Past Successes

SPOCCS I and SPOCCS II

We initially began our work in China because the rates of cervical cancer in rural China were reported to be very high. The Shanxi Province Cervical Cancer Screening Study (SPOCCS) was designed to determine the sensitivity and specificity (critical in low resource settings) of five screening technologies in order to develop low-cost screening for rural China. We searched for a screening algorithm that was sensitive for cervical intraepithelial neoplasia (CIN) II, III, and cancer, and highly specific for CIN II and III. With such an algorithm, it would be possible to ablate the transformation zone of the cervix in test positive subjects without histological confirmation of the diagnosis. A pilot study of 136 women between the ages of 30 and 45 years was conducted in Xiangyuan and Yangcheng counties in southern Shanxi Province where we confirmed the high prevalence of disease and the feasibility of doing these types of studies in a remote rural environment.

The Shanxi Province Cervical Cancer Screening Study I (SPOCCS I) is a cross-sectional screening study of 5 screening technologies. The design of the study has served as a model for similar studies. In rural Shanxi Province, China, we examined 1997 women ages 35-45. Each subject underwent a self-test for HPV (by HC-II assay), fluorescence spectroscopy, liquid based cytology (ThinPrep)(read manually and used as a direct test for HPV), a visual inspection (VIA) diagnosis, and colposcopy with multiple cervical biopsies (see chart below). Our biopsy protocol serves as the critical element in our studies because it results in data with minimal verification bias. The POI micro-biopsy protocol that we have used for more than a decade has been central to our work.

Test Sensitivity and Specificity – SPOCCS I

	# Positive	Sensitivity for ³CIN II	Specificity for ³CIN II	Sensitivity for ³CIN III	Sensitivity for Cancer
HPV Self-Test ( ³1.0 pg/ml)	17% 340/1,997	83% 71/86	86%	81% 35/43	75% 9/12
Fluorescence Spectroscopy **	91% 1,759/1,934	94% 81/86	9%	93% 40/43	100% 12/12
ThinPrep® Pap ( ³ASCUS)	25% 506/1,997	94% 81/86	78%	98% 42/43	100% 12/12
HPV Direct Test ( ³ 1.0 pg/ml)	18% 364/1,997	95% 82/86	85%	98% 42/43	100% 12/12
Visual Inspection (Any abnormal)	28% 552/1,997	71% 61/86	74%	79% 34/43	67% 8/12
Colposcopy (Any abnormal)	26% 519/1,997	81% 70/86	77%	91% 39/43	100% 12/12

In SPOCCS I (above) a fluorescence spectroscopy** device that worked well in the esophagus was unable to overcome the cervical inflammation that was not present in U.S. testing, but is present so often in areas of the world with high rates of cervical cancer. This is an excellent example of the importance of not only tissue specific, but environment specific clinical validation.

SPOCCS II took place between October/2000 and April/2002. 8,497 women age 27 to 56 years were screened for cervical neoplasia with self test using a brush and direct test for high-risk HPV DNA (HC II) and liquid-based cytology (different version than in SPOCCS I). Again our biopsy protocol was used to ascertain the true diagnosis.

The SPOCCS I and II studies generated many important findings that have been published in the medical literature. Theses studies contain more than 20,000 matched colposcopic impressions and biopsies. In addition to the patient care that has been provided, one of the most important contributions from the SPOCCS studies are the clear documentation of the inaccuracy of colposcopy, the most commonly used imaging technology for the diagnosis of pre-invasive and invasive cancer of the cervix. As noted below, the sensitivity of colposcopy in SPOCCS I and II becomes even more interesting when one realizes the same prevalence of disease was found by less experienced colposcopists. Even though they did not identify as many areas of high grade disease using the colposcope (sensitivity) our biopsy protocol made their ascertainment of disease equal to the more experienced colposcopists. This study gives further strength to the importance of the biopsy protocol in the validation of new technology as well as in patient care.

	Sensitivity for >CIN II (based on the directed biopsy diagnosis)	Incidence > CIN II
SPOCCS I	65/86 ( 75.6%)	86/1997 (4.3%)
SPOCCS II	211/375 ( 56.3%)	375/8497 (4.4%)

Since colposcopy directed biopsy has been the standard for the confirmation of disease for more than 40 years, there are a multitude of published clinical studies whose reported results suffer from profound verification bias. Recently we re-analyzed the biopsies from SPOCCS I using a verage epithelial thickness (measured perpendicular to the epithelium with a micrometer) and the average nuclear density, to morphologically characterize our biopsies. We have determined that there are high grade lesions than are not visible with colposcopy and therefore responsible for a significantly large portion of false negative colposcopic exams. In addition there are benign thick lesions that are false positive diagnoses. It is clear we need to improve current imaging modalities.

