BRCA1, Ki67, and β-Catenin Immunoexpression Is Not Related to Differentiation, Platinum Response, or Prognosis in Women With Low- and High-Grade Serous Ovarian Carcinoma

ARID1A, NOTCH and WNT Signature in Gynaecological Tumours

Ovarian cancer (OC) is among the deadliest gynaecologic malignancies in the world. The majority of OC patients are diagnosed at an advanced stage, with high-grade serous OC (HGSOC). The lack of specific symptoms and suitable screening strategies lead to short progression-free survival times in HGSOC patients. The chromatin-remodelling, WNT and NOTCH pathways are some of the most dysregulated in OC; thus their gene mutations and expression profile could serve as diagnostic or prognostic OC biomarkers. Our pilot study investigated mRNA expression of the SWI/SNF chromatin-remodelling complex gene ARID1A, NOTCH receptors, WNT pathway genes CTNNB1 and FBXW7 mRNA expression in two OC cell cultures as well as 51 gynaecologic tumour tissues. A four-gene panel consisting of ARID1A, CTNNB1, FBXW7 and PPP2R1A was used to investigate mutations in gynaecologic tumour tissue. All seven analysed genes were found to be significantly downregulated in OC when compared with non-malignant gynaecologic tumour tissues. NOTCH3 was also downregulated in SKOV3 cells when compared to A2780. Fifteen mutations were found in 25.5% (13/51) of the tissue samples. ARID1A predicted mutations were the most prevalent with alterations detected in 19% (6/32) HGSOC and 67% (6/9) of other OC cases. Thus, ARID1A and NOTCH/WNT-pathway-related changes could be useful diagnostic biomarkers in OC.

Single nucleotide polymorphisms in breast cancer susceptibility gene 1 are associated with susceptibility to lung cancer

BRCA1 is a tumor suppressor that has been found to be involved DNA synthesis during cell replication. In a recent study, the single nucleotide polymorphism (SNP), rs799917, in BRCA1 was found to be associated with the development and progression of various types of tumor. In the present study, the association between rs799917 and susceptibility to lung cancer was evaluated in a Han Chinese population in the Liaoning Province of China. The BRCA1 rs799917 genotypes (C/C, C/T and T/T) were analyzed using TaqMan quantitative PCR in 682 patients with lung cancer and 694 healthy controls, and the results were analyzed using a Student's t-test, a χ² test and logistic regression analysis. Individuals carrying the C/T or T/T genotype had a lower risk of lung cancer compared with those carrying the C/C genotype [odds ratio (OR), 0.741; P=0.021; and OR, 0.610; P=0.011, respectively). The C/T + T/T genotype group had an even lower risk (OR, 0.709; P=0.005) compared with that in the C/C genotype group. In the stratified analyses of non-smokers, individuals with the C/T or T/T genotype had a lower risk of developing lung cancer compared with that in those carrying the C/C genotype (OR, 0.681; P=0.013; and OR, 0.569; P=0.021, respectively). The stratified analyses of the BRCA1 rs799917 polymorphism based on pathological type, chemotherapy and radiotherapy, showed that in the squamous cell carcinoma, non-chemotherapy and non-radiotherapy subgroups, individuals with the T/T genotype had a lower risk of lung cancer compared with that in those carrying the C/C genotype (OR, 0.454; P=0.007; OR, 0.485; P=0.002; and OR, 0.599; P=0.020, respectively). In conclusion, the T allele of the rs799917 SNP in BRCA1 was associated with a lower risk of lung cancer in the ethnic Han Chinese population in Liaoning Province and may represent a protective factor against lung cancer.

BRCA1 Expression by Immunohistochemistry and Prognosis in Ovarian Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Homologous recombination deficiencies are associated with increased platinum sensitivity and potential response to poly (ADP-ribose) polymerase inhibitors in epithelial ovarian cancer. As an alternative to germline testing or somatic tumor sequencing, BRCA1 deficiency can be detected by immunohistochemistry and might predict homologous recombination deficiencies.

OBJECTIVE

This study aimed to assess the association between BRCA1 expression by immunohistochemistry and the prognosis of patients with epithelial ovarian cancer.

