Vascular endothelial growth factor polymorphisms and a synchronized examination of plasma and tissue expression in epithelial ovarian cancers.

In this study, we have analyzed six genetic polymorphisms of the VEGF-A gene and correlated the genetic data with plasma and tissue expression of VEGF-A in epithelial ovarian carcinomas. A total of 130 cases including 95 malignant carcinomas, 17 low malignant potential and 18 benign tumours were studied. rs699947, rs833061, rs1570360, rs2010963, rs1413711 and rs3025039 were studied by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Plasma levels of VEGF-A were estimated by enzyme-linked immunosorbent assay (ELISA) and tissue expression of VEGF-A by immunohistochemistry (IHC). Four polymorphisms of the above excluding rs699947 and rs3025039 showed significant association with malignancy, and we observed the presence of positive correlation between haplotype CCGGCC and increased expression of VEGF-A in both plasma and tissues which also correlated with poor prognosis and recurrence suggesting a probable increase in resistance to treatment in such carriers. Highly upregulated tissue expression of VEGF-A was seen in all epithelial ovarian carcinomas with intensity of expression increasing from benign to malignant cases. ELISA data from our study showed an increase in circulating levels of VEGF-A in malignancies. VEGF-A plasma levels can be employed as a biomarker for high-grade malignancy in epithelial ovarian cancers alongside tissue expression and CA-125 levels. This study is unique due to the fact that a simultaneous analysis of plasma and tissue expression has been demonstrated and is a first such study in epithelial ovarian cancers and representing the Indian population (South-east Asian) synchronized with genetic polymorphism data as well.

BRCA1 promoter hypermethylation and protein expression in ovarian carcinoma--an Indian study.

Mounting evidences suggest that aberrant methylation of CpG islands is a major pathway leading to the inactivation of tumour suppressor genes and the development of cancer. The aim of the current study was to examine the prevalence of the promoter hypermethylation and protein expression of the BRCA1 gene in epithelial ovarian carcinoma (EOC) to understand the role of epigenetic silencing in ovarian carcinogenesis. We studied the promoter methylation of the BRCA1 gene by methylation-specific PCR in a cohort of 88 patients with EOC, 14 low malignant potential (LMP) tumours and 20 patients with benign tumours of the ovary. The expression of the BRCA1 protein by immunohistochemical analysis was carried out in a subset of 64 EOCs, 10 LMP tumours, 10 benign tumours and 5 normal ovarian tissues. The frequencies of methylation in EOCs and LMP tumours were 51.2 and 57%, respectively, significantly higher (p = 0.000 and p = 0.001) in comparison to benign tumours and normal ovarian tissue where no methylation was seen. Expression of BRCA1 was significantly lower in EOCs (p = 0.003). Lack of protein expression correlated with tumour grade and type. The methylation status correlated well with downregulation of BRCA1 expression. Our results clearly demonstrate that hypermethylation of BRCA1 promoter is a frequent event in ovarian cancer. These data support the hypothesis that BRCA1 promoter methylation plays an important role in the functional inactivation of BRCA1. Follow-up clinical data will reveal the impact of BRCA1 methylation on survival.

Relationship between promoter methylation & tissue expression of MGMT gene in ovarian cancer.

BACKGROUND & OBJECTIVES: Epigenetic alterations, in addition to multiple gene abnormalities, are involved in the genesis and progression of human cancers. Aberrant methylation of CpG islands within promoter regions is associated with transcriptional inactivation of various tumour suppressor genes. O 6-methyguanine-DNA methyltransferase (MGMT) is a DNA repair gene that removes mutagenic and cytotoxic adducts from the O 6 -position of guanine induced by alkylating agents. MGMT promoter hypermethylation and reduced expression has been found in some primary human carcinomas. We studied DNA methylation of CpG islands of the MGMT gene and its relation with MGMT protein expression in human epithelial ovarian carcinoma. METHODS: A total of 88 epithelial ovarian cancer (EOC) tissue samples, 14 low malignant potential (LMP) tumours and 20 benign ovarian tissue samples were analysed for MGMT promoter methylation by nested methylation-specific polymerase chain reaction (MSP) after bisulphite modification of DNA. A subset of 64 EOC samples, 10 LMP and benign tumours and five normal ovarian tissue samples were analysed for protein expression by immunohistochemistry. RESULTS: The methylation frequencies of the MGMT gene promoter were found to be 29.5, 28.6 and 20 per cent for EOC samples, LMP tumours and benign cases, respectively. Positive protein expression was observed in 93.8 per cent of EOC and 100 per cent in LMP, benign tumours and normal ovarian tissue samples. Promoter hypermethylation with loss of protein expression was seen only in one case of EOC. INTERPRETATION & CONCLUSIONS: Our results suggest that MGMT promoter hypermethylation does not always reflect gene expression.

