Anais Malpica

Grading ovarian serous carcinoma using a two-tier system.

In this study, we evaluate a two-tier system for grading ovarian serous carcinoma. This system is based primarily on the assessment of nuclear atypia with the mitotic rate used as a secondary feature. The study included 50 cases of low-grade ovarian serous carcinoma and 50 cases of high-grade ovarian serous carcinoma retrieved from the files of the Department of Pathology at the University of Texas M. D. Anderson Cancer Center from a 28-year period. Cases assigned to the low-grade category were characterized by the presence of mild to moderate nuclear atypia. As a secondary feature, they tended to show up to 12 mitoses per 10 high power fields (HPFs), whereas those in the high-grade category had marked nuclear atypia and as a secondary feature more than 12 mitoses per 10 HPFs. For comparison, the tumors were also graded using the Shimizu/Silverberg and the FIGO grading systems. Patients in the low-grade ovarian serous carcinoma group ranged in age from 19 to 75 years (mean 41.7 years) while patients in the high-grade ovarian serous carcinoma group ranged in age from 27 to 76 years (mean 55 years). All of the cases except one were advanced FIGO stage. Using the Shimizu/Silverberg system, the low-grade ovarian serous carcinoma cases were distributed as follows: grade 1, 47 cases; grade 2, 3 cases. Using the FIGO grading system, 35 cases were grade 1 and 15 cases were grade 2. Regarding the high-grade ovarian serous carcinoma group using the Shimizu/Silverberg system, 14 of the cases were grade 2 and 36 cases were grade 3. Using the FIGO grading system, 1 case was grade 1, 38 cases were grade 2, and 11 cases were grade 3. Most of the patients in both groups were treated with total abdominal hysterectomy and bilateral salpingo-oophorectomy and also received cisplatinum-based chemotherapy. On follow-up, 37 patients in the low-grade ovarian serous carcinoma group had died of disease at a median 4.2 years after diagnosis compared with 46 patients in the high-grade ovarian serous carcinoma group who died of disease at a median of 1.7 years. Eight patients in the low-grade ovarian serous carcinoma group and 4 patients in the high-grade ovarian serous carcinoma group were alive with disease at median follow-ups of 4.3 and 3.85 years, respectively. Four patients with low-grade serous carcinoma were alive without evidence of disease after a follow-up that ranged from 4.4 to 22.6 years (median 6.85 years), and one died of other causes 14 years after the diagnosis of her ovarian tumor. On multivariate analysis, residual tumor and tumor grade based on the M. D. Anderson two-tier system for grading ovarian serous carcinoma were found to be significant independent prognostic factors (P = 0.003 and 0.04, respectively). Of interest, 60% of the low-grade ovarian serous carcinomas in this study were associated with a serous neoplasm of low malignant potential, whereas this association was present in only 2% of the high-grade ovarian serous carcinomas. This finding could reflect a difference in the pathogenesis of ovarian serous carcinomas of different grades. In summary, there is usually a good correlation between the two-tier grading system herein presented and the Shimizu/Silverberg and the FIGO grading systems. Because this system is based on defined criteria that are easy to follow and because it involves only two diagnostic categories, it should provide better reproducibility in the grading of ovarian serous carcinoma. However, additional studies are required to validate these statements.

C-met Proto-Oncogene Expression in Benign and Malignant Human Prostate Tissues

Previously, we demonstrated that hepatocyte growth factor/scatter factor (HGF/SF) is expressed by human bone stromal cells and is a powerful mitogen to prostatic epithelial cells in culture. Based on these observations, we hypothesized that, if prostate cancer cells in the prostate or bone environment respond to HGF/SF as a mitogen, then they must express the HGF/SF receptor, which is coded by the c-met proto-oncogene. We used immunohistochemical techniques to: 1) assess the presence and localization of c-met protein in benign and malignant human prostate tissues and 2) correlate the presence of c-met protein with tumor stage, grade and androgen sensitivity. c-met protein immunostaining was consistently observed in the basal epithelial layer of normal prostate glands but was absent in luminal epithelial cells of the peripheral and transition zones. c-met protein immunostaining was detected in 10 of 11 foci (91%) of high grade prostatic intraepithelial neoplasia (PIN). Overall, c-met protein staining was noted in 36 of 43 (84%) primary prostate cancer samples versus 2 of 11 (18%) benign prostate hyperplasia samples (p < 0.0001) and in 4 of 4 (100%) lymph node metastases, 23 of 23 (100%) bone marrow metastases and 1 of 3 (33%) other metastatic sites. There was a clear relationship between c-met protein staining and higher grade adenocarcinomas (p < 0.001). c-met protein is frequently detected in PIN and higher grade prostate cancers; future studies should evaluate the biological significance of these findings.

