Wanja Kildal

DNA CONTENT AS A PROGNOSTIC MARKER IN PATIENTS WITH ORAL LEUKOPLAKIA

BACKGROUND Oral leukoplakia may develop into squamous-cell carcinoma, which has a poor prognosis. Risk factors for oral carcinoma have been identified, but there are no reliable predictors of the outcome in individual patients with oral leukoplakia. METHODS We identified 150 patients with oral leukoplakia that was classified as epithelial dysplasia and measured the nuclear DNA content (ploidy) of the lesions to determine whether DNA ploidy could be used to predict the clinical outcome. Biopsy specimens obtained at annual follow-up visits were graded histologically and classified with respect to DNA content in a blinded fashion. Disease-free survival was assessed in relation to DNA ploidy and the histologic grade. The mean duration of follow-up was 103 months (range, 4 to 165). RESULTS Among 150 patients with verified epithelial dysplasia, a carcinoma developed in 36 (24 percent). Of the 150 patients, 105 (70 percent) had diploid (normal) lesions, 20 (13 percent) had tetraploid (intermediate) lesions, and 25 (17 percent) had aneuploid (abnormal) lesions at the time of the initial diagnosis. A carcinoma developed in 3 of the 105 patients with diploid lesions (3 percent), as compared with 21 of the 25 patients with aneuploid lesions (84 percent), yielding a negative predictive value of 97 percent with respect to the diploid lesions and a positive predictive value of 84 percent with respect to the aneuploid lesions. Carcinoma developed in 12 of 20 patients with tetraploid lesions (60 percent). The mean time from the initial assessment of the DNA content to the development of a carcinoma was 35 months (range, 4 to 57) in the group with aneuploid lesions and 49 months (range, 8 to 78) in the group with tetraploid lesions (P=0.02). The cumulative disease-free survival rate was 97 percent among the group with diploid lesions, 40 percent among the group with tetraploid lesions, and 16 percent among the group with aneuploid lesions (P<0.001). CONCLUSIONS The DNA content in cells of oral leukoplakia can be used to predict the risk of oral carcinoma.

Retracted: Comparison of histological grading and large‐scale genomic status (DNA ploidy) as prognostic tools in oral dysplasia

This article has been retracted. See retraction notice [DOI: 10.1002/path.2115].

Cyclooxygenase-2 (COX-2) expression in high-risk premalignant oral lesions.

Emerging data indicate a link between genetic instability and up-regulation of cyclooxygenase-2 (COX-2). To see if individuals at high risk of oral cancer are candidates for treatment with selective COX-2 inhibitors (coxibs), levels of COX-2 expression in healthy, premalignant and cancerous oral mucosa were compared with the occurrence of DNA ploidy status as a genetic risk marker of oral cancer. COX-2 gene product was evaluated immunohistochemically in 30 healthy persons, in 22 patients with dysplastic lesions without previous or concomitant carcinomas, and in 29 patients with oral carcinomas. The immunohistochemical findings were verified by western blotting. COX-2 expression was correlated to DNA content as a genetic risk marker of oral cancer. COX-2 was up-regulated from healthy to premalignant to cancerous oral mucosa. Thus, COX-2 expression was found in 1 case of healthy oral mucosa (3%). All specimens from healthy mucosa had a normal DNA content. In patients with premalignancies. In 29 patients with oral carcinomas, cyclooxygenase-2 expression was observed in 26 (88%), and aneuploidy was observed in 25 cases (94%, P=0.04). Notably, of 22 patients with dysplastic lesions, COX-2 was exclusively expressed in a subgroup of nine patients (41%) identified to be at high risk of cancer by the aberrant DNA content of their lesions. Seven of these patients were followed for 5 years or more. An oral carcinoma developed in six of them (85%; P=0.02). These findings emphasize the need to determine whether coxibs can reduce the risk of oral cancer in patients with high-risk precancerous lesions.