Pre-operative plasma VEGF-C levels portend recurrence in epithelial ovarian cancer patients and is a bankable prognostic marker even in the initial assessment of a patient.

PURPOSE: Our explorative study assessed a panel of molecules for their association with epithelial ovarian carcinomas and their prognostic implications. The panel included tissue expression of VEGF-C, COX-2, Ki-67 and eNOS alongside plasma levels of VEGF-C and nitric oxide. METHODS: 130 cases were enrolled in the study. Plasma levels were quantified by ELISA and tissue expressions were scored by immunohistochemistry. The Chi square and Fischer's exact test were applied to examine the impact of markers on clinicopathological factors. Non-parametric Spearman's rank correlation test was applied to define the association among test factors. RESULTS: Plasma VEGF-C levels and COX-2 tissue expression strongly predicted recurrence and poor prognosis (< 0.001). Tissue Ki-67 was strongly indicative of late-stage disease (< 0.001). The aforementioned markers significantly associated with clinicopathological factors. Nuclear staining of VEGF-C was intriguing and was observed to correlate with high grade-stage malignancies, highly elevated plasma VEGF-C, and with recurrence. eNOS tissue expression showed no significant impact while nitric oxide associated positively with ascites levels. Tissue expression of VEGF-C did not associate significantly with poor prognosis although the expression was highly upregulated in most of the cases. CONCLUSION: Plasma VEGF-C holds immense promise as a prognostic marker and the nuclear staining of VEGF-C seems to have some significant implication in molecular carcinogenesis and is a novel finding that commands further robust scrutiny. We present a first such study that assesses a set of biomarkers for prognostic implications in clinical management of epithelial ovarian carcinomas in a pan-Indian (Asian) population.

Altered expression of ß-catenin, E-cadherin, and E-cadherin promoter methylation in epithelial ovarian carcinoma.

The aim of the study was to evaluate the immunoexpression of E-cadherin, ß-catenin, and Ki-67, as well as the promoter methylation of E-cadherin gene in epithelial ovarian cancer (EOC), as well as to find a possible relationship between the immunoexpression and hypermethylation. Promoter methylation was studied using methylation-specific PCR in 86 malignant cases, 14 low malignant potential (LMP) tumors and 19 benign cystadenomas. Immunohistochemical expression was carried out in 64 malignant cases, 8 LMP tumors, and 11 benign cystadenomas. Immunoexpression of E-cadherin was reduced in EOC, while 100 % expression was seen in LMP tumors and benign cystadenomas. An interesting observation was the nuclear expression of E-cadherin in a high percentage of cancers, which showed a positive correlation with Ki-67. Β-Catenin expression showed heterogeneous localization with increased nuclear localization, which was significantly higher in cases that did not express E-cadherin. Promoter methylation of E-cadherin was 36, 14, and 11 % in EOC, LMP tumors, and benign cystadenomas, respectively. Our results suggest that reduced expression of E-cadherin is associated with promoter methylation of E-cadherin gene, in addition to providing evidence for the aberrant nuclear localization of E-cadherin in EOC.

Extranodal natural-killer/T-cell lymphoma, nasal type: An immunomorphological study from a regional cancer institute in India.

Introduction: Extranodal natural-killer/T-cell lymphoma, nasal type (ENKTL), is a rare, aggressive, predominantly extranodal non-Hodgkin lymphoma (NHL) of putative natural-killer (NK) cell and rarely T-cell origin, always associated with Epstein-Barr virus (EBV) infection and characterized by highly distinctive histopathological features with predilection for the upper aerodigestive tract. While the nasal cavity is the prototypical site, less frequently extranasal ENKTL can also occur. The objective of this case series is to study the immunomorphological features of ENKTL from a tertiary cancer centre as the data are sparse from India despite it being a distinct entity with characteristic clinicopathological features. Methods: We identified 11 cases of ENKTL from the departmental archives between January 2015 and June 2018. The clinicopathological and immunohistochemistry (IHC) findings of these tumors were analyzed. EBV encoded RNA (EBER) in situ hybridization (EBER-ISH) for EBV was done in eight cases. Results: The disease was more common in males (male: female ratio 1.8:1) with the mean age of 45 years (range 31-65 years). Sinonasal region was the most common site with 9 cases and skin and penis were involved in one case each. The patient with penile involvement on further investigations was found to have occult nasal involvement, Histomorphological features such as angiocentricity/angioinvasion was seen in seven cases (63.6%) and significant necrosis was present in all 11 cases (100%). All cases were uniformly positive for cytoplasmic CD3 and CD56 with high Ki67 proliferating index and EBER-ISH test for EBV was positive in all the eight cases. Conclusion: ENKTL is an aggressive NHL and should be differentiated from other T- and B-cell lymphomas as the prognosis and therapy differ. Nasal biopsies showing predominant necrosis and atypical lymphoid cells with angiocentricity must raise the suspicion of ENKTL and should be confirmed by immunomorphological and molecular studies.

