Molecular features as promising biomarkers in ovarian cancer

Ovarian cancer (OC) is a global challenge for modern medicine, ranking 7th for incidence and the 8th most common cause of mortality from cancers in women. Ovarian cancer has a poor prognosis, characterized by high morbidity and mortality, with detection occurring more frequently in advanced stages. Further issues lie within the heterogeneous nature of this pathology, as well as in its ability to develop multidrug resistance. Therefore, there is a burgeoning need to introduce effective screening for the general population, especially in high-risk groups such as individuals with a family history of cancer. Achieving this would be greatly assisted by identifying new biomarkers in order to, in turn, develop targeted therapies for patients. Advances in molecular biology techniques that enable cancer genetic characterization offer hope for personalized medicine. This article reviews the current findings on the biology of OC at the molecular level. Such knowledge may prove to be crucial and constitute a starting point for the development of new options for the early detection, prevention and treatment of OC.

Discovery and validation of serum glycoprotein biomarkers for high grade serous ovarian cancer

PURPOSE

This study aimed to identify serum glycoprotein biomarkers for early detection of high-grade serous ovarian cancer (HGSOC), the most common and aggressive histotype of ovarian cancer.

EXPERIMENTAL DESIGN

The glycoproteomics pipeline lectin magnetic bead array (LeMBA)-mass spectrometry (MS) was used in age-matched case-control serum samples. Clinical samples collected at diagnosis were divided into discovery (n = 30) and validation (n = 98) sets. We also analysed a set of preclinical sera (n = 30) collected prior to HGSOC diagnosis in the UK Collaborative Trial of Ovarian Cancer Screening.

RESULTS

A 7-lectin LeMBA-MS/MS discovery screen shortlisted 59 candidate proteins and three lectins. Validation analysis using 3-lectin LeMBA-multiple reaction monitoring (MRM) confirmed elevated A1AT, AACT, CO9, HPT and ITIH3 and reduced A2MG, ALS, IBP3 and PON1 glycoforms in HGSOC. The best performing multimarker signature had 87.7% area under the receiver operating curve, 90.7% specificity and 70.4% sensitivity for distinguishing HGSOC from benign and healthy groups. In the preclinical set, CO9, ITIH3 and A2MG glycoforms were altered in samples collected 11.1 ± 5.1 months prior to HGSOC diagnosis, suggesting potential for early detection.

CONCLUSIONS AND CLINICAL RELEVANCE

Our findings provide evidence of candidate early HGSOC serum glycoprotein biomarkers, laying the foundation for further study in larger cohorts.

Barriers of Care to Ovarian Cancer: A Scoping Review

Ovarian cancer is a leading cause of female cancer-related deaths, but patients continue to be diagnosed late. This subjects them to disease progression and possible death due to lack of early detection, despite earlier stage detection improving survival rates by significant percentages. Early detection and access to care are closely related. However, many barriers to high-quality care exist for patients and the majority of patients do not receive recommended care according to ovarian cancer treatment guidelines. In order to improve care for ovarian cancer patients and decrease healthcare disparities in accessing equitable care, it is important to acknowledge the current gaps in patient knowledge, healthcare availability, and physician practice. This scoping review explores the available evidence on ovarian cancer to identify these barriers to care in the effective treatment of ovarian cancer. Using both inclusion and exclusion criteria, results from the initial literature search were screened by the authors. After quality assessment and screening for relevance, 10 articles were included in the final review. The following themes emerged as barriers to care: hospital and physician-patient volumes, geographic distance from care facilities, patient and physician education, and demographic factors. Many patients were found to not receive guideline adherent care due to various barriers to care, whereas guideline adherent care was independently associated with factors such as patient proximity to a high-volume hospital, White race, and higher socioeconomic status. Several areas were identified as potential for increased patient and physician education, including treatment complications and patient resources. The evidence found that certain socioeconomic groups and racial minorities are often at higher risk for guideline non-adherent care. Additionally, the evidence showed a further need for physicians and healthcare providers to be provided with resources for post-cancer treatment, follow-up, and patient education. The findings of this review will provide health experts and patients with better insight into what barriers may exist so that guideline-adherent care can be better advocated for and met.