Understanding the contributions of NADH and collagen to cervical tissue fluorescence spectra: modeling, measurements, and implications.

OBJECTIVE At 380 nm excitation, cervical tissue fluorescence spectra demonstrate characteristic changes with both patient age and the presence of dysplasia. A Monte Carlo model was developed in order to quantitatively examine how intrinsic NADH and collagen fluorescence, in combination with tissue scattering and absorption properties, yield measured tissue spectra. METHODS Excitation-emission matrices were measured for live cervical cells and collagen gel phantoms. Fluorescence microscopy of fresh tissue sections was performed to obtain the location and density of fluorophores as a function of patient age and the presence of dysplasia. A Monte Carlo model was developed which incorporated measurements of fluorophore line shapes and spatial distributions. RESULTS Modeled spectra were consistent with clinical measurements and indicate that an increase in NADH fluorescence and decrease in collagen fluorescence create clinically observed differences between normal and dysplastic tissue spectra. Model predictions were most sensitive to patient age and epithelial thickness. CONCLUSIONS Monte Carlo techniques provide an important means to investigate the combined contributions of multiple fluorophores to measured emission spectra. The approach will prove increasingly valuable as a more sophisticated understanding of in vivo optical properties is developed.

Near-infrared Raman spectroscopy for in vitro detection of cervical precancers

Abstract— In this study, we investigate the potential of near‐infrared Raman spectroscopy to differentiate cervical precancers from normal tissues, inflammation and metaplasia and to differentially diagnose low‐grade and high‐grade precancers. Near infrared Raman spectra were measured from 36 biopsies from 18 patients in vitro. Detection algorithms were developed and evaluated relative to histopathologic examination. Algorithms based on empirically selected peak intensities, ratios of peak intensities and a combination of principal component analysis for data reduction and Fisher discriminant analysis for classification were investigated. Spectral peaks were tentatively identified from measured spectra of potential chromophores. Empirically selected normalized intensities can differentiate precancers from other tissues with an average sensitivity and specificity of 88 ± 4% and 92 ± 4%. Ratios of un‐normalized intensities can differentiate precancers from other tissues with a sensitivity and specificity of 82% and 88% and high‐grade from low‐grade lesions with a sensitivity and specificity of 100%. Using multivariate methods, intensities at eight frequencies can be used to differentiate precancers from all other tissues with a sensitivity and specificity of 82% and 92% in an unbiased test. Raman algorithms can potentially separate benign abnormalities such as inflammation and metaplasia from precancers. Comparison of tissue spectra to published and measured chromophore spectra indicate that the most likely primary contributors to the tissue spectra are collagen, nucleic acids, phospholipids and glucose 1‐phos‐phate. These results suggest that near‐infrared Raman spectroscopy can be used for cervical precancer diagnosis and may be able to accurately separate samples with inflammation and metaplasia from precancer.

Light scattering from cervical cells throughout neoplastic progression: influence of nuclear morphology, DNA content, and chromatin texture.

A number of noninvasive fiber optic optical technologies are under development for real-time diagnosis of neoplasia. We investigate how the light scattering properties of cervical cells are affected by changes in nuclear morphology, DNA content, and chromatin texture, which occur during neoplastic progression. We used a Cyto-Savant computer-assisted image analysis system to acquire quantitative nuclear features measurements from 122 Feulgen-thionin-stained histopathologic sections of cervical tissue. A subset of the measured nuclear features was incorporated into a finite-difference time-domain (FDTD) model of cellular light scattering. The magnitude and angular distribution of scattered light was calculated for cervical cells as a function of pathologic grade. The nuclear atypia strongly affected light scattering properties. The increased size and elevated DNA content of nuclei in high-grade lesions caused the most significant changes in scattering intensity. The spatial dimensions of chromatin texture features and the amplitude of refractive index fluctuations within the nucleus impacted both the angular distribution of scattering angles and the total amount of scattered light. Cellular scattering is sensitive to changes in nuclear morphology that accompany neoplastic progression. Understanding the quantitative relationships between nuclear features and scattering properties will aid in the development of noninvasive optical technologies for detection of precancerous conditions.

