestinal nodules could be seen on RWC-TVS images. The largest nodule dimension measured via RWC-TVS and the size of the equivalent histopathological sample correlated (R = 0.406, p = 0.03). Thus, RWC-TVS allows for the detection of DIE and moderate estimation of the nodule sizes and should be practiced during a diagnostic process.

Long Non-Coding RNA SNHG4 Expression in Women with Endometriosis: A Pilot Study.

BACKGROUND: Endometriosis is a chronic disease of the genital organs that mainly affects women of reproductive age. The analysis of long non-coding RNA (lncRNA) in endometriosis is a novel field of science. Recently, attention has been drawn to SNHG4, which is incorrectly expressed in various human diseases, including endometriosis. AIM: The aim of this pilot study was to analyze the expression of lncRNA small nucleolar RNA host gene 4 (SNHG4) and to investigate its significance in endometriosis. MATERIAL AND METHODS: LncRNA SNHG4 expression was investigated in paraffin blocks in endometriosis patients (n = 100) and in endometriosis-free controls (n = 100) using a real-time PCR assay. RESULTS: This study revealed a higher expression of SNHG4 in endometriosis patients than in controls. A statistically significant relationship between expression level and SNHG4 was found in relation to The Revised American Society for Reproductive Medicine classification of endometriosis, 1996, in the group of patients with endometriosis. CONCLUSION: This pilot study has revealed that gene expression in SNHG4 plays an important role in the pathogenesis of endometriosis.

Analysis of Long Non-Coding RNA (lncRNA) UCA1, MALAT1, TC0101441, and H19 Expression in Endometriosis.

Endometriosis is a disease of complex etiology. Hormonal, immunological, and environmental factors are involved in its formation. In recent years, special attention has been paid to genetic mechanisms that can have a significant impact on the increased incidence of endometriosis. The study aimed to analyze the expression of four long non-coding RNA (lncRNA) genes, UCA1, MALAT1, TC0101441, and H19, in the context of the risk of developing endometriosis. The material for genetic testing for the expression of lncRNA genes were tissue slices embedded in paraffin blocks from patients with endometriosis (n = 100) and the control group (n = 100). Gene expression was determined by the RT-PCR technique. The expression of the H19 gene in endometriosis patients was statistically significantly lower than in the control group. A statistically significant association was found between H19 gene expression in relation to The Revised American Society for Reproductive Medicine classification of endometriosis (rASRM) in the group of patients with endometriosis. Research suggests that H19 expression plays an important role in the pathogenesis of endometriosis.

Chemokine expression in patients with ovarian cancer or benign ovarian tumors.

Introduction: Chemokines play a crucial role in tumor growth and progression according to proangiogenic and immunosuppressive action. The aim of this study was to investigate the serum levels of selected chemokines in patients with ovarian cancer or benign ovarian tumors to assess their role in tumorigenesis and their potential use in preoperative diagnosis of an adnexal mass. Material and methods: The study group consisted of 59 women with ovarian cancer: 17 epithelial ovarian cancer (EOC) patients and 42 women with benign ovarian tumors. We measured in sera obtained preoperatively the level of CA125 and a panel of 5 chemokines - CX3CL1/fractalkine, CXCL1/GRO-α, CXCL12/SDF-1, CCL20/MIP-3α and IL-17F - using the chemiluminescence method with multiplexed bead based immunoassay. Results: CX3CL1 was significantly elevated in sera of advanced ovarian cancer patients compared to women with benign ovarian tumors. The significant elevation of CXCL1 was also observed (both early and advanced stages). A similar pattern was present with the standard ovarian cancer marker CA125. In our patients with endometriotic cysts CA125 levels were significantly higher than in women with other benign tumors, whereas all analyzed chemokines had similar serum titers in patients with endometriotic vs. other benign ovarian cysts. Conclusions: CX3CL1 and CXCL1 are elevated in sera of EOC patients, which indicates their role in cancer development. Moreover, they might be useful in preoperative differential diagnosis of ovarian tumors, especially as they were not elevated in cases of endometriosis.

miRNAs in Cancer (Review of Literature).

MicroRNAs (miRNAs) are short, noncoding, single-stranded RNA molecules that regulate gene expression at the post-transcriptional level by binding to mRNAs. miRNAs affect the course of processes of fundamental importance for the proper functioning of the organism. These processes include cell division, proliferation, differentiation, cell apoptosis and the formation of blood vessels. Altered expression of individual miRNAs has been shown in numerous cancers, which may indicate the oncogenic or suppressor potential of the molecules in question. This paper discusses the current knowledge about the possibility of using miRNA as a diagnostic marker and a potential target in modern anticancer therapies.