Ovarian cancer: Current status and strategies for improving therapeutic outcomes

Of all the gynecologic tumors, ovarian cancer (OC) is known to be the deadliest. Advanced‐stages of OC are linked with high morbidity and low survival rates despite the immense amount of research in the field. Shortage of promising screening tools for early‐stage detection is one of the major challenges linked with the poor survival rate for patients with OC. In OC, therapeutic management is used with multidisciplinary approaches that includes debulking surgery, chemotherapy, and (rarely) radiotherapy. Recently, there is an increasing interest in using immunomodulation for treating OC. Relapse rates are high in this malignancy and averages around every 2‐years. Further treatments after the relapse are more intense, increasing the toxicity, resistance to chemotherapy drugs, and financial burden to patients with poor quality‐of‐life. A procedure that has been studied to help reduce the morbidity rate involves pre‐sensitizing cancer cells with standard therapy in order to produce optimal results with minimum dosage. Utilizing such an approach, platinum‐based agents are effective due to their increased response to platinum‐based chemotherapy in relapsed cases. These chemo‐drugs also help address the issue of drug resistance. After conducting an extensive search with available literature and the resources for clinical trials, information is precisely documented on current research, biomarkers, options for treatment and clinical trials. Several schemes for enhancing the therapeutic responses for OC are discussed systematically in this review with an attempt in summarizing the recent developments in this exciting field of translational/clinical research.

Screening for ovarian cancer: imaging challenges and opportunities for improvement

The United Kingdom Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) recently reported a reduction in the average overall mortality among ovarian cancer patients screened with an annual sequential, multimodal strategy that tracked biomarker CA125 over time, where increasing serum CA125 levels prompted ultrasound. However, multiple cases were documented wherein serum CA125 levels were rising, but ultrasound screens were normal, thus delaying surgical intervention. A significant factor which could contribute to false negatives is that many aggressive ovarian cancers are believed to arise from epithelial cells on the fimbriae of the fallopian tubes, which are not readily imaged. Moreover, because only a fraction of metastatic tumors may reach a sonographically-detectable size before they metastasize, annual screening with ultrasound may fail to detect a large fraction of early-stage ovarian cancers. The ability to detect ovarian carcinomas before they metastasize is critical and future efforts towards improving screening should focus on identifying unique features specific to aggressive, early-stage tumors, as well as improving imaging sensitivity to allow for detection of tubal lesions. Implementation of a three-stage multimodal screening strategy in which a third modality is employed in cases where the first-line blood-based assay is positive and the second-line ultrasound exam is negative may also prove fruitful in detecting early-stage cases missed by ultrasound.

Sonographers' self-reported visualization of normal postmenopausal ovaries on transvaginal ultrasound is not reliable: results of expert review of archived images from UKCTOCS

OBJECTIVE

In the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS), self-reported visualization rate (VR) of the ovaries by the sonographer on annual transvaginal sonographic (TVS) examinations was a key quality control (QC) metric. The objective of this study was to assess self-reported VR using expert review of a random sample of archived images of TVS examinations from UKCTOCS, and then to develop software for measuring VR automatically.

METHODS

A single expert reviewed images archived from 1000 TVS examinations selected randomly from 68 931 TVS scans performed in UKCTOCS between 2008 and 2011 with ovaries reported as 'seen and normal'. Software was developed to identify the exact images used by the sonographer to measure the ovaries. This was achieved by measuring caliper dimensions in the image and matching them to those recorded by the sonographer. A logistic regression classifier to determine visualization was trained and validated using ovarian dimensions and visualization data reported by the expert.

RESULTS

The expert reviewer confirmed visualization of both ovaries (VR-Both) in 50.2% (502/1000) of the examinations. The software identified the measurement image in 534 exams, which were split 2:1:1 providing training, validation and test data. Classifier mean accuracy on validation data was 70.9% (95% CI, 70.0-71.8%). Analysis of test data (133 exams) provided a sensitivity of 90.5% (95% CI, 80.9-95.8%) and specificity of 47.5% (95% CI, 34.5-60.8%) in detecting expert confirmed visualization of both ovaries.

CONCLUSIONS

Our results suggest that, in a significant proportion of TVS annual screens, the sonographers may have mistaken other structures for normal ovaries. It is uncertain whether or not this affected the sensitivity and stage at detection of ovarian cancer in the ultrasound arm of UKCTOCS, but we conclude that QC metrics based on self-reported visualization of normal ovaries are unreliable. The classifier shows some potential for addressing this problem, though further research is needed. © 2017 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Complications from Surgeries Related to Ovarian Cancer Screening