Multifocal Osteosarcoma: Multiple Primaries or Metastases? A Report of Rare Case and Review of Literature.

INTRODUCTION: Multifocal osteosarcoma (MFOS) is characterized by multicentricity of osseous osteosarcomas, either synchronous or metachronous, without visceral involvement. They account for about 1.5% of all osteosarcomas. Most synchronous MFOS has one dominant lesion with one to four and very rarely five or more secondary lesions. The distal femur followed by the proximal tibia is the most common site of dominant lesions. Its prognosis remains extremely poor even with combined chemotherapy and surgery. CASE REPORT: We describe a rare case of MFOS in a 10-year-old boy who presented with a short history of severe aching pain in the right lower limb following a trivial fall. Initial workup and relevant investigations revealed a synchronous multicentric osteosarcoma with extensive involvement of appendicular and axial skeletal system. The dominant lesion was at the lower end of the right femur with multiple secondary lesions in the right tibia, left femur, bilateral humeri, pelvis, cervical and dorsolumbar spine, ribs, and sternum. The patient received one cycle of doxorubicin and cisplatin-based chemotherapy but unfortunately succumbed to progressive disease, a month after initiation of chemotherapy. CONCLUSION: MFOS is a very rare presentation of osseous osteosarcoma. The non-specific clinical manifestation, despite the presence of generalized skeletal involvement, presents a diagnostic difficulty for both the clinician and the radiologist. Only biopsy and histopathological examination can confirm the diagnosis of this highly malignant disease and help in proper management.

HIV/AIDS-related lymphoma: perspective from a regional cancer center in India.

BACKGROUND: India has the third largest population of people living with HIV/AIDS (PLHA). Lymphoma is the second most common malignancy among PLHA. However, data are lacking regarding HIV/AIDS-related lymphoma (ARL) in India. This study evaluated the epidemiology and clinical outcomes of ARL from a regional cancer center in India. METHODS: This retrospective analysis included cases of ARL between March 2011 and September 2017. Data were obtained from patient record files for the assessment of epidemiology and clinical outcomes. Statistical analysis was performed using GraphPad Prism 6. Comparisons of subtype-specific survivals were performed using log-rank tests. RESULTS: Of 1,226 lymphoma cases, 80 (6.5%) were ARL. Details were available for 70 patients. The median age at diagnosis was 40.5 (9-74) years with a male:female ratio of 2:1. AIDS-defining lymphomas (ADL) constituted 78.6% of cases, while 21.4% had non-AIDS defining lymphoma (NADL). The mean CD4 counts were 193.15±92.85 and 301.93±107.95 cells/µL, respectively (t-test; P=0.0002). Extranodal involvement was present in 55.7%, B symptoms were reported in 60%, and lactate dehydrogenase (LDH) was elevated in 64.3% of patients. The median overall survival times were 6 months for plasmablastic lymphoma (PBL), 23 months for diffuse large B-cell lymphoma (DLBCL), and was not reached for Hodgkin's lymphoma (log-rank test; P=0.0011). Other histological subtype cases were too few to draw meaningful survival outcomes. CONCLUSION: ARL is a heterogeneous disease. Histologic subtype is a major determinant of the clinical outcome. ADL has significantly lower CD4 counts than those of NADL. There is an urgent and unmet need for uniform management guidelines for improving outcomes in this under-represented patient population.

Pro-oncogenic, intra host viral quasispecies in Diffuse large B cell lymphoma patients with occult Hepatitis B Virus infection.