Gross Genomic Aberrations in Precancers: Clinical Implications of a Long-Term Follow-Up Study in Oral Erythroplakias

PURPOSE Gross genomic aberrations are increasingly seen as a cause rather than a consequence of carcinogenesis. Carcinomas may be prevented by systemically acting agents when used in high-risk individuals. If gross genomic aberrations could be shown to be predictive markers in precancers, they could serve as a tool for identifying high-risk individuals to be included in chemopreventive trials. PATIENTS AND METHODS To investigate the predictive power of gross genomic aberrations in several types of oral premalignancies, we analyzed 57 biopsies from oral erythroplakias of 37 patients, both histologically and for DNA content. DNA content was measured by high-resolution image cytometry, and distribution histograms of DNA content were generated and interpreted according to established protocols. The primary end point was cancer-free survival. RESULTS Fifty-seven dysplastic oral red lesions from 37 patients were investigated. Forty-one lesions from 25 patients were classified with aberrant DNA content (DNA aneuploidy), of which 23 patients (92%) later developed an oral carcinoma (after a median observation time of 53 months; range, 29 to 79 months). Of 12 patients having altogether 16 lesions with normal DNA content, none developed a carcinoma (median observation time, 98 months; range, 23 to 163 months; P <.001). In multivariate analysis, DNA content was a significant prognostic factor (P <.001), whereas histologic grade, sex, use of tobacco, size and location of lesions, and the presence multiple of lesions were not. CONCLUSION Gross genomic aberrations are highly predictive for the subsequent occurrence of carcinomas from a wide range of oral premalignancies.

RETRACTED: Abnormal DNA content predicts the occurrence of carcinomas in non-dysplastic oral white patches

The majority of oral squamous cell carcinomas (OSCCs) are preceded by visible changes in the oral mucosa, most often white patches. Although the histological finding of dysplasia in oral white patches signals increased risk of developing OSCC, this may also occur in non-dysplastic lesions. However, no reliable markers exist to predict the occurrence of OSCC in these patients. From a total of 263 patients diagnosed with oral white patches, biopsies from 45 patients were selected on the criteria that the patients had lesions histologically proven to be non-dysplastic. The lesions were analyzed with respect to their DNA content. The clinical outcome of the patients was known from the Cancer Registry of Norway, and these data were compared to the DNA content of their lesions. Among the 45 patients, five cases (11%) later developed an OSCC. Four of the cases that subsequently developed an OSCC were among the five aneuploid (abnormal) cases (P=0.001). One aneuploid lesion did not develop a carcinoma during a follow-up time of 120 months. The fifth case that subsequently developed an OSCC was diploid (normal), and developed into an OSCC after an observation time of 73 months (P=0.001). In conclusion, aberrant DNA content reliably predicts the occurrence of OSCC in patients that otherwise would be regarded as at very low risk. Normal DNA content indicates low risk.

Molecular based treatment of oral cancer

This article has been retracted at the request of Oral Oncology and the co-authors. Please see http://www.elsevier.com/locate/withdrawalpolicy . Reason: The lead author, Jon Sudbo, has been found by the Investigating Commission (appointed in January 2006 by Rikshospitalet - Radiumhospitalet MC and the University of Oslo to investigate Dr Sudbos misconduct) to have fabricated and modified the data on which the analyses were based. The above mentioned Investigating Commission has determined that Dr Sudbo acted alone in fabricating the data. Dr Sudbo disputes the findings of the Investigating Commission. Reference: Ekbom A, Helgesen GEM, Lunde T, Tverdal A, Vollset SE, Simonsen S. Report from the Investigating Commission appointed by Rikshospitalet - Radiumhospitalet MC and the University of Oslo, January 18, 2006.