The aim of this study was to evaluate complications of surgical intervention for participants in the Kentucky Ovarian Cancer Screening Program and compare results to those of the Prostate, Lung, Colorectal and Ovarian Cancer Screening trial. A retrospective database review included 657 patients who underwent surgery for a positive screen in the Kentucky Ovarian Cancer Screening Program from 1988–2014. Data were abstracted from operative reports, discharge summaries, and office notes for 406 patients. Another 142 patients with incomplete records were interviewed by phone. Complete information was available for 548 patients. Complications were graded using the Clavien–Dindo (C–D) Classification of Surgical Complications and considered minor if assigned Grade I (any deviation from normal course, minor medications) or Grade II (other pharmacological treatment, blood transfusion). C–D Grade III complications (those requiring surgical, endoscopic, or radiologic intervention) and C–D Grade IV complications (those which are life threatening) were considered “major”. Statistical analysis was performed using SAS 9.4 software. Complications were documented in 54/548 (10%) subjects. For women with malignancy, 17/90 (19%) had complications compared to 37/458 (8%) with benign pathology (p < 0.003). For non-cancer surgery, obesity was associated with increased complications (p = 0.0028). Fifty patients had minor complications classified as C–D Grade II or less. Three of 4 patients with Grade IV complications had malignancy (p < 0.0004). In the Prostate, Lung, Colorectal and Ovarian Cancer Screening trial, 212 women had surgery for ovarian malignancy, and 95 had at least one complication (45%). Of the 1080 women with non-cancer surgery, 163 had at least one complication (15%). Compared to the Prostate, Lung, Colorectal and Ovarian Cancer Screening trial, the Kentucky Ovarian Cancer Screening Program had significantly fewer complications from both cancer and non-cancer surgery (p < 0.0001 and p = 0.002, respectively). Complications resulting from surgery performed as a result of the Kentucky Ovarian Cancer Screening Program were infrequent and significantly fewer than reported in the Prostate, Lung, Colorectal and Ovarian Cancer Screening trial. Complications were mostly minor (93%) and were more common in cancer versus non-cancer surgery.

Subtypes of Ovarian Cancer and Ovarian Cancer Screening

Ovarian cancer is the foremost cause of gynecological cancer death in the developed world, as it is usually diagnosed at an advanced stage. In this paper we discuss current issues, the efficacy and problems associated with ovarian cancer screening, and compare the characteristics of ovarian cancer subtypes. There are two types of ovarian cancer: Type I carcinomas, which are slow-growing, indolent neoplasms thought to arise from a precursor lesion, which are relatively common in Asia; and Type II carcinomas, which are clinically aggressive neoplasms that can develop de novo from serous tubal intraepithelial carcinomas (STIC) and/or ovarian surface epithelium and are common in Europe and the USA. One of the most famous studies on the subject reported that annual screening using CA125/transvaginal sonography (TVS) did not reduce the ovarian cancer mortality rate in the USA. In contrast, a recent study in the UK showed an overall average mortality reduction of 20% in the screening group. Another two studies further reported that the screening was associated with decreased stage at detection. Theoretically, annual screening using CA125/TVS could easily detect precursor lesions and could be more effective in Asia than in Europe and the USA. The detection of Type II ovarian carcinoma at an early stage remains an unresolved issue. The resolving power of CA125 or TVS screening alone is unlikely to be successful at resolving STICs. Biomarkers for the early detection of Type II carcinomas such as STICs need to be developed.

Ovarian cancer screening effectiveness: A realization from the UK Collaborative Trial of Ovarian Cancer Screening

Effects on survival in the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) was reported in The Lancet, and demonstrate that reductions in disease-specific mortality in this randomized control trial (RCT) indicate that ovarian cancer screening works. The UKCTOCS was large enough for sufficient accrual and follow-up, using two intervention arms: MMS (a multimodal strategy using the biomarker Ca125 combined with ultrasound as a secondary test) and USS (ultrasound alone) compared against a no-screen control group. MMS and USS performed similarly, showing a statistically significant reduction in mortality that increased with follow-up surveillance (8% reduction in years 0-7 vs 28% in years 7-14). The data led to the estimate that 641 screens are needed to prevent one ovarian cancer death.