Non Hodgkin lymphoma, predominantly Diffuse Large B-cell Lymphoma (DLBCL) has been reported to have a significant association with Hepatitis B virus (HBV). We investigated the presence of different gene segments of HBV in plasma, B-cells and tumor tissues from DLBCL patients and explored the genetic variability of HBV within and across different compartments in a host using Next Generation Sequencing. Despite all 40 patients being HBV seronegative, 68% showed evidence of occult HBV. Sequencing of these gene segments revealed inter-compartment viral variants in 26% of them, each with at least one non-synonymous mutation. Between compartments, core gene variants revealed Arg94Leu, Glu86Arg and Ser41Thr while X gene variants revealed Phe73Val, Ala44Val, Ser146Ala and Ser147Pro. In tumor compartments per se, several mis-sense mutations were detected, notably the classic T1762A/A1764G mutation in the basal core promoter. In addition, a virus surface antigen mis-sense mutation resulting in M125T was detected in all the samples and could account for surface antigen negativity and occult HBV status. It would be interesting to further explore if a temporal accumulation of viral variants within a favored niche, like patients' lymphocytes, could bestow survival advantage to the virus, and if certain pro-oncogenic HBV variants could drive lymphomagenesis in DLBCL.

Primary gastrointestinal diffuse large B-cell lymphoma: A prospective study from South India.

BACKGROUND: Gastrointestinal tract (GIT) is the most common extranodal site for non-Hodgkin's lymphoma (NHL) and constitutes about 10%-15% of all NHL. This was a prospective study to evaluate the epidemiological, clinicopathological characteristics, and treatment outcome of primary GIT diffuse large B-cell lymphoma (PGIL). MATERIALS AND METHODS: Newly diagnosed patients of PGIL with DLBCL histology were eligible. Lugano staging system was used. All patients were treated with prephase treatment (1 mg vincristine and 100 mg prednisolone) followed by CHOP-based chemotherapy (with or without rituximab) as definitive treatment. RESULTS: A total of 21 patients of PGIL were diagnosed. The median age was 46 years (range: 27-69 years) with male:female ratio of 2:1. Dull aching abdominal pain was the most common presenting complaint. Stomach was the most common site involved (52.4%, n = 11) followed by the colon (23.8%, n = 5). The estimated median survival in patients with Stage IV disease was significantly lower as compared to patients with localized disease (Stage I and II) (6.23 months vs. 23.4 months; P = 0.04). Patients, who did not achieve complete response (CR), had 15.5 times higher risk of death, as compared to those who achieved CR (P = 0.01). CONCLUSIONS: Stomach was the most common site for PGIL. Localized disease and CR after first-line chemotherapy were associated with better survival. A higher cost of rituximab was the prohibitive factor for cure in these patients.

Every distant deposit is not a metastasis: Synchronous primaries do exist.

BACKGROUND: Synchronous occurrence of two malignant tumors is a rare event. With increasing use of sophisticated imaging modalities for staging, synchronous multiple tumors are more commonly detected now. Assuming the second primary malignancy as metastasis will change the intent of treatment from curative to palliative, greater awareness among oncologists is of paramount importance. This study is an example where thorough clinical examination and proper judgment resulted in correct diagnosis and appropriate treatment. MATERIALS AND METHODS: This is a prospective descriptive study. Patients diagnosed with synchronous primary tumors from January 2016 to November 2017 at our center were reviewed. RESULTS: Ten cases of synchronous primary malignancies were detected during this period. A total of 20 primary tumors were diagnosed. Lung carcinoma and gastrointestinal malignancies were the most common (five patients each). The median age was 59.5 years. Seven patients were male. Second primary tumor was suspected in four patients during clinical examination, while in six patients it was suspected on imaging. Even in the presence of two primary tumors, three patients were treated with curative intent. CONCLUSION: Possibility of synchronous second primary malignancy should always be kept whenever a distant deposit is detected at an unusual site. Histopathological evaluation of the lesion before assuming a metastasis will lead to accurate diagnosis, staging, and appropriate treatment.

Primary follicular lymphoma of ileum [corrected] disguised as multiple miliary like lesions: A case report and review of literature.

Primary follicular lymphoma (PFL) of gastrointestinal tract (GIT) is rare and account for 1%-3% of non-Hodgkin lymphoma. Within the small intestine, the PFL is more common in jejunum than in the ileum. Due to low prevalence of the disease, the clinical manifestations are not well known, and diagnosis is usually delayed leading to complications. We herein report a case of PFL of GIT who presented with intestinal obstruction and unique gross morphology. Diagnosis was made by morphology and supported by immunohistochemistry.

