beta-catenin expression, DNA ploidy and clinicopathological features in ovarian cancer: a study in 253 patients.

The CTNNB1 gene and its product beta-catenin, a regulator of the Wnt signalling pathway, is often mutated and deregulated in human malignancies. Down stream targets of the Wnt signalling pathway are linked to genomic instability. In this study, the impact of beta-catenin expression on genomic instability in ovarian carcinoma, as determined by DNA ploidy, was investigated. Expression of beta-catenin was examined by immunohistochemistry in 253 ovarian carcinomas. The results were related to genomic instability and clinicopathological features of the patients. Membrane associated staining of beta-catenin was detected in nearly all cases with no correlation to clinical parameters. Most of the samples also had cytoplasmic (84%), while only 13% had nuclear beta-catenin localisation. A significant association between beta-catenin expression (cytoplasmic and nuclear) and histological subtype and degree of differentiation was observed. Nuclear beta-catenin was almost exclusively present in endometroid carcinomas. 53% of all endometroid tumours were positive for nuclear beta-catenin expression (P<0.0001). Mucinous carcinomas had the highest degree of cytoplasmic beta-catenin expression (92%), followed by endometroid (92%), mixed (90%), serous (82%), unclassified adenocarcinomas (81%), carcinomas clear cell and (70%), (P=0.01). Tumours with differentiation grade 1 (16%) and 2 (24%) had higher nuclear beta-catenin expression than grade 3 and clear cell carcinomas (6%) (P=0.012). Better prognostic outcome was found for patients with nuclear beta-catenin localisation as compared to the cases without (P=0.027). In conclusion, the study showed no correlation between beta-catenin expression in ovarian carcinoma and FIGO stage and genomic instability as determined by DNA ploidy status. However, nuclear beta-catenin expression was strongly associated with endometroid histological subtype. Finally, in ovarian cancer, although beta-catenin staining seems to be of prognostic importance with respect to nuclear staining in univariate analysis, only DNA ploidy status, histological grade and FIGO staging were of independent prognostic significance in multivariate analysis.

Risk markers of oral cancer in clinically normal mucosa as an aid in smoking cessation counseling.

PURPOSE: Quitting smoking may prevent oral cancer. Behavioral intervention to quit smoking may be more efficient if persons are assigned an individual risk of cancer. PATIENTS AND METHODS: In this prospective study, we provided counseling and behavioral intervention toward smoking cessation, supplemented by genetic analyses in clinically normal oral mucosa of heavy smokers. Measurement of serum cotinine was used to assess changes in smoking habits. RESULTS: In cytologic scrapings from 275 heavy smokers with clinically normal mucosa, we found tetraploidy in four and aneuploidy in 19 persons (23 of 275; 8%). Twenty one (91%) of 23 persons with aneuploidy had quit or reduced their smoking habits at the 3-month follow-up, 20 (87%) of 23 persons had done so at 12 months, and 21 (91%) of 23 persons had done so at 24 months. Fifty-one (20%) of the 252 persons without genetic changes in their mucosa had quit or reduced their tobacco habits at the 3-month follow-up, 23 (9%) had done so at 12 months, and 17 (7%) had done so at 24 months (P < .001). After 24 months, normalization of DNA content to diploidy was observed in two of four persons with tetraploid (50%), and in 11 of 19 persons (58%) with aneuploid scrapings. One patient developed an oral carcinoma in the floor of the mouth: this patient had an aneuploid scraping obtained 43 months earlier and developed a leukoplakia 28 months before the carcinoma. CONCLUSION: Risk markers of oral cancer are present in clinically normal mucosa of heavy smokers, and such findings enhance the adherence to smoking cessation on counseling. Cytogenetic aberrations may normalize after quitting smoking.

[Biology and treatment options during the development of prostate cancer]. / Biologi og behandlingsmuligheter ved utvikling av prostatakreft.

BACKGROUND: Compelling evidence indicates that environmental and life-style factors, in addition to well-known risk factors such as testosterone level and age, are important for the development of prostate cancer. METHODS: In this review we summarize up-to-date knowledge about carcinogenesis in the prostate. The review is based on our own clinical research experience in this field and relevant articles identified by a literature search in the Medline and PubMed databases. RESULTS: During carcinogenesis of the prostate, significant changes are consistently observed in several molecular pathways. These molecular pathways are possible targets for intervention directed at reversing, stopping, or delaying cancer development. Racial differences indicate that genetic factors are also important for the development of prostate cancer. Improved surrogate biomarkers are needed for appropriate initiation of therapy and in order to monitor response. INTERPRETATION: Prostate cancer might be targeted early in the course of the disease provided that suitable markers reflecting carcinogenesis are identified.

