Survival analysis in advanced epithelial ovarian carcinoma in relation to proliferative index of MIB-1 immunostaining

Exploring a multiparameter MRI-based radiomics approach to predict tumor proliferation status of serous ovarian carcinoma

OBJECTIVES

To develop a multiparameter magnetic resonance imaging (MRI)-based radiomics approach that can accurately predict the tumor cell proliferation status of serous ovarian carcinoma (SOC).

MATERIALS AND METHODS

A total of 134 patients with SOC who met the inclusion and exclusion criteria were retrospectively screened from institution A, spanning from January 2016 to March 2022. Additionally, an external validation set comprising 42 SOC patients from institution B was also included. The region of interest was determined by drawing each ovarian mass boundaries manually slice-by-slice on T2-weighted imaging fat-suppressed fast spin-echo (T2FSE) and T1 with contrast enhancement (T1CE) images using ITK-SNAP software. The handcrafted radiomic features were extracted, and then were selected using variance threshold algorithm, SelectKBest algorithm, and least absolute shrinkage and selection operator. The optimal radiomic scores and the clinical/radiological independent predictors were integrated as a combined model.

RESULTS

Compared with the area under the curve (AUC) values of each radiomic signature of T2FSE and T1CE, respectively, the AUC value of the radiomic signature (T1CE-T2FSE) was the highest in the training set (0.999 vs. 0.965 and 0.860). The homogeneous solid component of the ovarian mass was considered the only independent predictor of tumor cell proliferation status among the clinical/radiological variables. The AUC of the radiomic-radiological model was 0.999.

CONCLUSIONS

The radiomic-radiological model combining radiomic scores and the homogeneous solid component of the ovarian mass can accurately predict tumor cell proliferation status of SOC which has high repeatability and may enable more targeted and effective treatment strategies.

CRITICAL RELEVANCE STATEMENT

The proposed radiomic-radiological model combining radiomic scores and the homogeneous solid component of the ovarian mass can predict tumor cell proliferation status of SOC which has high repeatability and may guide individualized treatment programs.

KEY POINTS

• The radiomic-radiological nomogram may guide individualized treatment programs of SOC. • This radiomic-radiological nomogram showed a favorable prediction ability. • Homogeneous slightly higher signal intensity on T2FSE is vital for Ki-67.

Ki67 as a Predictor of Response to PARP Inhibitors in Platinum Sensitive BRCA Wild Type Ovarian Cancer: The MITO 37 Retrospective Study

BACKGROUND

There is compelling need for novel biomarkers to predict response to PARP inhibitors (PARPi) in BRCA wild-type (WT) ovarian cancer (OC).

METHODS

MITO 37 is a multicenter retrospective study aiming at correlating Ki67 expression at diagnosis with a clinical outcome following platinum treatment and PARPi maintenance. Clinical data were collected from high grade serous or endometroid BRCAWT OC treated with niraparib or rucaparib maintenance between 2010-2021 in 15 centers. Ki67 expression was assessed locally by certified pathologists on formalin-fixed paraffin embedded (FFPE) tissues. Median Ki67 was used as a cut-off.

RESULTS

A total of 136 patients were eligible and included in the analysis. Median Ki67 was 45.7% (range 1.0-99.9). The best response to platinum according to median Ki67 was 26.5% vs. 39.7% complete response (CR), 69.1% vs. 58.8% partial response (PR), 4.4% vs. 1.5% stable disease (SD). The best response to PARPi according to median Ki67 was 19.1% vs. 36.8% CR, 26.5% vs. 26.5% PR, 26.5 vs. 25% SD, 27.9% vs. 16.2% progressive disease (PD). No statistically significant differences in progression free survival (PFS) and overall survival (OS) were identified between low and high Ki67. PFS and OS are in line with registration trials.

CONCLUSIONS

Ki67 at diagnosis did not discriminate responders to PARPi.

High Ki-67 expression is significantly associated with poor prognosis of ovarian cancer patients: evidence from a meta-analysis

OBJECTIVE

The prognostic significance of Ki-67 expression in patients with ovarian cancer was controversial in various studies. Therefore, we carried out a meta-analysis to determine the prognostic significance of Ki-67 in ovarian cancer patients.