Endometriosis: Epidemiology, Classification, Pathogenesis, Treatment and Genetics (Review of Literature).

Endometriosis is a "mysterious" disease and its exact cause has not yet been established. Among the etiological factors, congenital, environmental, epigenetic, autoimmune and allergic factors are listed. It is believed that the primary mechanism of the formation of endometriosis foci is retrograde menstruation, i.e., the passage of menstrual blood through the fallopian tubes into the peritoneal cavity and implantation of exfoliated endometrial cells. However, since this mechanism is also observed in healthy women, other factors must also be involved in the formation of endometriosis foci. Endometriosis is in many women the cause of infertility, chronic pain and the deterioration of the quality of life. It also represents a significant financial burden on health systems. The article presents a review of the literature on endometriosis-a disease affecting women throughout the world.

The Genetic Background of Endometriosis: Can ESR2 and CYP19A1 Genes Be a Potential Risk Factor for Its Development?

Endometriosis is defined as the presence of endometrial foci, localized beyond their primary site, i.e., the uterine cavity. The etiology of this disease is rather complex. Its development is supported by hormonal, immunological, and environmental factors. During recent years, particular attention has been focused on the genetic mechanisms that may be of particular significance for the increased incidence rates of endometriosis. According to most recent studies, ESR2 and CYP19A1 genes may account for the potential risk factors of infertility associated with endometriosis. The paper presents a thorough review of the latest reports and data concerning the genetic background of the risk for endometriosis development.

Is serum anti-Müllerian hormone (AMH) assay a satisfactory measure for ovarian reserve estimation? A comparison of serum and peritoneal fluid AMH levels.

BACKGROUND: Clinical cases have been reported with women who got pregnant with confirmed low serum anti-Müllerian hormone (AMH) concentrations, thus demonstrating that low serum AMH concentration cut-points could be fairly specific for poor ovarian response (POR) to gonadotrophin stimulation, but not for pregnancy. That observation prompted the question whether serum AMH concentration accurately corresponded to the whole amount of AMH secreted by granulosa cells. OBJECTIVES: To measure AMH levels in peritoneal fluid and their correlations with serum AMH concentrations. MATERIAL AND METHODS: The reported study involved 48 female patients, aged 18-40 years, diagnosed with benign ovarian cysts and qualified for a laparoscopic cystectomy. Prior to surgery, the ovarian reserve was assessed using serum AMH concentration assay. The peritoneal fluid was also collected during the laparoscopy and AMH concentrations in peritoneal fluid were measured. RESULTS: The AMH present in the peritoneal fluid strongly correlated with AMH levels in blood serum (r = 0.54; p < 0.001) and higher serum AMH concentrations corresponded to higher AMH concentrations in the peritoneal fluid. There was also a significant correlation between AMH levels in serum and in peritoneal fluid, collected from patients with endometrioma and other benign cysts (r = 0.61; p = 0.001 vs r = 0.43; p = 0.03). CONCLUSIONS: The AMH is present in the peritoneal fluid and its concentrations significantly correlate with AMH levels in serum. The assessment of AMH concentration in the peritoneal fluid may be a valuable complement to the evaluation of ovarian reserve and the diagnosis of infertility after adnexal surgery.

An Analysis of ESR2 and CYP19A1 Gene Expression Levels in Women With Endometriosis.

AIM: The analysis of oestrogen receptor (ESR2) and cytochrome P450 family 19 subfamily A member (CYP19A1) gene expression in the context of the risk for endometriosis development. MATERIALS AND METHODS: Tissue specimens, collected from patients with endometriosis (n=100) and from control patients (n=100) embedded into paraffin blocks, provided the material for genetic studies, oriented towards the expression of ESR2 and CYP19A1 genes. The gene expression was assessed by the reverse transcription-polymerase chain reaction technique. RESULTS: Higher expression levels of ESR2 gene were demonstrated in the patients with endometriosis in comparison with the healthy controls. The expression intensity of CYP19A1 gene was associated with endometriosis, manifested as abdominal wall nodules. A relationship was observed between CYP19A1 gene expression and the Revised American Society for Reproductive Medicine classification in the group with ovarian endometrioid cysts, as well as in the group with peritoneal endometriosis. CONCLUSION: This study suggests the significant role of ESR2 and CYP19A1 gene expression in the pathogenesis of endometriosis.

Polymorphisms in the 3'UTR Region of ESR2 and CYP19A1 Genes in Women With Endometriosis.