METHODS

We conducted a systematic review and meta-analysis following the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement. We searched PubMed, EMBASE, Web of Science, and Scopus databases through July 2019. Reference lists of selected articles were screened for further studies. We conducted qualitative synthesis and meta-analyses of hazard ratios for overall survival and progression-free survival.

RESULTS

Of 41 studies of BRCA1 expression using immunohistochemistry, 18 evaluated the association of BRCA1 expression with patient survival (2738 cases). The loss of BRCA1 expression was associated with improved overall survival (hazard ratio = 0.67, 95% confidence interval 0.57-0.77) and progression-free survival (hazard ratio = 0.70, 95% confidence interval 0.58-0.84).

CONCLUSIONS

Negative BRCA1 expression assessed by immunohistochemistry was associated with a better prognosis in epithelial ovarian cancer.

A new approach to epithelial-mesenchymal transition diagnostics in epithelial tumors: double immunofluorescent staining and flow cytometry

A new method of double immunofluorescent staining for flow cytometry has been created to evaluate quantitative expression of mesenchymal protein vimentin only in epithelial cells of a solid tumor that is a mix of different origin cells. De novo vimentin expression is strongly associated with epithelial-mesenchymal transition and therefore is a metastatic potential marker of epithelial tumor cells. In comparison with semiquantitative available methods, the proposed one has several advantages, such as the accurate measurement of the marker's expression, and minimization of spatial and temporal tumor heterogeneity. Clinical validation of the method has revealed inverse correlation between the quantitative index of epithelial-mesenchymal transition level and progression-free survival using Kaplan-Meier curves and the COX proportional hazards ratio in 32 ovarian cancer patients.

Ki67 expression as a predictor of chemotherapy outcome in low-grade serous ovarian cancer

OBJECTIVE

Low-grade serous ovarian cancers characterize a unique clinical pattern and lower chemotherapy responsiveness. The expression level of Ki67 is associated with differences in prognosis; however, this has not yet been evaluated in regard to predicting the outcome of therapy.

METHODS

Patients with low-grade serous ovarian cancers were identified in an institutional database. Receiver-operator characteristics (ROC) curve analysis was performed to find cut-off values of Ki67 to discriminate patients with residual tumor mass after surgery from maximal debulked patients: therapy response and therapy-free interval (TFI).

RESULTS

A total of 68 patients with low-grade serous ovarian cancer were identified. All patients underwent surgery. 61 (89.7%) patients received platinum-based first-line chemotherapy; of these 61 patients, 13 (21.3%) had residual mass (>0 mm) after primary cytoreduction and 11 (18%) received neo-adjuvant chemotherapy. Ki67 ≥3.6% was associated with higher risk of residual mass after surgery (OR 8.1, 95% CI 1.45 to 45.18; p=0.017). Patients with Ki67 <3.6% showed a therapy-free interval of ≥6 months more often (OR 13.9, 95% CI 1.62 to 118.40; p=0.016). In the multivariate analysis of TFI <6 months, including CA125, age at diagnosis, peritoneal carcinomatosis, and ascites, Ki67 <3.6% remained a significant prognostic factor (OR 18.8, 95% CI 1.77 to 199.09; p=0.015). Chemotherapy responsiveness was evaluated in 21 patients who had residual disease and/or received neo-adjuvant chemotherapy. Ki67 ≥4.0% (OR 44.1, 95%CI 2.36-825.17, p = 0.011) was related to a significantly higher response rate (complete and partial response).

CONCLUSIONS

This is the first study to show an association between Ki67 expression and chemotherapy response, duration of TFI to platinum-based chemotherapy as well as outcome of surgery in low-grade serous ovarian cancers. Further prospective trials should use Ki-67 as a stratification factor to explore the effect of chemotherapy and endocrine strategies.

Immunohistochemistry for the detection of BRCA1 and BRCA2 proteins in patients with ovarian cancer: a systematic review

BACKGROUND

Loss of function in either breast cancer type 1 susceptibility protein (BRCA1) or breast cancer type 2 susceptibility protein (BRCA2) is a major risk factor for epithelial ovarian cancer (EOC) development. BRCA1 or BRCA2 deficiencies are associated with short-term prognosis and might have importance for the treatment of women with the disease. However, the screening of all possible mechanisms of dysfunction is expensive, time-consuming and difficult to apply in clinical practice. On the other hand, immunohistochemistry (IHC) is a simple and reliable method to access the expression of several proteins in tumour tissues.