METHODS

We searched PubMed, Cochrane Library, EMBASE, Web of Knowledge, China National Knowledge Infrastructure database and WanFang digital database for eligible studies from January 1, 1990 to June 1, 2017. The pooled hazard ratios and 95% confidence intervals were calculated to assess the prognostic significance of Ki-67 expression for overall survival in ovarian cancer patients.

RESULTS

Finally, 38 eligible studies and 5004 ovarian cancer patients were included in the current study. The pooled hazard ratio was 1.35 (95% confidence interval 1.24-1.46, P = 0.001) for overall survival in ovarian cancer patients. The funnel plot bias was obviously asymmetrical and Egger's test also detected significant publication bias (P = 0.001). The Contour-enhanced funnel plot with trim-and-fill method supplemented 11 dummy studies to balance the funnel plot and nine new supplementary studies were in area with statistical significance. Sensitivity analysis and cumulative meta-analysis further demonstrated that the association between high Ki-67 expression and poor overall survival of ovarian cancer patients was stable and reliable.

CONCLUSIONS

High Ki-67 expression is significantly related to poor overall survival and may serve as a prognostic biomarker for ovarian cancer patients.

Prognostic significance of Ki-67 levels and hormone receptor expression in low-grade serous ovarian carcinoma: an investigation of the Tumor Bank Ovarian Cancer Network

Low-grade serous ovarian carcinoma (LGSOC) has recently come up as a distinct rare entity of epithelial ovarian cancer. Predictive and prognostic markers are not well studied yet. Because Ki-67 and hormone receptors (HR) have been established as relevant cancer biomarkers in several malignant tumors, we evaluated Ki-67 and HR expression rates by immunohistochemistry in 68 patients with LGSOC. We used a standardized cutoff finder algorithm to analyze prognostic significance for overall survival (OS) and progression-free survival (PFS). Cox regression showed a significant continuous decrease in OS for higher proliferation rates with an HR  of 1.07% (95% confidence interval, 1.01%-3.67%; P = .048) but not in PFS (P = .86). Cutoff finder analysis revealed the best possible cutoff for OS at 6.28% (P = .04) and for PFS at 1.85% proliferative activity (P = .04). Estrogen receptors (ERs) were expressed in most LGSOC patients (n = 61; 89.7%), progesterone receptor (PR) in about half of patients (n = 33; 48.5%). For both ER/PR, a statistically significant cutoff for PFS could be determined, which was at 75% of positive tumor cells for ER (P = .02) and at 15% of positive tumor cells for PR (P = .03). For OS, HR expression showed a tendency toward better OS for HR-positive tumors but did not turn out statistically significant. Our results show that Ki-67 is a valuable prognostic marker in the subgroup of LGSOC. We could also show that most LGSOCs express HRs but that this expression is associated with a better PFS, a finding valuable in times of antihormonal therapy in LGSOC.

Diagnostic and Prognostic Significance of Ki-67 Immunohistochemical Expression in Surface Epithelial Ovarian Carcinoma

INTRODUCTION

The Surface Epithelial Ovarian Carcinoma (SEOC) at the moment of diagnosis, the disease is extended beyond the structures of the pelvis. Ki-67 is one of the prognostic marker which determines the growth fraction of a tumour and its over expression is associated with malignancy, tumour aggression, reserved prognosis and metastasis.

AIM

To evaluate the proliferative activity using Ki-67 immuno-staining in SEOC and to correlate with histological subtype, grade, Federation of Gynecology and Obstetrics (FIGO) stage, CA125 levels for diagnostic and prognostic purpose.

MATERIALS AND METHODS

The study was conducted in JSS Medical College and Hospital, JSS University, Mysuru. It was a descriptive cross-sectional study involving 40 cases of SEOC over a period of two years. The proliferation expression related to Ki-67 antigen was evaluated by immunohistochemical monoclonal MIB-1 antibody. In each case, the Ki-67 labeling index (Ki-67 LI) was articulated as percentage of positively stained cells using high power objective of the microscope (x400).