Clinical Efficacy of Ovarian Cancer Screening

Various trials of ovarian cancer screening programs have been reported worldwide. In 2011, one of the most famous papers indicated that annual screening using CA125/transvaginal sonography (TVS) did not reduce ovarian cancer mortality in the United States of America (USA). To investigate the validity of ovarian cancer screening, we verified the analyses of previous reports. At first, we obtained the USA datasets that were used for the analyses and identified many patients in whom cancers were accidentally detected several years after the screening period. We thus performed a new prognostic comparison between the screening group (cancers that were detected through screening or within one year after screening) and the control group (cancers that were found more than one year after screening, without screening, or in the original control group). The results showed that the prognoses of the screening group were significantly better than those of the control group (p=0.0017). In addition, the screening group contained significantly fewer stage IV cases than the control group (p=0.005). In another screening in the United Kingdom, ovarian cancer was detected at a relatively earlier stage (stage I/II: 44%), while the rate of stage IV detection was low (4%). Very recently, this team showed significant difference in the rates with and without screening (p=0.021) when prevalent cases were excluded and indicated the delayed effect of screening. These results contrasted with the USA data. In other studies in the USA and Japan, annual screening was also associated with a decreased stage at detection. New histopathological, molecular and genetic studies have recently provided two categories of ovarian carcinogenesis. Type I carcinomas are slow-growing neoplasms that often develop from benign ovarian cysts. Type II carcinomas are high-grade clinically aggressive neoplasms. The rate of type II carcinomas is significantly higher in Europe and the USA than in Asia (p<0.001). Conversely, type I carcinomas are relatively common in Asia. These data theoretically imply that annual screening would be more effective in Asia.

Quality assurance and its impact on ovarian visualization rates in the multicenter United Kingdom Collaborative Trial of Ovarian Cancer Screening (UKCTOCS)

OBJECTIVE

To describe the quality assurance (QA) processes and their impact on visualization of postmenopausal ovaries in the ultrasound arm of a multicenter screening trial for ovarian cancer.

METHODS

In the United Kingdom Collaborative Trial of Ovarian Cancer Screening, 50 639 women aged 50-74 years were randomized to the ultrasound arm and underwent annual transvaginal ultrasound (TVS) examinations. QA processes were developed during the course of the trial and included regular monitoring of the visualization rate (VR) of the right ovary. Non-subjective factors identified previously as impacting on VR of the right ovary were included in a generalized estimating equation model for binary outcomes to enable comparison of observed vs adjusted VR between individual sonographers who had undertaken > 1000 scans during the trial and comparison between centers. Observed and adjusted VRs of sonographers and centers were ranked according to the highest VR. Analysis of annual VRs of sonographers and those of the included centers was undertaken.

RESULTS

Between June 2001 and December 2010, 48 230 of 50 639 women attended one of 13 centers for a total of 270 035 annual TVS scans. One or both ovaries were seen in 228 145 (84.5%) TVS scans. The right ovary was seen on 196 426 (72.7%) of the scans. For the 78 sonographers included in the model, the median difference between observed and adjusted VR was -0.7% (range, -7.9 to 5.9%) and the median change in VR rank after adjustment was 3 (range, 0-18). For the 13 centers, the median difference between observed and adjusted VR was -0.5% (range, -2.2 to 1%), with no change in ranking after adjustment. The median adjusted VR was 73% (interquartile range (IQR), 65-82%) for sonographers and 74.7% (IQR, 67.1-79.0%) for centers. Despite the increasing age of the women being scanned, there was a steady decrease in the number of sonographers with VR < 60% (21.4% in 2002 vs 2.0% in 2010) and an increase in sonographers with VR > 80% (14.3% in 2002 vs 40.8% in 2010). The median VR of the centers increased from 65.5% (range, 55.7-81.0%) in 2001 to 80.3% (range, 74.5-90.9%) in 2010.

CONCLUSIONS

A robust QA program can improve visualization of postmenopausal ovaries and is an essential component of ultrasound-based ovarian cancer screening trials. While VR should be adjusted for non-subjective factors that impact on ovarian visualization, subjective factors are likely to be the largest contributors to differences in VR.

Risk perception, worry, and test acceptance in average-risk women who undergo ovarian cancer screening

OBJECTIVE

We evaluated baseline knowledge of ovarian cancer risk and perceptions toward ovarian cancer screening (OCS) by initiating the normal risk ovarian screening study.

STUDY DESIGN

Average-risk, postmenopausal women were enrolled between 2001 and 2011 as they entered the normal risk ovarian screening study. Participants completed baseline surveys of risk perception, cancer worry (Cancer Worry Scale), anxiety (State-Trait Anxiety Inventory), health and well-being survey (SF-36 HEALTH SURVEY), and acceptability of OCS.

RESULTS

Of the 1242 women who were enrolled, 925 women (74.5%) completed surveys. The respondents estimated a mean lifetime risk of ovarian cancer of 29.9%, which is much higher than the actual risk of 1.4% for women in the United States. Only 2.8% of participants correctly estimated their risk; 35.4% of the participants reported their lifetime risk to be ≥50%. Cancer worry was low, with a median Cancer Worry Scale score of 7 of 24. Anxiety was comparable with published norms for women in this age group, with median STAI-State and STAI-Trait scores of 30 and 29 of 80, respectively. Overall, women reported good physical and mental well-being. In terms of OCS acceptability, 97.2% of respondents agreed or strongly agreed that "the benefits of screening outweigh the difficulties." Very few women were reluctant to undergo OCS because of time constraints (1.1%), pain (2.0%), or embarrassment (1.9%).