CERVICAL PRECANCER DETECTION USING A MULTIVARIATE STATISTICAL ALGORITHM BASED ON LASER-INDUCED FLUORESCENCE SPECTRA AT MULTIPLE EXCITATION WAVELENGTHS

Abstract— A portable fluorimeter was developed and utilized to acquire fluorescence spectra from 381 cervical sites in 95 patients at 337, 380 and 460 nm excitation immediately prior to colposcopy. A multivariate statistical algorithm was used to extract clinically useful information from tissue spectra acquired in vivo. Two full‐parameter algorithms were developed using tissue fluorescence emission spectra at all three excitation wavelengths (161 excitation‐emission wavelength pairs) for cervical precancer (squamous intraepithelial lesion [SIL]) detection: a screening algorithm that discriminates between SIL and non‐SIL with a sensitivity of 82 ± 1.4% and specificity of 68 ± 0.0%, and a diagnostic algorithm that differentiates high‐grade SIL from non‐high‐grade SIL with a sensitivity and specificity of 79 ± 2% and 78 ± 6%, respectively. Multivariate statistical analysis was also employed to reduce the number of fluorescence excitation‐emission wavelength pairs needed to redevelop algorithms that demonstrate a minimum decrease in classification accuracy. Two reduced‐parameter algorithms that employ fluorescence intensities at only 15 excitation‐emission wavelength pairs were developed: the screening algorithm differentiates SIL from non‐SIL with a sensitivity of 84 ± 1.5% and specificity of 65 ± 2% and the diagnostic algorithm discriminates high‐grade SIL from non‐high‐grade SIL with a sensitivity and specificity of 78 ± 0.7% and 74 ± 2%, respectively. Both the full‐parameter and reduced‐parameter screening algorithms discriminate between SIL and non‐SIL with a similar specificity (±5%) and a substantially improved sensitivity relative to Pap smear screening. A comparison of the full‐parameter and reduced‐parameter diagnostic algorithms to colposcopy in expert hands indicates that all three have a very similar sensitivity and specificity for differentiating high‐grade SIL from non‐high‐grade SIL.

Near-Infrared Raman Spectroscopy for in Vivo Detection of Cervical Precancers

This study evaluates the potential of near-infrared Raman spectroscopy for in vivo detection of squamous dysplasia, a precursor to cervical cancer. A pilot clinical trial was carried out at three clinical sites. Raman spectra were measured from one colposcopically normal and one abnormal area of the cervix. These sites were then biopsied and submitted for routine histologic analysis. Twentyfour evaluable measurements were made in vivo in 13 patients. Cervical tissue Raman spectra contain peaks in the vicinity of 1070, 1180, 1195, 1210, 1245, 1330, 1400, 1454, 1505, 1555, 1656, and 1760 cm−1. The ratio of intensities at 1454 to 1656 cm−1 is greater for squamous dysplasia than all other tissue types, while the ratio of intensities at 1330 to 1454 cm−1 is lower for samples with squamous dysplasia than all other tissue types. A simple algorithm based on these two intensity ratios separates high-grade squamous dysplasia from all others, misclassifying only one sample. Spectra measured in vivo resemble those measured in vitro. Cervical epithelial cells may contribute to tissue spectra at 1330 cm−1, a region associated with DNA. In contrast, epithelial cells probably do not contribute to tissue spectra at 1454 cm−1, a region associated with collagen and phospholipids.