RESULTS

Among the 40 carcinomas, 26 were serous, five mucinous, four each of clear cell and undifferentiated and one transitional cell carcinoma. A total of 75% were high grade tumours. High Ki-67 LI was associated with high grade tumours (69.9%), high grade serous tumours (65.34%) and advanced FIGO staging (70.6%) with the p-value of <0.001. CA 125 levels did not have a significant correlation with Ki-67 LI.

CONCLUSION

Ki-67 is an exceptionally a cost effective marker to determine the growth fraction of a tumour cell population. In SEOC histological grade and FIGO stage when combined with Ki-67 LI in histopathology report would help in diagnostic differentiation of subtypes, prognostication, deciding the need for adjuvant chemotherapy and in predicting survival analysis.

The prognostic role of Ki-67/MIB-1 in cervical cancer: a systematic review with meta-analysis

BACKGROUND

A significant relationship has been reported in which Ki-67/MIB-1 expression is correlated with survival in cervical cancer patients. However, the prognostic value of Ki-67/MIB-1 in cervical cancer is still not well understood.

MATERIAL AND METHOD

A meta-analysis was carried out to explore the prognostic value of Ki-67/MIB-1 on overall survival (OS) and/or disease-free survival (DFS) in cervical cancer. The databases of PubMed, ISI Web of Science, EMBASE, Cochrane Central Register of Controlled Trials, ScienceDirect, and Wiley Online Library were used to identify relevant literature.

RESULTS

We included 18 studies covering 1344 patients in the meta-analysis. The effect of Ki-67/MIB-1 on OS for pooled random effects HR estimate was 1.63 (95% confidence intervals (CI) 1.09-2.45; P<0.05). Subgroup analysis by ethnicity suggested that high expression of Ki-67/MIB-1 had association with Asians (1.84, 95% CI 1.04-3.23), but not with Africans (HR=1.53, 95% CI 0.34-6.86) or Europeans (HR=1.29, 95% CI 0.74-2.23). Furthermore, subgroup analysis of diverse treatments revealed no difference in surgery (HR=1.97, 95% CI 0.78-4.99) and radiation therapy (RT) (HR=1.56, 95% CI 0.93-2.63). The pooled HR for DFS was 1.26 (95% CI 0.58-2.73; P>0.05) and the subgroup analysis indicated Ki-67/MIB1 was associated with DFS (HR=3.67, 95% CI 2.65-5.09) in Asians. In the treatment subgroup analysis, no direct value was found among surgery (HR=1.13, 95% CI 0.10-13.53) and RT (HR=1.26, 95% CI 0.71-2.24).

CONCLUSIONS

Our meta-analysis concludes that Ki-67/MIB-1 had a prognostic value for OS in cervical cancer patients. To further evaluate the prognostic role of Ki-67/MIB-1 on DFS, studies with larger numbers of patients are needed to validate our findings.

Immunohistochemical Evaluation of Minichromosome Maintenance Protein 7 (MCM7), Topoisomerase IIα, and Ki-67 in Diffuse Malignant Peritoneal Mesothelioma Patients Using Tissue Microarray

PURPOSE

Immunohistochemistry and tissue microarray (TMA) were used to perform a prognostic analysis of markers related to cell proliferation in diffuse malignant peritoneal mesothelioma (DMPM).

METHODS

Clinicopathologic data were extracted from a prospectively collected database containing cases of peritoneal mesothelioma treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in the National Cancer Institute of Milan from 1995 to 2013. Eighty-one DMPM patients were recruited and their tissue samples were used to construct TMAs. We evaluated the immunoexpressions of markers related to cell proliferation-topoisomerase IIα, minichromosome maintenance protein 7 (MCM7), and Ki-67-and then conducted a multivariate Cox model to identify the predictors of overall survival (OS) and progression-free survival (PFS) among the following parameters: age, sex, Eastern Cooperative Oncology Group (ECOG) performance status, baseline serum albumin, Charlson Comorbidity Index, previous systemic chemotherapy, histological subtype (epithelioid vs. biphasic/sarcomatoid), peritoneal cancer index, completeness of cytoreduction (CC), and proliferative biological markers.