Bone marrow involvement at presentation in pediatric non-haematological small round cell tumours.

Pediatric small round cell tumors (SRCT) are a group of neoplasms occurring in children, which have in common a cytomorphology of groups of small round cells with scanty cytoplasm. The common SRCT encountered are neuroblastoma, retinoblastoma, Ewing's sarcoma/peripheral neuroectodermal tumor (PNET), rhabdomyosarcoma and lymphoma which show varying degrees of bone marrow involvement and bone marrow evaluation forms a part of the initial staging procedure. This study was undertaken to evaluate marrow involvement at presentation in pediatric non hematological SRCT. 7833 bone marrow aspirates done over a period of three years in different malignancies were analysed and of these 180 aspirates were performed in patients of pediatric non hematological SRCT at presentation. These cases were evaluated in detail for incidence of marrow involvement. Thirty two (17.7%) cases showed marrow involvement and these cases have been analysed with respect to the primary tumor. The SRCT showing involvement of bone marrow included neuroblastoma (48.8%), retinoblastoma (11.1%), Ewing's sarcoma/PNET (8.6%) and rhabdomyosarcoma (3.2%). These findings are discussed in the light of available world literature.

Atypical teratoid rhabdoid tumor of the central nervous system: Case series from a regional Tertiary Care Cancer Centre in South India.

BACKGROUND: Atypical teratoid rhabdoid tumors (AT/RT) constitute a rare group of pediatric brain tumors. AIM: To study the clinical, histopathological, and immunohistochemical (IHC) profile, management and outcome of children with AT/RT of the central nervous system who presented between the years 2007 and 2015 in a regional tertiary care center in South India. MATERIALS AND METHODS: This was a retrospective study. Demographic and clinical data were obtained from the clinical case files. Archived slides and tissue blocks were retrieved. All cases had hematoxylin and eosin stained sections. IHC was available in all the cases. RESULTS: There were eight cases with the mean age of presentation being 4 years (range: 4 months to 15 years) and with slight male predominance (male:female = 1.66:1). Most of the presenting complaints were due to raised intra-cranial tension. The median duration of symptoms was 0.75 months. About 62.5% of the tumors were infratentorial in location. The tumors were heterogeneous showing variable expression of cytokeratin, epithelial membrane antigen, glial fibrillary acid protein, and synaptophysin. Loss of integrase interactor-1 expression was demonstrated in seven cases in which it was done. Multimodal treatment comprising surgical resection, radiotherapy and chemotherapy was tailored based on location of tumor, resectability and patient's age. The median overall survival was 2.5 months (range: 1.5-30 months). CONCLUSION: Awareness of this tumor is important as it portends a poor outcome in most patients, in spite of multi-modal treatment. Several new molecules which aim to prolong survival and improve quality of life are being developed to combat this enigmatic tumor.

Expression of VEGF-A in Epithelial Ovarian Cancer: Correlation with Morphologic Types, Grade and Clinical Stage.

AIM: The objective of this study was to evaluate the expression pattern of vascular endothelial growth factor A (VEGF A) in epithelial ovarian cancers (EOC) and to correlate the intensity of expression with morphologic types, histologic grade and clinical stage of the disease. METHODS: Tissue microarrays were constructed from paraffin blocks of 78 cases of EOC in duplicate. Immunohistochemical staining for VEGF A was carried out with mouse monoclonal antibody and the intensity was scored independently by two pathologists (CSP and MA). RESULTS: Twenty six of 78 (33.3%) cases of primary malignant epithelial ovarian neoplasm showed high VEGF A expression. Among high expressors, 23 were seen in serous carcinomas, two in undifferentiated carcinomas and one in mixed carcinoma. High expression was not seen in other types like, endometrioid, mucinous and clear cell carcinomas. High VEGF-A expression was also associated high grade and advanced stage of the disease. CONCLUSION: High VEGF-A expression in epithelial ovarian cancer was found to be associated with serous morphology, high grade and advanced stage of the disease. Though some degree of VEGF A expression was seen in most ovarian carcinomas, high expression was seen in only one third of cases and this may help in selecting the patients for targeted therapy with antiangiogenic agents.

Plasma Epstein-Barr virus and Hepatitis B virus in non-Hodgkin lymphomas: Two lymphotropic, potentially oncogenic, latently occurring DNA viruses.