OBJECTIVE: ESR2 and CYP19A1 genes play a major role in the hormonal control of women with endometriosis. The aim of the study was to analyze single nucleotide polymorphisms (SNPs) in the 3'UTR region of ESR2 and CYP19A1 genes. The study aimed at localisation of new polymorphisms, the nucleotide variants of which determine the level of susceptibility to endometriosis. STUDY DESIGN: The study included n = 200 patients: 100 with endometriosis and 100 healthy controls. The Sanger's sequencing method was applied for polymorphism analysis. RESULTS: Statistically significant correlations were identified between new, not previously described, two SNPs of ESR2 gene and endometriosis: rs4986938 (G>A) and rs928554 (A>G). In the case of rs4986938 polymorphism, the genotype AA was found to decrease the risk of endometriosis (OR = 0.24 95 % PU 0.05-1.22, p = 0.04). Analysis of the rs928554 polymorphism revealed that the occurrence of the AG genotype reduced the risk of endometriosis (OR = 0.38 95 % PU 0.21-0.71, p = 0.002). There were no differences in the distribution of genotypes of the polymorphisms rs10046 (C>T) and rs4646 (C>A) of CYP19A1 gene between patients and control. CONCLUSIONS: Further studies are necessary in groups with higher numbers of patients to explain whether the above-mentioned polymorphisms may be the risk factors for endometriosis.

Association of SNPs in CDKN2A (P14ARF) Tumour Suppressor Gene With Endometrial Cancer in Postmenopausal Women.

BACKGROUND/AIM: This research was aimed to evaluate the association between three selected single nucleotide polymorphisms (SNPs) within the CDKN2A (P14ARF) tumour suppressor gene and the incidence of endometrial cancer (EC) in postmenopausal women. PATIENTS AND METHODS: The study included 194 postmenopausal women; 144 with EC and 50 non-cancer controls. Genotypes in P14ARF rs3088440, rs3731217 and rs3731245 polymorphisms were assayed using PCR-RFLP and confirmed by sequencing. RESULTS: Regarding the rs3088440 polymorphism, CT, and CT-TT genotypes, were more prevalent among EC patients than in controls (OR=5.55, p=0.023, OR=5.29, p=0.027; and OR=2.92, p=0.023, respectively). The T allele within rs3088440 was more prevalent in EC females than in controls (χ2=4.7, p=0.030). Considering rs3731217, TG and TG-GG genotypes were less prevalent among EC (OR=0.34, p=0.024 or p=0.023; and OR=0.38, p=0.035, respectively). CONCLUSION: Polymorphisms in the CDKN2A gene are associated with EC in postmenopausal women.

Anti-Müllerian hormone as a marker of abortion in the first trimester of spontaneous pregnancy.

OBJECTIVE: To assess anti-Müllerian hormone (AMH) levels as a marker of early abortion in the first trimester among women younger than 35 years. METHODS: Prospective study of women aged 18-34 years with a spontaneous pregnancy at less than 12.6 gestational weeks in Lódz, Poland, between January 2017 and November 2018. Cases of anembryonic abortion and assisted conception were excluded. Blood samples were collected and assayed for serum AMH levels. Data were compared between women with an embryo with no cardiac activity by ultrasound (n=30) and those with a normal embryo (n=33) by using Statistica12 software. RESULTS: The 10th and 90th percentiles of serum AMH concentration among control women were used to identify a reference AMH range (1.1-4.5 ng/mL). Risk of pregnancy loss in the first trimester was found to be higher for both low AMH (<1.1 ng/mL; relative risk [RR], 3.66; 95% confidence interval [CI], 2.1-6.4; P<0.001) and high AMH (>4.5 ng/mL; RR, 3.0; 95% CI, 1.61-5.59; P<0.001). CONCLUSIONS: Both very low and very high AMH concentrations were found to significantly increase the risk of abortion in the first trimester of pregnancy. Serum AMH might be a valuable marker to predict the risk of early abortion.

Analysis of the results of invasive diagnostic procedures in patients referred to gynecologic department due to abnormal uterine bleeding.