RESULTS

The rates of high/intermediate immunoreactivity were 95 % for topoisomerase IIα and 90 % for MCM7, and the median Ki-67 labeling index was 5 %. The independent predictors of OS were baseline serum albumin >3.5 g/dl, CC, and Ki-67 >5 %, whereas those for PFS were an ECOG performance status of 0, baseline serum albumin >3.5 g/dl, Charlson Comorbidity Index >3, previous systemic chemotherapy, morbidity G3-5, and Ki-67 >5 %. The remaining biological markers were not associated with outcome.

CONCLUSIONS

Ki-67 was found to be a new powerful determinant of outcome. Patients with a Ki-67 labeling index >5 % carry a very poor prognosis and do not benefit from the combined procedure. Further studies should be conducted to confirm the present data.

Ki-67 as an independent prognostic factor in an unselected cohort of patients with ovarian cancer: results of an explorative, retrospective study

The identification of prognostic markers has clinical implications in epithelial ovarian carcinoma (EOC). Here, we studied markers for proliferation (Ki-67), endocrine regulation [progesterone receptor (PR), estrogen receptor (ER)], and invasion [urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor (PAI-1)]. All patients with available follow-up information and EOC tissue, who were treated at our institution between 1997 and 2004, were enrolled in the present study. Expression of Ki-67, PR and ER was determined by immunohistochemical analyses. uPA and PAI-1 antigen levels were determined using enzyme‑linked immunosorbent assays. One hundred and eight patients entered the present study. The median follow-up time was 43.3 (range 11.4-68.0) months. In multivariable Cox regression analyses, Ki-67 expression showed an independent negative impact on disease-free survival (DFS) and overall survival (OS) [hazard ratio (HR) for DFS, 11.5; 95% confidence interval (CI), 2.64-49.7; p=0.001 and HR for OS, 21.2; 95% CI, 9.9-113.1; p<0.001]. After cut-off optimization, PR expression showed an independent positive impact on prognosis (HR for DFS, 0.15; 95% CI, 0.03-0.68; p=0.014 and HR for OS, 0.13; 95% CI, 0.03‑0.68; p=0.016). Furthermore, postoperative residual tumor burden and completeness of chemotherapy determined the prognosis. ER, uPA and PAI-1 were not associated with survival. PR and ER, and postoperative residual tumor burden and tumor stage showed a strong correlation in an explorative Spearman's rank correlation coefficient (rho=0.759 and rho=0.426, respectively). Ki-67 and cut-off optimized PR are independently associated with the prognosis of EOC. Further prospective studies are warranted to confirm these associations and to elucidate the underlying mechanisms.

Effects of cyclooxygenase inhibitors in combination with taxol on expression of cyclin D1 and Ki-67 in a xenograft model of ovarian carcinoma

The present study was designed to investigate the effects of cyclooxygenase (COX) inhibitors in combination with taxol on the expression of cyclin D1 and Ki-67 in human ovarian SKOV-3 carcinoma cells xenograft-bearing mice. The animals were treated with 100 mg/kg celecoxib (a COX-2 selective inhibitor) alone, 3 mg/kg SC-560 (a COX-1 selective inhibitor) alone by gavage twice a day, 20 mg/kg taxol alone by intraperitoneally (i.p.) once a week, or celecoxib/taxol, SC-560/celecoxib, SC-560/taxol or SC-560/celecoxib/taxol, for three weeks. To test the mechanism of the combination treatment, the index of cell proliferation and expression of cyclin D1 in tumor tissues were determined by immunohistochemistry. The mean tumor volume in the treated groups was significantly lower than control (p < 0.05), and in the three-drug combination group, tumor volume was reduced by 58.27% (p < 0.01); downregulated cell proliferation and cyclin D1 expression were statistically significant compared with those of the control group (both p < 0.01). This study suggests that the effects of COX selective inhibitors on the growth of tumors and decreased cell proliferation in a SKOV-3 cells mouse xenograft model were similar to taxol. The three-drug combination showing a better decreasing tendency in growth-inhibitory effect during the experiment may have been caused by suppressing cyclin D1 expression.