The evolution of predictive oncology and molecular-based therapy for oral cancer prevention.

More than 300,000 new cases worldwide are being diagnosed with oral squamous cell carcinoma annually. This aggressive epithelial malignancy is associated with a high mortality and severe morbidity among the long-term survivors. The ability to intervene prior to this advanced stage may improve treatment results. This requires the early identification of molecular events that represent early phases of malignant transition, which is possible through measurement of DNA ploidy in epithelial cells of oral leukoplakia. Recently, we showed that patients with aneuploid dysplastic oral lesions had a 96% rate of oral cancer (26 of the 27 patients received the diagnosis) with a 70% rate within three years, an 81% rate of subsequent cancer (22 of 27), a 74% rate of death from cancer (21 of 27) and virtually no help from complete resection-all hallmarks of biologically aggressive cancer. Standard treatment of oral leukoplakia-a precursor lesion of oral cancer-varies from watchful waiting to complete resection. We have recently demonstrated that complete resection of aneuploid oral leukoplakia does not prevent the occurrence of clinically aggressive and highly lethal oral cancer. Oral carcinogenesis is a complex multifocal process of multiclonal field carcinogenesis and intraepithelial clonal spread. The multifocal nature of early oral carcinogenesis may hinder local treatment modalities. Inhibitors of cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR), either alone or in combination, may be used for reversing or stopping the oral carcinogenesis at an early stage of disease. The failure of standard treatment to control aneuploid oral leukoplakia justifies clinical trials with new treatment modalities, such as systemic therapy with molecular targeting agents, which in patients with aggressive leukoplakia is tantamount to cancer therapy.

Oral cancer prevention and the evolution of molecular-targeted drug development.

The multifaceted rationale for molecular-targeted prevention of oral cancer is strong. Oral cancer is a major global threat to public health, causing great morbidity and mortality rates that have not improved in decades. Oral cancer development is a tobacco-related multistep and multifocal process involving field carcinogenesis and intraepithelial clonal spread. Biomarkers of genomic instability, such as aneuploidy and allelic imbalance, can accurately measure the cancer risk of oral premalignant lesions, or intraepithelial neoplasia (IEN). Retinoid-oral IEN studies (eg, of retinoic acid receptor-beta, p53, genetic instability, loss of heterozygosity, and cyclin D1) have advanced the overall understanding of the biology of intraepithelial carcinogenesis and of preventive agent molecular mechanisms and targets-important advances for monitoring preventive interventions and assessing cancer risk and pharmacogenomics. Clinical management of oral IEN varies from watchful waiting to complete resection, although complete resection does not prevent oral cancer in high-risk patients. New approaches, such as interventions with molecular-targeted agents and agent combinations in molecularly defined high-risk oral IEN patients, are urgently needed to reduce the devastating worldwide consequences of oral cancer.

Evaluation of genomic changes in a large series of malignant ovarian germ cell tumors--relation to clinicopathologic variables.

Malignant ovarian germ cell tumors (mOGCT) affect women in their reproductive years, making fertility-saving treatment important. A reliable prediction of the clinical behavior is essential for an optimal therapeutic approach. The genetic changes and molecular mechanisms underlying these rare tumors remain poorly understood. To address these issues, we performed DNA ploidy analysis by high-resolution image cytometry in a series of 47 mOGCT and correlated the findings with the DNA copy number changes detected by comparative genomic hybridization (CGH) and clinical outcome. Of 47 tumors, 15 were diploid, 14 were tetraploid, 2 were polyploid, and 13 were aneuploid. All the immature teratomas were diploid, in contrast to the dysgerminomas and endodermal sinus tumors. The International Federation of Gynecology and Obstetrics (FIGO) staging, residual tumors after surgery, and DNA ploidy distribution were significant, independent prognostic factors in survival analysis. The study revealed that the number of DNA copy number aberrations was increased in tetraploid and aneuploid tumors as compared to diploid tumors. Furthermore, a high percentage of aneuploid nuclei in a sample were associated with a complex CGH profile of the tumor in question. The present study confirms that DNA aneuploidy assessment by image analysis may be linked to genetic instability, which is detected as genetic aberrations by CGH. DNA ploidy gives significant prognostic information in addition to the clinical stage in mOGCT with FIGO stage II-IV.