CONTEXT: There is a need to study potential infective etiologies in lymphomas. Lymphocyte-transforming viruses can directly infect lymphocytes, disrupt normal cell functions, and promote cell division. Epstein-Barr virus (EBV) is known to be associated with several lymphomas, especially Hodgkin lymphomas (HLs). And recently, the lymphocyte-transforming role of hepatitis B virus (HBV) has been emphasized. AIMS: The aim of this study was to elucidate the association of two potentially oncogenic, widely prevalent latent DNA viruses, EBV and HBV, in non-HL (NHL). SETTINGS AND DESIGN: In this prospective study, we estimated plasma EBV and HBV DNA in NHL patients. MATERIALS AND METHODS: Peripheral blood was obtained from newly diagnosed, treatment na ïve, histologically confirmed NHL patients. Plasma EBV DNA was quantified by real-time polymerase chain reaction (PCR) targeting Epstein-Barr Nucleic acid 1 while the plasma HBV DNA was detected using nested PCR targeting HBX gene. In a small subset of patients, follow-up plasma samples post-anticancer chemotherapy were available and retested for viral DNA. RESULTS: Of the 110 NHL patients, ~79% were B-cell NHL and ~21% were T-cell NHL. Plasma EBV-DNA was detected in 10% NHLs with a higher EBV association in Burkitt lymphoma (33.3%) than other subtypes. Pretherapy HBV DNA was detected in 21% NHLs; most of them being diffuse large B-cell lymphoma (DLBCL). Moreover, 42% of DLBCL patients had HBV DNA in plasma. Since all patients were HBV surface antigen seronegative at diagnosis, baseline plasma HBV-DNAemia before chemotherapy was indicative of occult hepatitis B infection. CONCLUSIONS: Our findings indicate a significant association of HBV with newly diagnosed DLBCL.

Primary Parotid Lymphoma From A Regional Cancer Center in South India.

UNLABELLED: Primary parotid lymphoma (PPL) is an unusual entity and there is limited data in Indian population. Hence we undertook this retrospective observational study of primary parotid lymphoma at our Center in Southern India. This study includes 7 consecutive cases diagnosed as PPL by tissue biopsy/superficial/deep parotidectomy confirmed by immunohistochemistry between January 2007 and December 2012. RESULTS: Median age was 54 years (range 29- 78 years), and it was more common in males. According to Ann Arbor stage, Advanced stage (stage III and IV) was seen in 2 (28.57%). According to the International Prognostic Index (IPI), most (6) were low risk (85.7%). Overall survival ranged from 1-45 months with median OS of 18 months. To conclude, PPL presents more often in early stage and low IPI score. Surgery +/- chemoimmunotherapy with radiotherapy to the parotid is the standard treatment at present.

Childhood hepatic angiosarcoma--a case report.

Hepatic angiosarcoma (HAS) is an extremely rare liver tumor in children. We report a case of childhood HAS in a six year old girl who presented with acute abdominal pain and fever with a mass in epigastrium. Left hepatic lobectomy was performed with a clinical diagnosis of hepatoblastoma. Histopathological examination revealed features typical of hepatic angiosarcoma. The case is presented for its rarity and to discuss the interrelation between infantile hemangioendothelioma (IHE) and HAS.

Aberrant promoter methylation of the RASSF1A and APC genes in epithelial ovarian carcinoma development.

PURPOSE: Tumor suppressor gene (TSG) silencing through promoter hypermethylation plays an important role in cancer development. The aim of this study was to assess the extent of methylation of the RASSF1A and APC TSG promoters in ovarian epithelial adenomas, low malignant potential tumours and carcinomas in order to reveal a role for epigenetic TSG silencing in the development of these ovarian malignancies. METHOD: The promoter methylation status of the RASSF1A and APC genes was assessed in 19 benign cystadenomas, 14 low malignant potential (LMP) tumours, and 86 carcinomas using methylation specific PCR (MSP). RESULTS: The methylation frequencies of the RASSF1A and APC gene promoters in benign cystadenomas were found to be 37 % and 16 %, respectively. The LMP tumours exhibited RASSF1A and APC gene promoter methylation frequencies of 50 % and 28 %, respectively, whereas the carcinomas exhibited methylation frequencies of 58 % and 29 %, respectively. Methylation of either the RASSF1A or the APC gene promoter was encountered in 58 % of the invasive carcinomas. CONCLUSION: The observed aberrant methylation frequencies of the RASSF1A and APC gene promoters indicate that an accumulation of epigenetic events at these specific TSG promoters may be associated with the malignant transformation of benign cystadenomas and LMP tumours to carcinomas.