Over the past few years one of the new imaging technologies we have been exploring is Optical Coherence Tomography an imaging technology that provides high definition in superficial tissue layers using infra-red. The first project, based primarily in Cleveland, attempted to develop OCT image criteria that could be used to clearly separate normal from abnormal cervical tissue. On completion of this initial experience with 50 patients we were quite confident we could differentiate between OCT images of normal cervix and OCT images of invasive cancer. OCT was able to visualize the normal microstructure of the various cervix anatomies.

In our second study, conducted primarily in the Dominican Republic (with a subpopulation from the Cleveland Clinic), 1215 OCT images with matched unmagnified visual inspection using acetic acid (VIA) and colposcope impressions and histology from 212 patients were assessed “remote from the time of the examination” by 3 reviewers. All patients had had VIA, OCT, colposcopy, and biopsies using our validation protocol. Both VIA and colposcopy showed improved specificity when combined with OCT. However, it was clear to us that “time-remote interpretation” of such a dynamic technology was sub-optimal. We have since done two real time studies in China. In Shenzhen, China 299 women were examined with the colposcope with a diagnostic impression made for each quadrant by the operating gynecologist. This was followed by OCT with real-time diagnostic impression and biopsies according to our standard micro-biopsy protocol. The result was a minimum of 4 biopsies per patient with matched OCT images and real-time impressions, plus matched digitized colposcopy images and colposcopy-based diagnoses from each patient. This was our first clinical investigation using the OCT technology “real time”. In addition to improving specificity we have identified two measurable OCT image characteristics that appear to be correlated with the evolving pathologic disease process.

In April of 2008 we completed the fourth of our planned clinical investigations, this time in the “Buyi-Miao Autonomous District of Guizhou Province China in collaboration with the Peking University Shenzhen Hospital and Preventive Oncology International, Inc. This study was designed to explore potential application of OCT technology in low-resource settings. Our primary objective was to determine the sensitivity, specificity, positive and negative predictive values for “real time” OCT just using the naked eye (VIA) to guide the OCT device. Our secondary objective was to examine the potential for OCT to improve the sensitivity and specificity of VIA and the ease of use of OCT in a real time clinical setting in a rural low resource environment. The subjects came from the surrounding villages of 4 main towns: Wengan, Sandu, Libo and Duyun, all in Guizhou Province, China. During the Guizhou trial there were several OCT observations noted, such as the “epithelial brightness” first discovered in our Shenzhen studies. However, we found ourselves confused by the multiple variables we have now identified and we were not able to adequately incorporate the change in brightness into our real-time “visual” interpretation. In fact we now believe that we have identified more image characteristics than we can possibly evaluate in real-time, without the help of a mathematical algorithm and “computer aided diagnosis.”

Statistical Significance Achieved for Epithelial Brightness as a Defining Characteristic to Evaluate Pre-invasive and Invasive Cervical Cancer

Observations made during our two China OCT studies led us to analyze the differences in the brightness of the cervical epithelium on Optical Coherence Tomography (OCT) images as a potential distinguishing characteristic of normal, low-grade, high-grade, and cancer histologies. The data from the 300 women who participated in a real-time study of OCT as a diagnostic adjunct to colposcopy and 183 women who participated in a real-time study of OCT as a diagnostic adjunct to VIA were combined to compare the relationship between the brightness of the OCT images to corresponding histology. Abnormal lesions were then measured for brightness; abnormal images were subsequently subtracted from the normal image to create a difference from normal. All brightness measures were a log scale. Mean difference from normal was used to compare brightness levels by histological grade. Two sample T-tests were used to look at differences in brightness between histological grades. Histologic diagnoses were as follows 6 squamousmetaplasia, 36 CIN II, 42 CIN III, and 8 cancer. 35 women with CIN II were availalbe for analysis. Mean brightness was 0.16, 1.56, 3.36, and 4.71 for squamous metaplasia, CIN II, CIN III, and cancer respectively. Mean brightness differed significantly between each histological grade (p-values 0.000) for the comparisons of CIN II to CIN III, CIN II to cancer, and squamous metaplasia to cancer. For the comparison of mean brightness for CIN III to cancer p=.008. We conclude that epithelial brightness is an important component to include in the development of mathematical algorithms to use for the diagnostic interpretation of OCT generated images of the uterine cervix.

OCT images from Optical Coherence Tomography use for Cervical Cancer

OCT image of a non-cancerous ectocervix	image of a precancerous (CIN III) ectocervix	OCT image of cancer of the ectocervix. E=epithelium S=stroma