The influence of resection and aneuploidy on mortality in oral leukoplakia.

BACKGROUND: Although the standard treatment of oral leukoplakia ranges from watchful waiting to complete resection, the value of these approaches is unknown. METHODS: We studied the relations among resection, ploidy status, and death from cancer in 103 patients with diploid dysplastic oral leukoplakia, 20 patients with tetraploid lesions, and 27 patients with aneuploid lesions. Data on cancer-specific mortality and treatment were obtained from the Cancer Registry of Norway, Statistics Norway, and chart reviews. RESULTS: Primary oral carcinoma developed in 47 of the 150 patients with leukoplakia (31 percent)--5 with diploid, 16 with tetraploid, and 26 with aneuploid leukoplakia--during a mean follow-up of 80 months (range, 4 to 237). The margin status of the initial leukoplakia resection had no relation to the development of oral cancer (P=0.95). Twenty-six of the 47 patients in whom cancer developed (4 with prior tetraploid and 22 with prior aneuploid lesions) had recurrences (55 percent); the recurrences were more frequently multiple and distant (within the oral cavity) among patients with aneuploid lesions than among those with tetraploid or diploid lesions. All 47 patients underwent a standard regimen of surgery and radiation, followed by chemotherapy in the 26 with recurrent cancer. Only patients with aneuploid leukoplakia died of oral cancer; the five-year rate of death from cancer was 72 percent. Aneuploidy-related first carcinomas were diagnosed at a more advanced stage than were carcinomas originating from diploid or tetraploid leukoplakia (P=0.03) and were more likely to be lethal regardless of the stage. CONCLUSIONS: Complete resection of aneuploid leukoplakia does not reduce the high risk of aggressive carcinoma and death from oral cancer.

Novel management of oral cancer: a paradigm of predictive oncology.

The rationale for molecular-targeted prevention of oral cancer is strong. Oral cancer is a major global threat to public health with 300,000 new cases diagnosed worldwide on an annual basis. Notably, the great morbidity and mortality rates of this devastating disease have not improved in decades. Oral cancer development is a tobacco-related multistep and multifocal process involving field carcinogenesis and intraepithelial clonal spread. Biomarkers of genomic instability, such as aneuploidy and allelic imbalance, can accurately measure the cancer risk of oral premalignant lesions or intraepithelial neoplasia (IEN). Retinoid-oral IEN studies (e.g., retinoid acid receptor-beta, p53, genetic instability, loss of heterozygosity, and cyclin D1) have advanced the overall understanding of the biology of intraepithelial carcinogenesis and preventive agent molecular mechanisms and targets, important advances for monitoring preventive interventions, assessing cancer risk, and pharmacogenomics. Clinical management of oral IEN varies from watchful waiting to complete resection, although complete resection does not prevent oral cancer in high-risk patients. New approaches, such as interventions with molecular-targeted agents and agent combinations in molecularly defined high-risk oral IEN patients, are urgently needed to reduce the devastating worldwide consequences of oral cancer.

Molecular based treatment of oral cancer.

Given the increase in the age distribution of the population, an increase in cancer incidence rates are to be expected. Oral cancer is a disfiguring disease that continues to increase in incidence, particularly in the young, and to an extent that cannot be fully explained by increased exposure to known risk factors. Despite extensive research on treatment modalities towards oral cancer, the 5-year survival rate of this disease has not been improved over the last 4-5 decades. These facts strongly favour chemoprevention-systemic medication to revert, stop, or delay the carcinogenic process-as an approach to treating oral cancer. A chemopreventive approach to oral cancer most likely should encompass a combination of drugs targeting metabolic pathways relevant to oral carcinogenesis. Candidate drugs are retinoids and selective inhibitors of cyclooxygenase-2, epidermal growth factor receptor (EGFR), and peroxisome proliferator activated receptors (PPARs). Chemopreventive trials so far have used surrogate intermediate biomarkers as measurement of treatment effect. However, the efficiency of any drug for chemopreventive use should be assessed through a prospective randomized trial and evaluated by the only definitive end point for prevention of cancer, the incidence rates of new carcinomas.