Correlation of p53 and Ki-67 (MIB-1) expressions with clinicopathological features and prognosis of early stage cervical squamous cell carcinomas

AIM

To evaluate the prognostic significance of the expression of p53 and Ki-67, and their correlation with various clinicopathological factors in patients with squamous cell carcinoma of the uterine cervix treated by radical hysterectomy.

METHODS

Two hundred and thirty five patients diagnosed between 1987 and 2004 were investigated for p53 and Ki-67 expression by immunohistochemistry. The relationship of these proteins and other potential prognostic factors with recurrence-free survival (RFS) was evaluated.

RESULTS

The mean age of the patients was 43.9 years (range, 27-68). There were 28 cases with stage IA2 (11.9%) and 207 cases with stage IB1 (88.1%). The overall 5-year RFS was 91.1% (95% confidence interval [CI] 86.0, 94.4). p53 and Ki-67 expressions were seen in 33.6% and 81.3% of cases, respectively. p53 expression was significantly associated only with parametrial or marginal involvement (P = 0.005), while Ki-67 expression significantly correlated only with larger tumor (P = 0.011) and parametrial or marginal involvement (P = 0.024). There was significant correlation between the expression of p53 and Ki-67 (P = 0.021). In multivariate analysis, Ki-67 expression (hazard ratio for >or=3rd vs 1st tertile [>or=30% vs <20% expression] = 16.0, 95%CI 2.1-124.5; P = 0.0015) appeared to be an independent prognostic factor for RFS, while no prognostic significance of p53 expression was found.

CONCLUSION

Ki-67 expression is an independent prognostic parameter for RFS in patients with early stage squamous cell carcinoma of the uterine cervix. Ki-67 expression at or above the cut-off point of 30.0% had significantly poorer RFS.

Predictive and prognostic protein biomarkers in epithelial ovarian cancer: recommendation for future studies

Epithelial ovarian cancer is the most lethal gynecological malignancy. Due to its lack of symptoms, this disease is diagnosed at an advanced stage when the cancer has already spread to secondary sites. While initial rates of response to first treatment is >80%, the overall survival rate of patients is extremely low, mainly due to development of drug resistance. To date, there are no reliable clinical factors that can properly stratify patients for suitable chemotherapy strategies. Clinical parameters such as disease stage, tumor grade and residual disease, although helpful in the management of patients after their initial surgery to establish the first line of treatment, are not efficient enough. Accordingly, reliable markers that are independent and complementary to clinical parameters are needed for a better management of these patients. For several years, efforts to identify prognostic factors have focused on molecular markers, with a large number having been investigated. This review aims to present a summary of the recent advances in the identification of molecular biomarkers in ovarian cancer patient tissues, as well as an overview of the need and importance of molecular markers for personalized medicine in ovarian cancer.

Targeting slow-proliferating ovarian cancer cells

Advanced ovarian cancer has a high rate of recurrence and mortality despite relative chemosensitivity at the time of initial treatment. Conventional chemotherapeutic agents typically target rapidly dividing cells. Disease relapse may therefore result from the survival and later emergence of latent slow-proliferating and/or quiescent cancer cells. We sought to identify drugs that target this cell population and to investigate the influence of these cells on outcome of patients in remission from advanced ovarian cancer. Drugs with increased efficacy against slower proliferating cells were identified using correlation-based screening of 44,657 compounds tested on the NCI-60 panel of cancer cell lines. Validation of candidates was performed in comparison with Cisplatin or Paclitaxel and by manipulation of proliferation rates by serum deprivation. Cytostatic and cytocidal effects were evaluated using MTT assays and active caspase-3 immunocytochemistry. Ki-67 proliferation indices were determined for tumors from 104 patients in remission. UCN-01 efficacy was correlated with longer doubling time among the NCI-60 cell lines (R = 0.54, p < 0.0001) and in a panel of 24 ovarian cancer cell lines (R = 0.42, p = 0.04), whereas this was not the case for Cisplatin (R = -0.10, p = 0.65) and Paclitaxel efficacy correlated with shorter doubling time (R = -0.52, p = 0.009). Cytostatic and cytocidal effects of UCN-01 were increased in serum-deprived cells. A low proliferation index was associated with presence of persistent disease at second-look surgery (p = 0.01) and poor survival (disease-free survival, p = 0.002; overall survival, p = 0.04). These results suggest that targeting quiescent ovarian cancer cells may be a worthwhile therapeutic approach to improving survival of women with ovarian cancer.