MATERIALS AND METHODS

This systematic review aims to evaluate the current usage of IHC to detect BRCA1 and BRCA2 deficiencies in EOC. We searched and evaluated all primary literature on the use of IHC for evaluating BRCA1 and BRCA2 proteins expression in EOC. The main concepts for the search were: ovarian neoplasms, IHC, BRCA1 and BRCA2.

RESULTS

Forty-four studies from 925 unique titles were included. A total of 4206 tumour samples were evaluated for BRCA1 and 1041 for BRCA2 expression. Twelve BRCA1 primary antibodies were used in 41 studies, and the most common was the MS110 clone (75.6%). Seven BRCA2 primary antibodies were used in ten studies. Using the cut-off of 10%, 47.0% of EOCs are associated with loss of BRCA1 and 34.5% with the loss of BRCA2 expression.

CONCLUSION

IHC was effective to detect loss of BRCA1 protein expression in EOC; however, data on BRCA2 expression were heterogeneous and difficult to interpret.

The detrimental effect of adopting interval debulking surgery in advanced stage low-grade serous ovarian cancer

OBJECTIVE

To examine outcomes of patients having treatments for newly diagnosed advanced stage low-grade serous ovarian cancer (LGSC).

METHODS

We conducted a retrospective case series of women affected by advanced stage (stage IIIB or more) LGSC undergoing surgery in a single oncologic center between January 2000 and December 2017. Survival outcomes were assessed using Kaplan-Meier and Cox models.

RESULTS

Data of 72 patients were retrieved. Primary cytoreductive surgery was attempted in 68 (94.4%) patients: 19 (27.9%) had residual disease (RD) >1 cm after primary surgery. Interval debulking surgery (IDS) was attempted in 15 of these 19 (78.9%) patients and the remaining 4 patients having not primary debulking surgery. Twelve out of 19 (63.1%) patients having IDS had RD. After a mean (±standard deviation) follow-up was 61.6 (±37.2) months, 50 (69.4%) and 22 (30.5%) patients recurred and died of disease, respectively. Via multivariate analysis, non-optimal cytoreduction (hazard ratio [HR]=2.79; 95% confidence interval [CI]=1.16-6.70; p=0.021) and International Federation of Obstetrics and Gynecologists (FIGO) stage IV (HR=3.15; 95% CI=1.29-7.66; p=0.011) were associated with worse disease-free survival. Via multivariate analysis, absence of significant comorbidities (HR=0.56; 95% CI=0.29-1.10; p=0.093) and primary instead of IDS (HR=2.95; 95% CI=1.12-7.74; p=0.027) were independently associated with an improved overall survival.

CONCLUSION

LGSC is at high risk of early recurrence. However, owing to the indolent nature of the disease, the majority of patients are long-term survivors. Further prospective studies and innovative treatment modalities are warranted to improve patients care.

Prognostic significance of β-catenin expression in patients with ovarian cancer: A meta-analysis

AIM

The purpose of this study was to evaluate the impact of β-catenin immunohistochemical expression on the prognostic of ovarian cancer (OC) for that β-catenin could be responsible for the development and progress of OC.

METHODS

We searched various databases to identify eligible studies, and Review Managers 5.2 software was fulfilled in the meta-analysis.

RESULTS

A total of 11 studies were defined and composed in 1858 cases. β-catenin expression was significantly correlated with poor overall survival (OS) in OC patients (HR: 2.48, 95% CI: 1.38-4.47, P = 0.003), and showed a significant degree of heterogeneity (I² = 83%, P < 0.00001). Subgroup analysis indicated that accumulation in the nucleus and/or cytoplasm, rather than membrane, considerably influences the survival of OC patients independently.

CONCLUSION

Nucleus and/or cytoplasma of β-catenin expression might be associated with tumor progression and could be a possible potential predictive factor of poor prognosis in OC patients.