[Chemoprevention: treatment of persons at high risk of cancer]. / Kjemoprevensjon--primaerforebyggende behandling ved høy kreftrisiko.

BACKGROUND: Solid malignant tumours are still associated with high mortality and morbidity. Chemoprevention--long-term systemic therapy in order to revert, stop or at least delay the carcinogenic process--is a feasible therapeutic approach to persons at increased risk of cancer. METHODS: References for this review article were identified by a search of Medline and PubMed for the years 1990 to 2002; the keywords used were "chemoprevention", "tamoxifen", "COX-2 inhibitors", "NSAIDs", "SERM", "EGFR", "breast cancer", "familial adenomatous polyposis coli", "colorectal cancer", "lung cancer", and "prostate cancer". RESULTS: Long-term medical treatment of persons at high-risk of cancer may reduce the incidence of several types of malignancies. This approach requires early and reliable identification of persons at high risk. INTERPRETATION: Chemoprevention is likely to become important in the future treatment of breast cancer, colorectal cancer, lung cancer, prostate cancer and probably also other malignancies. In order to ensure treatment effect and to avoid unnecessary side effects, such treatment should be restricted to persons at high risk.

[Chemoprevention of oral cancer]. / Kjemoprevensjon av munnhulekreft.

BACKGROUND: Morbidity and mortality from oral cancer is still considerable, and has not improved significantly over the last four or five decades. Early preventive intervention in persons at high risk may improve treatment results. MATERIAL AND METHODS: This review is based on our previously published data and by searches in the Medline and PubMed databases, using the following terms as key words: "oral premalignancies", "oral leukoplakia", "tumour progression", "genomic instability", "aneuploidy", "prognosis", "head and neck cancer", and "chemoprevention". RESULTS: Chemoprevention requires the early and reliable identification of persons at high risk of cancer. Retinoids have a clinically documented effect towards head-and-neck cancer, but are associated with unacceptable side-effects. Coxibs and inhibitors of epidermal growth factor receptors are candidate agents for chemoprevention of oral cancer. INTERPRETATION: It is now possible to identify persons at high risk of developing oral cancer who may benefit from chemopreventive use of coxibs or inhibitors of epidermal growth factor receptors.

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.

Which putatively pre-malignant oral lesions become oral cancers? Clinical relevance of early targeting of high-risk individuals.

Oral squamous cell carcinomas continue to be a group of diseases with high mortality and increasing incidence rates, particularly among young individuals. This is a paradox finding, since most oral cancers are preceded - even by several years - by readily detectable mucosal changes, most often white or red patches (leukoplakias and erythroplakias, respectively). However, only a small fraction of leukoplakias or erythroplakias are related to cancer development, and the challenge has been to identify the high-risk lesions. From the vast literature on molecular markers in oral pre-cancer, no reliable prognostic marker for risk assessment in putatively pre-malignant lesions has emerged. For this reason, a wait-and-see approach has been adopted for this group of lesions. Recently published data point to gross genomic aberrations (DNA aneuploidy) as a tool for targeting patients at particular risk for future cancerous lesions in the oral cavity. Thus, DNA aneuploidy signalled a very high risk for subsequent development of carcinomas in a wide range of lesions from the oral mucous membrane, ranging from oral leukoplakias to oral erythroplakias and even including lesions that had been explicitly defined as being without a malignant potential by a group of trained pathologists. As an extension of research in oral pre-malignancies, the enzyme cyclooxygenase-2 (COX-2) seems to be enhanced specifically in high-risk oral lesions, as defined by the aberrant DNA content of their lesions. These data strongly indicate that COX-2 inhibitors (coxibs) should be investigated as chemopreventive agents in patients identified to be at high risk of developing oral cancer.

Impact of genomic instability in risk assessment and chemoprevention of oral premalignancies.

Head-and-neck cancer is a disfiguring disease with increasing incidence rates even in young people, whose exposure to known risk factors is limited. This emphasizes the importance of early identification, on an individual basis, of precursor lesions that will develop into carcinomas. The clinical value of identifying individuals at high risk of oral cancer is emphasized by the fact that these patients are likely to benefit from available chemopreventive measures, largely without adverse effects.

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.