Clinical behavior of stage II-IV low-grade serous carcinoma of the ovary

OBJECTIVE: To analyze the clinical behavior of patients with stage II-IV low-grade serous carcinoma of the ovary seen at our institution who underwent primary surgery followed by platinum-based chemotherapy. METHODS: Patients with stage II-IV low-grade serous carcinoma of the ovary from 1978 to 2003 were identified using existing databases. Clinicopathologic information was obtained from medical records. Progression-free survival and overall survival were estimated by the method of Kaplan and Meier. The log-rank test was used to compare differences between survival curves. Univariable and multivariable analyses were performed using Cox proportional hazards regression. RESULTS: We identified 112 eligible patients. Median age was 43 years.; 90% had stage III disease. Preoperative serum CA 125 was elevated in 86% of patients. The most common sites of extraovarian disease were omentum, fallopian tubes, pelvic peritoneum, and uterus. Response rate to platinum-based chemotherapy in 10 evaluable patients (15% of patients with gross residual disease) was 80%, and 42 patients underwent second-look surgery: microscopically negative findings, 2 (5%); microscopically positive disease, 13 (33%); macroscopically positive disease, 24 (62%); and insufficient information, 3 (7%). Median progression-free survival and overall survival times were 19.5 and 81.8 months. Persistent disease after primary chemotherapy was the only factor associated with shorter overall survival time (hazard ratio 3.46, 95% confidence interval 2.00–5.97, P<.001). CONCLUSION: Metastatic low-grade serous carcinoma of the ovary is characterized by young age at diagnosis and prolonged overall survival. Segregating women with this diagnosis in future clinical trials is warranted. LEVEL OF EVIDENCE: II-3

Autofluorescence Microscopy of Fresh Cervical-Tissue Sections Reveals Alterations in Tissue Biochemistry with Dysplasia ¶

Abstract Fluorescence spectroscopy offers an effective, noninvasive approach to the detection of precancers in multiple organ sites. Clinical studies have demonstrated that fluorescence spectroscopy can provide highly sensitive, specific and cost-effective diagnosis of cervical precancers. However, the underlying biochemical mechanisms responsible for differences in the fluorescence spectra of normal and dysplastic tissue are not fully understood. We designed a study to assess the differences in autofluorescence of normal and dysplastic cervical tissue. Transverse, fresh tissue sections were prepared from colposcopically normal and abnormal biopsies in a 34-patient study. Autofluorescence images were acquired at 380 and 460 nm excitation. Results showed statistically significant increases in epithelial fluorescence intensity (arbitrary units) at 380 nm excitation in dysplastic tissue (106 ± 39) relative to normal tissue (85 ± 30). The fluorophore responsible for this increase is possibly reduced nicotinamide adenine dinucleotide. Stromal fluorescence intensities in the dysplastic samples decreased at both 380 nm (102 ± 34 [dysplasia] vs 151 ± 44 [normal]) and 460 nm excitation (93 ± 35 [dysplasia] vs 137 ± 49 [normal]), wavelengths at which collagen is excited. Decreased redox ratio (17–40% reduction) in dysplastic tissue sections, indicative of increased metabolic activity, was observed in one-third of the paired samples. These results provide valuable insight into the biological basis of the differences in fluorescence of normal and precancerous cervical tissue.

Reflectance spectroscopy for in vivo detection of cervical precancer

Optical technologies, in particular fluorescence spectroscopy, have shown the potential to provide improved detection methods for cervical neoplasia that are sensitive and cost effective through accurate, objective, instantaneous point-of-care diagnostic tools. The specific goals of this study were to analyze reflectance spectra of normal and neoplastic cervical tissue in vivo and to evaluate the data for use in diagnostic algorithm development. Spectroscopic measurements were obtained at four distinct source-detector separations from 324 sites in 161 patients. As the source-detector separation increases, greater tissue depth is probed. The average spectra of each diagnostic class differed at all source-detector separations, with the greatest differences occurring at the smallest source-detector separations. Algorithms, based on principal-component analysis and Mahalanobis distance classification, were developed and evaluated for all combinations of source-detector separations relative to the gold standard of colposcopically directed biopsy. The diagnostic combination of squamous normal versus high-grade squamous intraepithelial lesions gave good discrimination with a sensitivity of 72% and a specificity of 81%; discrimination of columnar normal versus high-grade squamous intraepithelial lesions also was good, with sensitivity of 72% and specificity of 83%. Thus, reflectance spectroscopy appears promising for in vivo detection of cervical precancer. Strategies that combine fluorescence and reflectance spectroscopy may enhance the discrimination capabilities.