INTRODUCTION: Abnormal uterine bleeding (AUB) is one of the most common reason for visits to gynecologists. Endometrial biopsy is a routine procedure in gynecological practice to detect the etiology of AUB and to exclude precancerous and cancerous lesions of the endometrium. The aim of this study was to assess the causes of AUB among women, who had undergone invasive diagnostics due to AUB. MATERIAL AND METHODS: This study was carried among 531 women, who had undergone invasive diagnostics due to AUB between January 2018 and December 2018. Women were divided into premenopausal (with perimenopausal) and postmenopausal groups. Transvaginal ultrasound was performed. Endometrial thickness was compared with histopathological results in each subgroup and statistically analyzed. The incidence of histopathological findings and rate of anemia were also analyzed. RESULTS: In our series of patients the most common cause of AUB based on histopathological results was endometrial polyp, both before and after menopause. The most frequent pathologies at ultrasound findings were leiomyomas and endometrial polyps. The incidence of taken together: atypical hyperplasia and endometrial cancer was significantly higher in postmenopausal group (8.58%) than in pre- and perimenopausal (1.35%, p = 0.0001). The median endometrial thickness, both before and after menopause, was significantly greater in patients with pathological than with nonpathological endometrium. 31% of women with abnormal uterine bleeding before menopause and 10% after menopause had anemia. CONCLUSIONS: Measurements of endometrial thickness seems to be acceptable initial diagnostic tool to distinguish between benign and pathological endometrial changes both before and after menopause.

Cobas 4800 HPV detection in cervical samples of Polish women.

INTRODUCTION: Long-term infection with human papillomavirus (HPV) is the cause of cervical cancer and its precursor - cervical intraepithelial neoplasia (CIN). The presence of HPV infection can be presumed in more than 99% of cases of cervical cancer worldwide. The introduction of DNA testing for the presence of HPV has increased the effectiveness of screening programs for the detection of this cancer. This study aimed to analyze the prevalence of high risk HPV DNA (HR HPV) in females from Poland. MATERIAL AND METHODS: The study was performed on 280 cervical smear samples. In this work we used the Roche Cobas 4800 HPV test to detect the HR HPV in cervical smear samples. RESULTS: 56 patients (20%) proved to be positive regarding HPV-16 DNA and 40 patients (14.28%) regarding HPV-18 DNA. In overall assessment, in 94 patients (33.57%) we detected oncogenic HPV subtypes, other than the two mentioned above. In 90 patients (32.14%) no high risk HPV was detected. CONCLUSIONS: The Roche Cobas 4800 HPV test is a viable, effective, easy and quick tool in detecting high risk HPV DNA.

One-year follow-up of ovarian reserve by three methods in women after laparoscopic cystectomy for endometrioma and benign ovarian cysts.

OBJECTIVE: To determine the long-term impact of laparoscopic cystectomy for endometriomas and benign cysts on ovarian reserve and selection of the most effective method of assessment. METHODS: The present study was carried out between November 2013 and December 2016. Participants were assigned to laparoscopic cystectomy for diagnosed unilateral benign ovarian cysts and divided into groups: the endometrioma group (EG) (n=35) and the other benign ovarian tumor group (OG) (n=35). Before and at 3 and 12 months after the procedure, transvaginal ultrasonography was performed to assess antral follicle count (AFC) and ovarian volume (OvVol); laboratory tests were ordered for anti-Mullerian hormone (AMH) serum concentration assays. Pregnancy rates were counted in a 12-month follow-up. Statistica12 software was used for analysis. RESULTS: The present study included 70 women aged 18-40 years. AMH serum concentration decreased significantly 3 months after laparoscopic cystectomy (4.89 ± 3.66 ng/mL to 3.45 ± 3.37 ng/mL; P<0.001). A greater decrease of AMH concentrations was observed in the EG (45.39% vs 14.87%; P=0.021). Twelve months of observation revealed a suppression in the drop of the AMH concentration, while AFC and OvVol remained unaffected. The likelihood of spontaneous pregnancy was three times higher in the OG (hazard ratio [HR] 3.57, 95% confidence interval [CI] 1.08-12.5). CONCLUSION: There was a significant decline in AMH levels in the EG 3 months after cystectomy. No further fall in AMH concentration was observed in the 12-month follow-up. The serum AMH concentration could be considered a valuable marker for ovarian reserve assessment after laparoscopic cystectomy.

Analysis of preoperative blood platelet parameters in terms of diversity of epithelial ovarian cancer.