β-Catenin expression in uterine sarcomas and its relation to clinicopathological parameters

Aberrations in the Wnt/beta-catenin signalling pathway are suggested as mediators of chromosomal instability and carcinogenesis. beta-catenin acts both as a component of the membranous adhesion system, and as a transcription activator in the nucleus. beta-Catenin immunoreactivity was evaluated in 353 uterine sarcomas (US) including 231 leiomyosarcomas (LMS), 82 endometrial stromal sarcomas (ESS), 22 adenosarcomas (AS) and 18 undifferentiated uterine sarcomas (UUS). Up-regulated membranous beta-catenin was observed in 25% of the LMS (p=0.039), 21% of the ESS (p=0.072) and 39% of the UUS (p=0.025). Cytoplasmic beta-catenin was up-regulated in 36% of the LMS (p=0.008) and 33% of the UUS (p=0.028). Nuclear beta-catenin expression was observed in 23% of the LMS (p=0.051), 61% of ESS (p=0.628) and in the sarcoma component of 68% of the AS. In patients with LMS, membranous beta-catenin was associated with poor crude survival in univariate (p=0.045), but not in multivariate analyses. In patients with ESS, nuclear beta-catenin expression was related to spread of tumour (p=0.033), but not to survival. The observation of up-regulated beta-catenin expression in US might suggest a so far undocumented role for the Wnt/beta-catenin pathway in these malignancies.

GENOME PROFILES OF BILATERAL DYSGERMINOMAS, A UNILATERAL GONADOBLASTOMA, AND A METASTASIS FROM A 46, XY PHENOTYPIC FEMALE

We present a case report of a 16-year-old, phenotypic female with bilateral dysgerminomas, a unilateral gonadoblastoma, and a peritoneal metastasis. The patients constitutional karyotype was 46,XY. The chromosomal copy number, examined by the comparative genomic hybridization technique, showed 3 gains in the dysgerminoma of the right ovary, 6 gains in the dysgerminoma of the left ovary, and 2 gains and 1 loss in the gonadoblastoma of the left ovary. The metastasis showed 5 gains of which 4 were also observed in the dysgerminoma of the left ovary. The DNA ploidy classifications of the gonadoblastoma and the dysgerminoma in the right ovary were tetraploid, whereas the dysgerminoma in the left ovary and the metastasis were aneuploid. We therefore propose that the metastasis most probably developed from the dysgerminoma of the left ovary.

Tumour heterogeneity poses a significant challenge to cancer biomarker research

Background:The high degree of genomic diversity in cancer represents a challenge for identifying objective prognostic markers. We aimed to examine the extent of tumour heterogeneity and its effect on the evaluation of a selected prognostic marker using prostate cancer as a model.Methods:We assessed Gleason Score (GS), DNA ploidy status and phosphatase and tensin homologue (PTEN) expression in radical prostatectomy specimens (RP) from 304 patients followed for a median of 10 years (interquartile range 6–12). GS was assessed for every tumour-containing block and DNA ploidy for a median of four samples for each RP. In a subgroup of 40 patients we assessed DNA ploidy and PTEN status in every tumour-containing block. In 102 patients assigned to active surveillance (AS), GS and DNA ploidy were studied in needle biopsies.Results:Extensive heterogeneity was observed for GS (89% of the patients) and DNA ploidy (40% of the patients) in the cohort, and DNA ploidy (60% of the patients) and PTEN expression (75% of the patients) in the subgroup. DNA ploidy was a significant prognostic marker when heterogeneity was taken into consideration. In the AS cohort we found heterogeneity in GS (24%) and in DNA ploidy (25%) specimens.Conclusions:Multi-sample analysis should be performed to support clinical treatment decisions.

Prognostic classification of early ovarian cancer based on very low dimensionality adaptive texture feature vectors from cell nuclei from monolayers and histological sections.

In order to study the prognostic value of quantifying the chromatin structure of cell nuclei from patients with early ovarian cancer, low dimensionality adaptive fractal and Gray Level Cooccurrence Matrix texture feature vectors were extracted from nuclei images of monolayers and histological sections. Each light microscopy nucleus image was divided into a peripheral and a central part, representing 30% and 70% of the total area of the nucleus, respectively. Textural features were then extracted from the peripheral and central parts of the nuclei images. The adaptive feature extraction was based on Class Difference Matrices and Class Distance Matrices. These matrices were useful to illustrate the difference in chromatin texture between the good and bad prognosis classes of ovarian samples. Class Difference and Distance Matrices also clearly illustrated the difference in texture between the peripheral and central parts of cell nuclei. Both when working with nuclei images from monolayers and from histological sections it seems useful to extract separate features from the peripheral and central parts of the nuclei images.