Cell proliferation activity unrelated to COX-2 expression in ovarian tumors

The objective of this study was to assess the expression of Cyclooxygenase-2 (COX-2) and cell proliferation activity (Ki67 expression) in benign, borderline, and malignant serous and mucinous ovarian tumors. Expression of COX-2 and Ki67 proteins were evaluated by immunohistochemistry, in paraffin-embedded sections of ovarian epithelial tumors. The study included 113 serous (67 benign, 15 borderline, and 31 malignant) and 85 mucinous (48 benign, 28 borderline, and 9 malignant) tumors, removed from women who underwent laparotomy between January 1997 and December 2003. From benign to malignant tumors, there was a progressive positive trend in COX-2 expression in both serous and mucinous tumors, more evident in mucinous ones (P < 0.001). Comparing histologic types, COX-2 expression was more prominent in serous than in mucinous benign tumors (P < 0.01), but this difference was not significant in the borderline (P= 0.11) or malignant categories (P= 0.71). There was a progressive Ki67 positivity in line with the tumor histologic gradient for both serous (P < 0.01) and mucinous lesions (P < 0.01), but this increasing expression did not correlate with COX-2 expression in the present series (P= 0.78). There was a higher COX-2 expression in serous ovarian adenomas than in mucinous ones. COX-2 positivity increases in line with the morphologic gradient, from benign to malignant in both histologic types, but it was more prominent in mucinous lesions, pointing to different oncogenic pathways related to different histologic types. A correlation between the expression of COX-2 and Ki67 was not found, suggesting that COX-2 may be required for carcinogenesis, but this pathway is not responsible for cell proliferation in ovarian tumors.

WT1 gene expression as a prognostic marker in advanced serous epithelial ovarian carcinoma: an immunohistochemical study

BACKGROUND

WT1 is a tumor suppressor gene responsible for Wilms' tumor. WT1 reactivity is limited to ovarian serous carcinomas. Recent studies have shown that WT1 plays an important role in the progression of disease and indicates a poorer prognosis of human malignancies such as acute myeloid leukemia and breast cancer. The aims of this study were to determine the survival and recurrence-free survival of women with advanced serous epithelial ovarian carcinoma in relation to WT1 gene expression.

METHODS

The study accrued women over an 18-year period, from 1987-2004. During the study period, 163 patients were diagnosed with advanced serous epithelial ovarian carcinoma and had undergone complete post-operative chemotherapy, but the final study group comprised 99 patients. The records of these women were reviewed and the paraffin-embedded tissue of these women stained with WT1 immunostaining. Survival analysis was performed using Kaplan-Meier and Cox regression methods.

RESULTS

Fifty patients showed WT1 staining and forty-nine did not. Five-year survival of non-staining and staining groups were 39.4% and 10.7% (p < 0.00005); five-year recurrence-free survival of these groups were 29.8% and < or = 7.5% (p < 0.00005), respectively. For survival the HR of WT1 staining, adjusted for residual tumor and chemotherapy response, was 1.98 (95% CI 1.28-3.79), and for recurrence-free survival the HR was 3.36 (95% CI 1.60-7.03). The HR for recurrence-free survival was not confounded by any other variables.

CONCLUSION

This study suggests that expression of WT1 gene may be indicative of an unfavorable prognosis in patients with advanced serous epithelial ovarian carcinoma.