Smouldering inflammation, thrombocytosis, and platelet hyper-reactivity are linked to malignancy. The relationships between preoperative diagnostic blood morphology parameters and cancer have been the focus of much interest, because some of these parameters are correlated with advanced cancer stages and poor patient survival rates. This study aimed to perform an observational, retrospective analysis of the intradiversity of blood platelet parameters in patients with different International Federation of Gynaecology and Obstetrics (FIGO) stages and different histological types of epithelial ovarian carcinomas (EOC), and also an analysis of the overall survival rate.In all, 94 EOC patients were included in this analysis (23 mucinous, 33 serous, 20 undifferentiated, 14 endometrioid, and 4 clear cell carcinoma cases). Peripheral blood samples were collected and analyzed before drug or surgical treatment.The platelet-to-neutrophil ratio (PNR) was related to the histological type of EOC, particularly mucinous carcinoma. In patients with mucinous cancer, the PNR was significantly lower compared with patients with nonmucinous cancer, and this parameter distinguished between mucinous and nonmucinous groups of patients (area under receiver-operating characteristic [ROC] curve 0.721 ±â€Š.056; sensitivity 82.6%; specificity 61%; P < .001; ROC analysis), regardless of the FIGO stage. Moreover, elevated PNR values were correlated with lower survival rate of EOC patients.The reduced PNR, similar to the lower level of cancer antigen 125, is characteristic for mucinous ovarian carcinoma patients. Moreover, elevated PNR index might correlate with poor survival of patients.

Sub-optimal primary surgery leads to unfavorable immunological changes in ovarian cancer patients.

Primary cytoreduction, followed by chemotherapy, is a standard treatment of patients with epithelial ovarian cancer (EOC). However, the effectiveness of this treatment depend on various elements e.g. type of operation. It is accepted that optimal surgery correlates with longer survival of patients. The other element, an efficiency of immune system after surgical intervention although important is less elucidated. The aim of this study was to establish the impact of optimal and sub-optimal operation on immunological status of EOC patients regarding also their overall survival (OS). On the day of primary cytoreduction and 7days after, the selected serum immunological parameters were determined in 49 patients with confirmed EOC. We found that, the level of immunosuppressive (interleukin 10; transforming growth factor-ß - TGF-ß1) and pro-inflammatory (interleukin-6 and 8) cytokines was significantly higher in the group of patients with advanced stage of disease, compared to early stage. However, the number of circulating CD3+, CD4+ or CD8+ cells, CD19+ and NK cells was similar in both group of EOC patients. The overall survival of patients who underwent optimal cytoreduction was significantly higher than that in whom only sub-optimal surgery was performed. Sub-optimal cytoreduction only partially weakened the serum level of TGF-ß1 and IL-8 and what is more enhanced the number of circulating CD4+CD25+high cells in patients with advanced stage of disease. Sub-optimal surgery and high post-operative level of TGF-ß1 increased the hazard ratio for patients. Besides, we noticed that the high pre-operative concentration of TGF-ß1 could distinguish all EOC patients (independently of FIGO classification) for whom optimal or sub-optimal surgery would be applied. Sub-optimal debulking resulted in higher immunosuppression and lower OS of EOC patients.

New variants near RHOJ and C2, HLA-DRA region and susceptibility to endometriosis in the Polish population-The genome-wide association study.

OBJECTIVE: Endometriosis is a common gynaecological disease, associated with severe pelvic pain and reduced fertility; however, molecular mechanisms remain largely unknown. Genome-wide association studies (GWAS) are able to identify genetic loci, which can play significant role during endometriosis development. AIM: The study aimed at localisation of new genes and chromosomal loci, the nucleotide variants of which determine the level of susceptibility to endometriosis. STUDY DESIGN: Blood samples from 171 patients with endometriosis were used as material for studies. The patients were recruited to the study at the Department of Operative Gynaecology of the Institute of the Polish Mother's Memorial Hospital in Lodz. A control group (n=2934) came from the POPULOUS collection registered at Biobank Lab, Department of Molecular Biophysics, University of Lodz. DNA of the patients with endometriosis was compared with DNA of women free from that disease, the comparison being supported by GWAS. RESULTS: Genome-wide significant correlation was identified between one new, not previously described, single nucleotide polymorphism (SNP), rs10129516, localised on chromosome 14 in intergenic region between PARP1P2 and RHOJ genes (p=1.44×10-10, OR=3.104, 95% CI=2.329-4.136) and endometriosis. We have also identified significant association with endometriosis of 18 SNPs localised on chromosome 6 in position range 31883957 - 32681631 (C2 and HLA-DRA genes region) with the lowest observed p value for rs644045 in C2 gene (p=2.04×10-8, OR=1.955, 95% CI=1.541-2.480). CONCLUSION: Reported GWAS identified the novel loci associated with endometriosis in Polish women, not previously reported. The most interesting observation shown in our study are regions associated with susceptibility to endometriosis of loci located near C2, HLA-DRA and RHOJ genes. RESULTS: of that study did not correspond to previously published data about polymorphism in that regions and further evaluations are necessary in groups with higher numbers of patients to explain whether the above-mentioned genetic variant may be the risk factor for pathogenesis of endometriosis.