A new study of OVA1® clinical performance in the presurgical detection of ovarian cancer, entitled "Clinical Performance of a Multivariate Index Assay For Detecting Early-Stage Ovarian Cancer," has been published in The American Journal of Obstetrics & Gynecology.
Led by Dr. Robert E. Bristow (UC Irvine Healthcare) and Dr. Frederick R. Ueland (U. Kentucky), the new analysis focuses on presurgical detection of early-stage ovarian cancer among 1,016 ovarian mass surgery patients in two previous pivotal trials conducted in 2007 and 2012.
The study compared OVA1 performance in early-stage ovarian cancer to commonly used cancer risk assessment protocols: overall clinical assessment, the CA125 biomarker or modified-American College of Obstetricians and Gynecologists (mod-ACOG) guidelines for evaluation of suspicious pelvic masses. Vermillion, Inc. has reported the findings at the American Association of Gynecologic Laparoscopists "42nd AAGL Global Congress on Minimally Invasive Gynecology."
"Early-stage ovarian cancer constitutes an important opportunity to improve survival and care for this most deadly gynecologic cancer," said Dr. Bristow. "However, as evidenced by recent studies, most ovarian cancer patients fail to be referred to the doctors and hospitals best equipped to treat them, resulting in unfortunate consequences.
"Our new study demonstrates OVA1's ability to detect the majority of all early-stage ovarian cancers prior to surgery and thereby aid in appropriately involving a gynecologic oncologist in their care. Even among premenopausal patients where primary ovarian cancer prevalence was only 15%, clinical assessment with OVA1 detected early-stage ovarian cancer with nearly 90% sensitivity. This is a very encouraging development for diagnosis and treatment of ovarian cancer."
METHODS AND FINDINGS
As a benchmark of usual care, physicians were required to predict whether ovarian masses were malignant or benign following overall clinical assessment, which included physical examination and imaging, family history, and laboratory tests (including CA125, if used). Overall success of clinical assessment in predicting an early-stage malignancy (confirmed by pathology) was 68.6% (59 of 86 malignancies), while 31.4% were mistakenly predicted to be benign.
For stage I malignancies the percent detected fell to 63.9% (39/61), with 36.1% mistakenly predicted to be benign. Adding OVA1 to clinical assessment successfully identified 95.3% of early-stage cancers (82/86) and 93.4% of stage I malignancies (57/61) - a reduction in cancers missed of 85% (early-stage) and 82% (stage I), respectively over clinical assessment alone.
Among three risk-stratification methods compared directly for early-stage cancer detection, OVA1 showed the highest sensitivity (91.9%, or 79/86). OVA1 sensitivity was significantly higher than either benchmark method: sensitivity of the mod-ACOG guidelines was 76.7% (66/86) while CA125 sensitivity was 62.8% (54/86). The number of malignancies incorrectly stratified as low risk by CA125, mod-ACOG and OVA1 was 37.2%, 23.3% and 8.1%, respectively.
Early-stage cancer detection by OVA1 was 85.7% among premenopausal patients and 94.8% among postmenopausal patients. In contrast, CA125 alone correctly classified just 35.7% in premenopausal patients and 75.9% in postmenopausal patients. Used as intended together with clinical assessment, OVA1 sensitivity was 89.3% and 98.3% for pre- and post-menopausal early-stage cancer detection.
Dr. Donald Munroe, Vermillion's chief scientific officer and SVP of business development, commented: "Knowing the importance of referring early-stage ovarian cancer to gynecologic oncologists for optimal care, we are very encouraged by this latest clinical study. OVA1 significantly outperformed the three common risk assessment protocols in detecting early-stage cancers, which present the best opportunity for favorable outcomes or cure if appropriately handled. These results highlight the potential of OVA1 to replace the inferior off label use of CA125 and improve the presurgical management of ovarian cancer, which benefits patients, physicians and payers alike."