CONCLUSION

Average-risk women who underwent OCS highly overestimated their risk of ovarian cancer. Despite this, participants reported low cancer worry and anxiety. The discrepancy between knowledge of and attitudes toward ovarian cancer risk highlights the need for educational efforts in this area.

A 2-stage ovarian cancer screening strategy using the Risk of Ovarian Cancer Algorithm (ROCA) identifies early-stage incident cancers and demonstrates high positive predictive value

BACKGROUND

A 2-stage ovarian cancer screening strategy was evaluated that incorporates change of carbohydrate antigen 125 (CA125) levels over time and age to estimate risk of ovarian cancer. Women with high-risk scores were referred for transvaginal ultrasound (TVS).

METHODS

A single-arm, prospective study of postmenopausal women was conducted. Participants underwent an annual CA125 blood test. Based on the Risk of Ovarian Cancer Algorithm (ROCA) result, women were triaged to next annual CA125 test (low risk), repeat CA125 test in 3 months (intermediate risk), or TVS and referral to a gynecologic oncologist (high risk).

RESULTS

A total of 4051 women participated over 11 years. The average annual rate of referral to a CA125 test in 3 months was 5.8%, and the average annual referral rate to TVS and review by a gynecologic oncologist was 0.9%. Ten women underwent surgery on the basis of TVS, with 4 invasive ovarian cancers (1 with stage IA disease, 2 with stage IC disease, and 1 with stage IIB disease), 2 ovarian tumors of low malignant potential (both stage IA), 1 endometrial cancer (stage I), and 3 benign ovarian tumors, providing a positive predictive value of 40% (95% confidence interval = 12.2%, 73.8%) for detecting invasive ovarian cancer. The specificity was 99.9% (95% confidence interval = 99.7%, 100%). All 4 women with invasive ovarian cancer were enrolled in the study for at least 3 years with low-risk annual CA125 test values prior to rising CA125 levels.

CONCLUSIONS

ROCA followed by TVS demonstrated excellent specificity and positive predictive value in a population of US women at average risk for ovarian cancer.

A qualitative study of women's experiences of familial ovarian cancer screening

OBJECTIVE

One risk management strategy that women at increased familial risk of ovarian cancer may use is screening. Until recently, this has been available as part of the UK Familial Ovarian Cancer Screening Study (UKFOCSS), using ultrasound scans of the ovaries and tumour marker blood tests. The present study aimed to gain an in-depth understanding of women's experiences of participating in ovarian cancer screening.

METHODS

Semi-structured interviews were conducted with 48 UKFOCSS participants. Interviews were recorded, transcribed and relevant sections analysed using a framework approach.

RESULTS

Screening provided women with reassurance which they found beneficial. A sense of privilege, as well as feeling proactive in potentially detecting ovarian cancer at an early stage was described. The wider benefit to research and the potential impact this could have on others was also important to women. Negative experiences of screening included worry about the screening tests and results, false reassurance by test results and disappointment with ineffective screening. Aspects of the screening study, such as the logistics, organisation and communication, were described as both good and problematic. When weighed up by the women, most described an overall positive experience of screening.

CONCLUSIONS

Women reported both positive and negative experiences of screening. Overall, screening seemed to be an acceptable risk management strategy to most women who participated in this interview study. Improvements could be made particularly in helping women to understand the limitations of familial ovarian cancer screening in order to avoid false reassurance.

A short history of sonography in obstetrics and gynaecology

The history of sonography in Obstetrics and Gynaecology dates from the classic 1958 Lancet paper of Ian Donald and his team from Glasgow. Fifty years on it is impossible to conceive of practising Obstetrics and Gynaecology without one of the many forms of ultrasound available today. Technological developments such as solid state circuitry, real time imaging, colour and power Doppler, transvaginal sonography and 3/4D imaging have been seized by clinical researchers to enhance the investigation and management of patients in areas as diverse as assessment of fetal growth and wellbeing, screening for fetal anomalies, prediction of pre-eclampsia and preterm birth, detection of ectopic gestation, evaluation of pelvic masses, screening for ovarian cancer and fertility management. Ultrasound guided procedures are now essential components of fetal therapy and IVF treatment. This concise history is written by someone who has witnessed each of these advances throughout the ultrasound era and is able to give perspective to these momentous happenings.